text:
Facts for Faith, Issue 7
- The Dynamics of Dating
- Exotic Life Sites: The Feasibility of Far-Out Habitats
- The Leap to Two Feet: The Sudden Appearance of Bipedalism
- Body and Soul Part II: Why the Soul is Immaterial
- A Salute to the General of Education: Mortimer J. Adler
- Reading Between the Fossil Lines
- Take a Tip from Columbo
- Speculations on Origins: Book Reviews of Investigations and Nature, Design, and Science
- A Stellar Array: An Interview with Dr. David Rogstad
- A New Direction for Stem Cell Research
- After Death I.D.—Will I Still Be Me?
- Creedal Controversy: The Orthodoxy of "Days"
The Dynamics of Dating
By Roger C. Wiens, PhD.
Bewildered, Janet watches her son gaze in awe at the dinosaur exhibit. A sign tells her that the Tyrannosaurus Rex is millions of years old. But last Sunday, her Bible teacher stated emphatically that God made Earth only six thousand years ago. The confusion over dates makes her stomach churn. The age assigned to the fossils in front of her seems to contradict the creation account, and Janet's heartbeats accelerate at the implication. Is Earth young or old? If old, did that mean the Bible is wrong? Or could science be wrong? And what is she going to tell her son?
Scientists agree that radiometric-dating techniques offer the most concrete evidence of any dating system for answering questions about the age of Earth. Yet, many people challenge the accuracy of radiometric dating, and misinformation describing the various radiometric techniques abounds. Debunking mysterious and complicated explanations of radiometric dating can be accomplished with a simple understanding of its general principles. Credible answers to common misconceptions about radiometric dating and a proper understanding of Scripture can help people like Janet reconcile creation accounts regarding the age of Earth.
General Principles of Radiometric Dating
Radiometric dating can be compared to an hourglass. When the timepiece is turned over, sand grains fall from the top of the hourglass to the bottom. No one can predict the moment when a particular grain will fall through the neck, but an estimate can be made for how long the whole pile of sand will take to fall.
A similar process takes place with the radioactive decay of atoms. (For a brief science review, see sidebar and figure 1.) The timepiece that allows dating is the "radioactive" decay of certain kinds of atoms from one form into another. Radioactive decay results from unstable combinations of protons and neutrons in the atom's nucleus. Though most atoms contain stable nuclei and do not decay, some types do. When radioactive decay occurs, no one can predict which individual atoms will decay when. But, for a large number of atoms, the number that will decay within a given time can be predicted. The original (parent) atom changes into a daughter atom having different chemical properties.
However, one significant difference exists between radiometric dating and the hourglass design. Unlike the hourglass, the rate of radioactive decays in a rock depends on the number of parent (original) atoms at any given time (N0). As fewer parent atoms are left, fewer decays occur. If it takes a certain length of time for half of the parent atoms of a radioactive isotope to decay (half-life), it will take the same amount of time for half of the remaining parent atoms (a fourth of the original total) to decay. In the next interval, with only a fourth remaining, only an eighth of the original total will decay. This produces an exponentially decreasing curve as described by the equation and displayed as the decreasing curved line in figure 2.
All radiometric dating is based on this very simple equation and the exponentially decreasing curve. In other words, N is the present abundance of parent atoms, the original abundance of parent atoms equals N0, t is time, and k is a constant related to the half-life (the time it takes for half of the parent atoms of a radioactive isotope to decay). The simplicity of this equation combined with the fact that it works with many different dating methods produces great confidence in its reliability.
An hourglass measures the specific amount of time that has passed since being turned over. Radiometric dating also tells how much time has passed since a particular event took place. For igneous rocks (those formed from magma or lava), the method measures how much time has passed since molten material cooled and turned into rock. In other cases, the event may be the end of a period of metamorphic heating (e.g., heating to over a thousand degrees Fahrenheit underground) or, for radiocarbon dating, the length of time since a plant or animal died. The different dating techniques provide accurate timetables for determining the age of rocks or other artifacts.
The Accuracy of Radiometric Dating. Though work on radiometric dating first started around 1910, relatively slow progress was made before the late 1940s. Many dating methods have now been tested and retested for over fifty years. Radiation detectors measure the half-lives of radioactive isotopes either directly by counting the number of atoms decaying in a given amount of time from a known amount of the parent material, or by measuring the ratio of daughter-to-parent atoms in a sample that originally consisted of parent atoms only. While the number of atoms to decay in fifty years may be a small fraction of the total, extremely precise counting of the daughter atoms can be accomplished.
Table I gives the half-lives for a few of the most commonly used radiometric dating methods. The uncertainty levels of these half-lives are very small—only about plus or minus 2 percent for all except for rhenium (5%), lutetium (3%), and beryllium (3%).1 At this level of certainty, though an age may vary by a small percentage, no question remains as to whether Earth was created recently, or a long time ago. However, to measure ages of things accurately, one must apply the appropriate dating method.
Which Dating Method is Appropriate? A number of different devices measure time in everyday life. A stopwatch measures time in a one-hundred-meter race. An ordinary alarm clock measures how long a person sleeps. A calendar counts the number of days before Christmas. A calendar can't measure time in the one-hundred-meter race, and a stopwatch can't measure the days before Christmas.
As with other timepieces, radiometric-dating methods must be appropriate to the sample being dated. Though many people are familiar with carbon-14 dating, this technique dates organic material such as bones, wood, cloth, paper, and other dead tissue from either plants or animals and is not effective for determining the age of rocks. The best results are usually obtained if one uses a method whose half-life lies within a factor of ten of the sample's estimated age. In the rare case that prior clues are absent, trying more than one method in order to obtain the correct age may be required. If the first attempt yields insufficient daughter atoms, a method with a shorter half-life needs to be tried, or samples with more parent atoms should be used in order for more daughter atoms to be present.
Most of the dating methods being discussed in the following paragraphs apply well when determining how long ago igneous rocks cooled and hardened from magma or lava. Atoms usually mix well in a liquid such as magma. When the molten material cools and hardens, the atoms no longer freely move about. Daughter atoms from radioactive decay occurring after the rocks cooled become trapped where they originated within the rocks. Like the sand grains accumulating in the bottom of the hourglass, the age of the rocks can be determined by measuring the number of daughter atoms and the number of remaining parent atoms, then using the half-life to calculate the time it took to make those daughter atoms.
However, a small complication remains. One cannot always assume that no daughter atoms existed to begin with, so the initial amount of the daughter product must be determined. Each dating method solves this problem in its own way. Particular types of dating work better in some rocks; others perform better in other rocks, depending on the rocks' composition and age.
Examples of Individual Dating Methods
Over forty different radiometric dating methods have been successfully used. Of these forty, three brief examples show how some of these methods work.
Potassium-Argon. Potassium, an abundant element in Earth's crust, has one radioactive isotope, of which 11.2 percent becomes the gas isotope, argon-40. Whenever rock melts and becomes magma or lava, the argon gas tends to escape. When the molten material hardens, argon (produced by later decays of potassium-40) is once again trapped. In this way, formation of an igneous rock resets the potassium-argon clock. The geologist simply measures the relative amounts of potassium-40 and argon-40 to date the rock.
However, there are often instances of small amounts of argon remaining in the rock when it hardens, due either to trapped atmospheric argon or from argon escaping from decays deep underground. Air argon can easily be corrected for. But the argon from underground can have a higher concentration of argon-40 escaping from the melting of older rocks. Called parentless argon-40, its parent potassium does not come from within the rock being dated, nor from the air. In these slightly unusual cases, the date given by the normal potassium-argon method is too old. However, scientists in the mid-1960s came up with a way around this problem—the argon-argon method.
Though understood for over a third of a century, groups critical of dating methods seldom discuss the argon-argon method. This method uses exactly the same parent and daughter isotopes as the potassium-argon method, in effect, presenting a different way of telling time from the same clock. More accurate than the potassium-argon method, this method is less susceptible to parentless argon. The argon-argon method can determine if a system has been disturbed. In such cases rather than giving a wrong date, the rock gives no date.2
Rubidium-Strontium. In nearly all dating methods (except potassium-argon and argon-argon), some amount of the daughter product already exists in rocks when they cool. Using these methods is like trying to tell time with an hourglass that was turned over before all of the sand had fallen to the bottom. Good techniques exist to determine precisely how much of the daughter product resided in the rock when it began to cool and harden.
In the rubidium-strontium method, rubidium-87 decays to strontium-87. Several other isotopes in strontium are stable and do not decay. The ratio of strontium-87 to one of the stable isotopes, for instance strontium-86, increases over time as more rubidium-87 turns to strontium-87. But when the rock first cools, all parts of the rock have the same ratio of strontium-87/strontium-86 because the isotopes were well mixed in the liquid magma. Some of the minerals in the rock start out with a higher ratio of rubidium to strontium than others. Rubidium has a larger atomic size than strontium, so rubidium does not fit into the crystal structure of some minerals as well as others. Figure 3 presents an important concept used in rubidium-strontium dating.
Several things can, on rare occasions, cause problems for the rubidium-strontium dating method. If a rock contains some minerals that are older than the main part of the rock, dating can be difficult. Sometimes magma inside the earth picks up unmelted minerals from the surrounding rock as it moves through a magma chamber. Usually a geologist can distinguish these "xenoliths" from the younger minerals around them. If he or she does happen to use them for dating the rock, the points represented by these minerals reveal unreliability when plotted on a graph. Other difficulties arise if a rock has undergone metamorphism, that is, if the rock became very hot, but not hot enough to completely melt (or remelt). In these cases, the dates also appear as unreliable. Some of the minerals may have completely melted, while others did not melt at all, so thus some minerals express the igneous age while others minerals express the metamorphic age. In these cases no date is determined, as the different ages within the same rock appear inconsistent.
In rare instances, the rubidium-strontium method has given straight lines that produce wrong ages. This can happen when the rock being dated was formed from magma that was not well mixed, and which contained two distinct batches of rubidium and strontium. One magma batch had rubidium and strontium compositions near the upper end of a line (such as in figure 3), and one batch had compositions near the lower end of the line. In this case, the minerals got a mixture of these two batches, and their resulting composition ended up near a line between the two batches. This is called a two-component mixing line. Only about thirty cases of this mixing line have been documented among the tens of thousands of rubidium-strontium measurements made.
If a two-component mixture is suspected, a second dating method must be used to confirm or disprove the rubidium-strontium date. The agreement of several dating methods is the most fail-safe way of dating rocks. Researchers have made comparisons of numerous dating methods on the same rocks and have shown them in close agreement, even on very old samples.3
Many dating methods work similarly to the rubidium-strontium method. Some of the more common ones include samarium-neodymium, rhenium-osmium, and lutetium-hafnium. These methods all use three-isotope diagrams similar to figure 3 to determine the age. They differ from each other primarily in the types of minerals these element pairs prefer, in the length of their half-lives, and the measuring techniques they employ.
Uranium-Lead and Related Methods. The uranium-lead method, first used in 1907, is the longest-used dating method. More complicated than other parent-daughter systems, the uranium-lead system actually puts several dating methods together. Natural uranium consists primarily of two isotopes, U-235 and U-238, and these isotopes decay with different half-lives to produce lead-207 and lead-206, respectively. In addition, lead-208 is produced by thorium-232. Three independent estimates of the age of a rock can be ascertained by measuring the lead isotopes and their parent isotopes, uranium-235, uranium-238, and thorium-232. These are often used in combination to check for concordance, or agreement, between more than one chronometer.
Extinct Radionuclides: Hourglasses That Ran Out
After the sand has run down in an hourglass, the hourglass itself offers no way to determine how long ago it finished running down. In a similar manner, finding that a once abundant radioactive parent no longer exists indicates that a longer interval of time has elapsed than the one that isotope can help to measure. In this case, the parent isotope is said to be "extinct."
A number of extinct isotopes have been identified by the measured presence of excessive amounts of the daughter isotope. These measurements show once abundant parent isotopes shortly after the creation of the solar system. Among these parents are calcium-41 (t1/2 = 130,000 years), aluminum-26 (700,000 years), iron-60 (1.5 million years), manganese-53 (3.7 million years), iodine-129 (16 million years), and plutonium-244 (82 million years). Extinct radioisotopes provide conclusive evidence that the solar system was created longer ago than the span of these half-lives. Earth was created so long ago that radioactive isotopes with half-lives shorter than half a billion years have decayed away, but not so long ago that radioactive isotopes with much longer half-lives are gone.4 This scenario is equivalent to finding the sand still falling in an hour-measuring hourglass, while the sand in an "egg-timer" hourglass has run out.
Addressing the Challenges
Radiometric dating has proven reliable from relatively short timescales of seconds, minutes, days, and years (calibrated with laboratory clocks), to a few thousand years (cross-calibrated with other reliable age indicators), to many millions of years (cross-comparison performed between dating methods). Some people question whether data from so far in the past can be credible. But trusting dating methods is similar to trusting other events of history. Why do people believe Abraham Lincoln lived? An extremely elaborate scheme would be required to fabricate his existence, including forgeries, fake photos, false quotations, and many other things. In short, to believe he existed seems far more reasonable than to believe his existence was feigned. The situation with radiometric dating is similar, only examination of rock data rather than of historical records reveals the story. Multiple corroborations of radiometric dating make a very strong case for its validity.
- Radiometric dates agree with astronomical timescales.5 In astronomy, decay rate constancy can be tested easily by studying stars at varying distances. Since these distances represent different light travel times (hence different astronomical eras), astronomers can observe whether or not decay rates were slower or faster at different eras. Their research reveals constancy, and constancy confirms established radiometric dates.
- Vast amounts of evidence for the reliability of dating have appeared in periodicals such as Science, Nature, and specific geology journals. In 1999 alone, more than a thousand papers published on radiometric dating essentially agreed on a very old age for Earth.
- Most rocks are, for practical purposes, closed systems. Some doubters have tried to dismiss geologic dating by saying that no rocks are completely closed systems (i.e., rocks are not isolated from their surroundings and as a result have lost or gained some isotopes used for dating). From an extremely technical perspective this point may be true—perhaps one atom out of a trillion has leaked out of nearly all rocks—but such a change makes an unmeasurably small change in the result. Many books written over the past forty years detail the precise conditions under which dating mechanisms work.
- The presence of only two quantities in the exponent of the equation, half-life and time, make equations for radiometric decay extremely simple. No evidence in the past century suggests that decay rates might slow down over time, leading to incorrect dates. The following argument makes such an idea meaningless in terms of "apparent" but false ages: Based on the equation, in order for ages to appear longer than actual, all half-lives would have to change in sync with each other. Since different dating methods all produce agreement, all of the half-lives must have slowed. Such an occurrence would be as if time itself slowed down.
- A misconception exists that radiometric dating is based on index fossils with dates assigned long before radioactivity was discovered. In truth, radiometric dating is based on the half-lives of radioactive isotopes measured over the last forty to eighty years. Fossils do not calibrate them. Radiometric dating is most often used on igneous rocks while fossils are found in sedimentary rocks.
- Decay rates have been directly measured over the last fifty to eighty years. In some cases, a batch of pure parent material is weighed, then set aside for a long time. The resulting daughter material can then be weighed. Often, radioactive decays can be detected more easily by the energy bursts each decay gives off. For this detection, a batch of the pure parent material is carefully weighed and then put in front of a Geiger counter (or gamma-ray detector), which counts the number of decays over a long time period.
- If decay rates were poorly known, dates could be inaccurate. However, most decay rates used for dating rocks are known to within about 2 percent accuracy. Uncertainties are only slightly higher on rhenium (5%), lutetium (3%), and beryllium (3%).6 Such small uncertainties provide no reason to dismiss radiometric dating. Whether a rock is 100 million years old or 102 million years old makes little difference.
- Since exponents are used in the dating equations, some people believe that a small error in the half-lives could lead to very large errors in the dates. In reality, a half-life off by 2 percent, leads only to a 2 percent error in the date.
- Some individuals have suggested that a small change in the nuclear forces might have accelerated nuclear clocks during a certain period just a few thousand years ago, causing spuriously old radiometric dates. Since methods date rocks from the time of their formation, such a change of nuclear forces would have to have occurred after Earth (and the rocks) were formed. To make a difference, the half-lives would require shortening from several billion years down to several thousand years—a factor of at least a million. Such a shortening would cause large physical effects. For example, Earth is heated substantially by radioactive decay. If that decay is sped up by a factor of a million or so, the tremendous heat pulse would easily melt the whole planet, including the rocks in question.
- Some people suggest that the "full-life" (the time at which all of the parent is gone) should be measured rather than the half-life (the time when half of it is gone). Unlike sand in an hourglass, which drops at a constant rate independent of how much is remaining, the number of radioactive decays is proportional to the amount of parent remaining. Figure 2 shows how after two half-lives, ½ x ½ = ¼ is left, and so on. After 10 half-lives there is 2-10 = 0.098% remaining. Scientists sometimes instead use the term "mean life," that is, the average life of a parent atom. The mean life is always 1/ln(2) = 1.44 times the half-life. Most people more easily understand half-life.
- Subjecting rocks used in dating methods to heat, cold, pressure, vacuum, acceleration, and strong chemical reactions that could be experienced on Earth or other planets yields no significant change in radioactive decay rates.
- Claims of unreliability have been made based on the inaccurate dating of a rock from the Mount Saint Helens eruption (1980). The dating lab reported it as several million years old. Does this mean radiometric dating can't be trusted? Not when proper procedures are observed. Radiometric dating can be "tricked" if a single dating method is improperly used on a sample. Anyone can move the hands on a clock to indicate the time incorrectly. Likewise, people actively looking for incorrect radiometric dates can find them. However, multiple dating methods used together on igneous rocks are typically trustworthy.
Some people propose that since radiogenic helium and argon continue to escape from Earth's interior, Earth must be young. However, the radioactive parent isotopes, uranium and potassium, have very long half-lives, as shown in Table 1. These parents still exist and still produce helium and argon in abundance in Earth's interior. Further, a time lag exists between the production of daughter products and their escape (or degassing). If Earth were geologically young, very little helium and argon would have been produced by now. What does the evidence show? Researchers have compared the amount of argon in the atmosphere to the amount expected from decay of potassium over 4.6 billion years, and they find consistency.
- Unsubstantiated speculation can produce the idea that only nontheists and others who dismiss the inerrancy of the Bible give credence to radiometric dating techniques. However, the roots of the scientific age can be traced to the idea that God's creation is testable, trustable, and worthy of systematic study. The key concept of such study details God's revelation of Himself, not only through the Bible (special revelation) but also through creation (general revelation). A great number of other Christians recognize with conviction that radiometric dating substantiates evidence that God created Earth billions, not thousands, of years ago. Many Christians work in the field of radiometric dating.
God's Word Validates Scientific Conclusions
Accepting the reliability of radiometric dating cannot be considered equivalent to compromising the spiritual and historical inerrancy of God's word. Many Christians view a proper reading of Genesis 1 to indicate that "day" refers literally to a long period of time.
The psalmist marveled at the scope of God's creation. Today, the length and breadth of God's creation, both in temporal and spatial dimensions, speak ever more clearly of the Creator's awesome nature. The heavens do declare the Lord's glory, and the Earth indeed shows God's handiwork. Radiometric dating testifies to the magnificence of God's power. Careful consideration of all the scientific facts and all the relevant Scripture passages can help people like Janet discern both the age of Earth and the validity of the biblical creation account. Together science and Scripture provide the answer Janet needs for herself—and for her son.
Roger C. Wiens wrote his Ph.D. dissertation on isotope ratios in meteorites. He worked for ten years in the geology departments at Caltech and the University of California, San Diego, characterizing oceanic rocks and isotope ratios in diamonds, and studying the feasibility of a space mission for NASA. He presently works in the Space and Atmospheric Sciences Department of the Los Alamos National Laboratory. He has published over 20 scientific research papers and has also published articles in Christian magazines. Dr. Wiens has been a member of Mennonite, Baptist, and Conservative Congregational churches.
- Atom: The smallest unit that materials can be divided into. An atom is about ten billionths of an inch in diameter and consists of a nucleus of nucleons (protons and neutrons) surrounded by electrons.
- Closed system: A system (rock, planet, etc.) that has no influence or exchange with the outside world. In reality there is always some exchange or influence, but if this amount is completely insignificant for the process under consideration (e.g., for dating, if the loss or gain of atoms is insignificant) for practical purposes the system can be considered closed.
- Daughter: The element or isotope that is produced by radioactive decay.
- Decay: The change from one element or isotope to another. Only certain isotopes decay. The rest are said to be stable.
- Element: A substance that has a certain number of protons in the nucleus and unique properties. Elements may be further broken down into isotopes, which have nearly all of the same properties except for their mass and their radioactive decay characteristics.
- Half-life: The amount of time it takes for half the atoms of a radioactive isotope to decay.
- Igneous rock: Rock formed from molten lava. The other two types of rock are sedimentary (formed by the cementing together of soil or sand) and metamorphic (rocks re-formed by heat over long periods of time).
- Isotope: Atoms of a given element that have the same atomic number. Most elements have more than one isotope. Most radioactive elements used for dating have one radioactive isotope and at least one stable isotope. For example carbon-14 (which weighs 14 atomic mass units) is radioactive, while the more common isotopes, carbon-12 and carbon-13 are not.
- Magma: Hot molten material from which rocks are formed. When magma erupts on the surface of the earth it is called lava.
- Metamorphism: The heating of rocks over long time periods at temperatures which are hot enough to change the crystal structure but not hot enough to completely melt the rock. Metamorphism tends to alter or reset the radiometric time clocks, though some radiometric techniques are more resistant to resetting than others.
- Nucleons: Neutrons and protons, which make up the nucleus of an atom.
- Parent: The element or isotope which decays. The element it produces is called the daughter.
- Radioactive: Subject to change from one element to another. During the change, or decay, energy is released either in the form of light or energetic particles.
- Radiocarbon: Carbon-14, which is used to date dead plant and animal matter. Radiocarbon is not used for dating rocks.
- Radiometric dating: Determination of a time interval (e.g., the time since formation of a rock) by means of the radioactive decay of its material. Radiometric dating is one subset of the many dating methods used in geology.
- Three-isotope plot: In dating, this is a plot in which one axis represents the parent isotope and the other axis represents the daughter isotope. Both parent and daughter isotopes are ratioed to a daughter element isotope that is not produced by radioactive decay. This type of plot gives the age independent of the original amounts of the isotopes.
- Two-component mixing: The mixing of two different source materials to produce a rock. On rare occasions this can result in an incorrect age for certain techniques that use three-isotope plots. Two-component mixing can be recognized if more than one dating technique is used, or if surrounding rocks are dated.
- Xenolith: Literally, a foreign chunk of rock within a rock. Some rocks contain pieces of older rocks within them. These pieces were ripped off of the magma chamber in which the main rock formed and were incorporated into the rock without melting. Xenoliths do not occur in most rocks, and they are usually recognizable by eye where they do occur. If unrecognized, they can result in an incorrect date for a rock (the date may be of the older xenolith).
- Norman E. Holden, "Total Half-Lives for Selected Nuclides," Pure Applied Chemistry 62 (1990), 941-58. See also geochronology textbooks such as Alan P. Dickin, Radiogenic Isotope Geology (New York: Cambridge Press, 1995); Gunter Faure, Principles of Isotope Geology, 2d ed. (New York: Wiley, 1986).
- 2. Roger C. Wiens, Radiometric Dating: A Christian Perspective, available from ASA Web site (1995) http://www.asa3.org/ASA/resources/Wiens.html; Internet; accessed 8/01/01. See also geochronology textbooks such as those by Dickin; Faure.
- Wiens; G. Brent Dalrymple, The Age of the Earth (Stanford, CA: Stanford University Press, 1991).
- Some isotopes with half-lives shorter than several hundred million years exist, but only because they are constantly being replenished by either cosmic rays (a special case, e.g., the three lowest entries in Table 1) or because they themselves are daughters of some longer-lived parent such as uranium.
- Hugh Ross, Creation and Time, (Colorado Springs, CO: NavPress, 1994).
- Holden, 941-58; see also geochronology textbooks such as Dickin; Faure.
Half lives taken from Holden, 941-58; see also geochronology textbooks such as Dickin; Faure.
Figure Captions
Table I.
Parent-daughter pairs and half-lives for some of the most commonly used radiometric dating methods.7
Decay Product
|106 billion
|48.8 billion
|42 billion
|38 billion
|14 billion
|4.5 billion
|1.26 billion
|0.7 billion
|1.52 million
Sidebar: Atoms, Isotopes, and Radioactive Decay
By Fazale Rana, Ph.D.
Atoms, the smallest, chemically distinct units of matter, are roughly 0.1 to 0.2 nm in size (one nanometer is one-billionth of a meter). Three elementary particles make up atoms. Two of them, protons and neutrons, interact to form the atom's nucleus. A cloud of electrons surrounds the nucleus. Essentially all of an atom's volume comes from its electron cloud, whereas nearly all of the atom's weight resides in the protons and neutrons in its nucleus.
Protons possess a unit positive charge, while neutrons contain no charge. This renders the nucleus with a positive charge equal to the number of protons resident in the nucleus. Electrons possess a negative charge. For an atom to maintain electrical neutrality, the number of its electrons must equal the number of its protons.
The number and arrangement of electrons surrounding the nucleus determines the atom's chemistry. Since the electronic structure of an atom depends on the number of its protons, that proton number (atomic number) defines the atom. Any atom with 19 protons, for example, is a potassium atom; any atom with 37 protons is a rubidium atom, and any atom with 38 protons is a strontium atom. The number of protons and neutrons determines the atom's mass (atomic mass).
While the proton number must remain fixed for a particular type of atom, the number of neutrons may vary. Variation in neutron number does not change the chemistry of the atom, but does change the atomic weight. For example, potassium-39 has 19 protons and 20 neutrons; potassium-40 has 19 protons and 21 neutrons. Both potassium-39 and potassium-40 display identical chemical properties, since they both have 19 protons. Potassium-40 weighs more than potassium-39 by 1 atomic mass unit (amu), since it has one more neutron in its nucleus than potassium-39.
Atoms with the identical number of protons but possessing a differing number of neutrons are called isotopes. Potassium-39 and potassium-40 are both isotopes of potassium.
Certain proton and neutron number combinations are unstable. When this instability occurs, the nucleus breaks down through the process of radioactive decay to a stable combination of protons and neutrons. In this decay process, the (parent) atom's nucleus either gains or loses protons. This results in the formation of a new (daughter) atom. For example, potassium-40's nucleus is unstable. As a result, the potassium-40 nucleus picks up an electron from the surrounding electron cloud. This electron combines with a proton to form a neutron. The resulting nucleus gains a neutron and loses a proton. Since the total number of protons plus neutrons defines the atom's mass, the atomic mass remains unchanged, but the atomic number decreases by one. The newly formed daughter atom possesses 18 protons, 18 electrons and 22 neutrons. Any atom with 18 protons is an argon atom. This transformation, or "radioactive decay'" process, alters the chemical properties of the parent potassium atom producing a daughter atom of argon, a gas.
Exotic Life Sites: The Feasibility of Far-Out Habitats
By Hugh Ross
People often joke about the certainty of death and taxes. Astronomers can add another certainty to that short list: Sooner or later someone will ask, "What do you think about the possibility of life out there?"
Most questioners are looking for a particular answer. Science fiction novels, The Planetary Society, and countless movies, from E.T. to Contact to Planet of the Apes, suggest that extraterrestrial life is a given and help conjure images of how that life looks. To answer questions about such life takes as much diplomacy as answering my wife when she asks, "How do I look?"
Experience suggests a strategy for handling both questions. Step one: Make a positive statement, such as "You look great!" or "That's a great question!" Step two: Provide amplification. This part is trickier. It can make or break the interaction. If it lacks sincerity or includes the word but, (e.g., "You look great, but I thought you were going to wear the blue dress"), my wife may walk away feeling hurt and deflated. A better answer adds some specific feedback (e.g., "You look great, and I especially like the way that color goes with your eyes").
In the case of the life-elsewhere question, an honest, fact-based amplification acknowledges the "great question" as opening the door to three fascinating topics: life on other planets, life on other astronomical bodies, and life other than "life as we know it." Step-by-step discussion of these subjects can lead to opportunities for spiritually significant conversation.
Life on Other Planets
Technology and interdisciplinary research have enabled scientists to develop an extensive list of physical characteristics that must fall within limited ranges for a planet (or any other astronomical body) to be capable of life support. Those characteristics involve the planet's star, moon(s), planetary companions, and galaxy, as well as the planet's surface, interior, and atmospheric conditions. This list grows longer with every year. It started with two parameters in 1966,1 grew to eight by 1970, to twenty-three by 1980, to thirty by 1990, and to forty by 1995.2 Currently, the list includes more than 120 parameters and shows no signs of leveling off.3
The limits on some characteristics, especially on the essential-to-life features of a planet's star, have been determined precisely. The limits on others, mostly on the features of the planet itself, presumably a terrestrial (rocky) planet, are less precisely known. Two reasons exist for this difference: First, trillions of stars are available for study while only 76 planets (9 in Earth's solar system, 67 outside) have been discovered to date. Second, physical and chemical characteristics make stars, basically condensed balls of hot gas, much simpler systems than planets.
No one knows, of course, exactly how many planets exist. As recently as 1990, astronomers were divided between those who proposed that planets whirl around nearly every star and those who posited that the Sun alone possesses planets. Three research advances tilt the debate toward the latter scenario: (1) the availability of instruments and techniques capable of detecting and studying planets orbiting other stars; (2) the discovery that most, if not all, stars surrounded by disks of dust are young or still forming; and (3) the development of sophisticated theoretical models that explain how dust disks become planets.
Each of the 67 extrasolar planets discovered and studied to date orbits a relatively young, metal-rich star (a star rich in elements heavier than hydrogen and helium).4-8 This finding presents no surprise. The heavy elements needed to make planets and any type of life chemistry do not exist in sufficient quantity until at least two generations of stars have formed, burned out, and scattered their ashes, which then recycle to form more stars. Astronomers have learned that the longer a galaxy sustains star formation, the more metal rich its newly forming stars will be. In the case of the galaxy astronomers know best, the Milky Way galaxy (Earth's own), only 2 percent of the stars possess metal richness adequate for planet formation.9
Of those Milky Way stars known to have planets, none formed as early as the Sun. The Sun benefited from a remarkable set of circumstances: it formed adjacent to two massive, star explosions (supernovae), each of which spewed out a different set of life-essential heavy elements.10-12 Those explosions occurred precisely at the right time and place for those heavy elements to be incorporated into the condensing solar nebula. Earth's star may be the only star its age with an ensemble of both small rocky planets and gas giants. This finding implies that the probable number of life-site candidates falls far below 2 percent.
As for life-support planets in other galaxies, the odds look bleak. Astronomers have found that the Milky Way is exceptional for the longevity of its star formation processes. In 94 of every 100 galaxies, star formation shut down so long ago that few, if any, metal-rich stars reside there—hence few, if any, planets. The results of a Hubble Space Telescope (HST) study recently confirmed this conclusion. The HST searched for planets in an enormous cluster of old stars, 47 Tucanae, and found none.13
Observations indicate that the number of stars with planets, any kind or size of planets, adds up to only about 0.1 percent of all the stars in the cosmos. That number is at least a hundred times smaller than the estimate that launched the search for signals from extraterrestrial life.14 Small though that percentage may be, however, it still adds up to a lot of planets. If, for example, each star in that 0.1-percent group has ten planets around it, the number of planets would add up to a hundred million trillion (that is, 1020).
A hundred million trillion, then, is the number to which the data on various life-essential features must be applied. Some features fall within loose limits—others, within strict limits. Limits on the planet's rotation period and its albedo (reflectivity) eliminate about 90 percent of the life-site candidates. Parameters such as the parent star's mass and the planet's distance from its parent star eliminate about 99.9 percent of all relevant candidates.
Dependency factors among certain of the parameters improve the odds somewhat, but many of these parameters must be kept within a specific range for long periods of time. Given how variable environments can be, this longevity requirement proves extremely limiting. The data demonstrate that the probability of finding even one planet with the capacity to support life falls short of one chance in 10140 (that number is 1 followed by 140 zeros).15
Life on Alternative Sites
The extreme improbability such a number indicates has driven some scientists to abandon the premise that life requires an Earth-like home. A satellite (moon) orbiting a giant planet that in turn orbits a star resembling Earth's sun at the right distance could serve, they say, as a life site.16-18 The feasibility of such an alternative can be tested against a long list of recent findings.
None of the 67 "gas giant" planets found thus far outside Earth's solar system orbit their stars in the zone life requires. Gas giants, which are many times larger than Earth, form under cold, low radiation conditions far from their stars. By gravitational interactions with interplanetary dust or with other planets and stars that pass by, most gas giants drift into the proximity of their stars. This drifting process drastically decreases their likelihood of retaining the nearly circular, stable orbit life demands.19-24 Of the known extrasolar gas giants, only two orbit anywhere near the life-habitable zone, and these two follow such an eccentric (i.e., elongated) orbital path as to make life on their satellites (moons), if they have any, impossible.25-28 The question remains unanswered as to whether or not giant planets can possibly retain the satellites during migration.
A satellite close enough to its planet to avoid enormous seasonal temperature fluctuations (caused by variations in the distance to the planet's star, or heat source, as the satellite orbits its planet) becomes tidally locked to the planet—the same side always faces the planet. This tidal locking itself causes a host of life-destructive effects.
For example, tidal locking makes the satellite's rotation period identical to the planet's. Unless that period is short enough, day-to-night temperature differences become too extreme for life's survival. However, the rotation period can only be that short if the satellite orbits closely. Within this sufficiently close range, however, another set of problems arises. For example, tidal forces generate drastic climatic and orbital instabilities (tidal torques force such a satellite to move farther and farther away from its planet), as well as massive and frequent volcanic eruptions (such as astronomers see on Jupiter's moon Io).29 Any possible life-favorable conditions last briefly, at best.
A satellite with a highly improbable life-sustaining atmosphere most likely loses it in short order unless that satellite somehow possesses a strong magnetic field (similar to that of the Sun, Jupiter, and Earth). Otherwise, charged particles accelerated by the planet's magnetosphere sputter away the satellite's atmosphere. The magnetic field around Ganymede, the largest known planetary satellite and the only one with undisputed magnetism, measures less than 1 percent the strength of Earth's.30-32
Another life risk for a satellite closely orbiting a large planet is that such a planet's gravity significantly attracts asteroids, comets, and other debris passing nearby. This attraction increases the likelihood of bombardment, and such bombardment proves catastrophic to any possible life on the satellite.
A satellite cannot retain an adequate atmosphere for life unless its mass exceeds 12 percent of Earth's mass. 33 At the same time, the satellite needs a mechanism to compensate for its nearby star's increasing luminosity (brightness, thus light and heat radiation) as the star ages. The only known mechanism is the one seen on Earth, called the carbonate-silicate cycle. This cycle cannot operate, however, without lots of dry land (which eliminates ice-water environments such as Jupiter's satellite Europa) and without a high level of plate tectonic activity.34, 35
Plate tectonics, in turn, require a certain minimum mass (0.23 Earth masses), and the demands of sustaining a carbonate-silicate cycle significantly increases that minimum. The best calculation to date sets the minimum mass of this hypothetical satellite at three times the mass of Mars, which is more than twelve times the mass of the solar system's largest satellite. Of course plate tectonics also demand lots of liquid water (thus eliminating all dry satellites) and the precisely-timed introduction of just-right plant life in just-right amounts throughout the satellite's history.36-37
More Radical Proposals
Sustaining the quest for other potential life sites, planetary scientist David Stevenson and origin-of-life researchers Jeffrey Bada and Christopher Wills go so far as to speculate that life might not require a home near a star.38-39 They suggest this scenario: A planet may be ejected from a normal planetary system before losing any of its light gases. If so, the planet may retain enough surface warmth (from interior radioactive decay) and a sufficiently heavy molecular hydrogen outer atmosphere (a heat-trapping blanket) to sustain life chemistry and metabolism.
To be capable of life support, however, such a hypothetical site would require super-enrichment by radioactive elements, and no mechanism or scenario exists to bring this enrichment about—none that would accomplish the job without simultaneously destroying the molecular hydrogen outer atmosphere. If the planet somehow acquired this enrichment, it still faces a problem: heat from the radioactive decay would decline exponentially through time. So, while such a planet might serve as a brief stopover for primitive life, it could not stay within the life-support range of temperature and other conditions long enough to serve as any conceivable home for intelligent life.
If life claims a home anywhere in the vast cosmos, it must be on a planet like Earth orbiting a star like the Sun in a galaxy like the Milky Way. And, as ongoing studies shows, that possibility shrinks, rather than grows, as each year's research adds to the harvest of data. Extraterrestrial life does indeed appear to be homeless—unless, of course, a transcendent, supernatural Being built that home. But that possibility points toward, rather than away from, belief in the biblical Creator.
Alternative Life Forms
One other possibility must still be addressed, a question that often hampers progress toward a realistic assessment of the chance for life elsewhere: To what degree might extraterrestrial life differ from "life as we know it"? At one time biologists speculated that extraterrestrial life might be based on exotic chemistry, something other than carbon.
So, biochemists went to work on the problem. Their research showed that only silicon and boron, besides carbon, can serve as the basis for adequately complex molecules—molecules capable of sustaining basic life functions, such as self-replication, metabolism, and information storage. This finding presents some significant problems, however. First, silicon can hold together a string of no more than a hundred amino acids—far too short a string to accommodate any conceivable life systems and processes. Second, throughout the universe boron is less abundant than carbon; so carbon always supersedes it. Third, concentrated boron is toxic to certain life-critical reactions.
The conclusion, published as early as 1961, still stands. Physicist Robert Dicke deduced at that time that if anyone wants physicists (or any other physical life forms, for that matter), carbon-based biochemistry is a must.40 The key word, here, is physical. What about life that is not physical?
The Spiritual Opportunity
Both science and the Bible offer helpful information on this topic of non-physical reality. Science points to the existence of a transcendent (beyond space and time), personal Creator, demonstrably the same Creator revealed in the pages of Scripture. The Bible, in turn, reveals the existence of life forms other than Earth life, other than physical life. This life may be described as spiritual life, and yet it possesses the capacity for at least some physical expression or manifestation.
The Bible calls these creatures (in English translations) "angels," "ministering servants," or "ministering spirits." Three specific names are given in the text: Michael, Gabriel, and Lucifer. The latter, also called Satan, led a rebellion against God. Scripture refers to the angels who rebelled with him (about a third of the total number) as "evil spirits," "devils," or "demons." The one reliable source of information about this other kind of life is the Bible, and further study is highly recommended.
The possibility for life elsewhere is in fact great, as great as the certainty that the Bible is a true, trustworthy, and relevant revelation from the Creator. Any question that leads to an opportunity to talk about the word of God as well as the work of God, the Creator, deserves to be called a great question.
- Iosef S. Shklovskii and Carl Sagan, Intelligent Life in the Universe (San Francisco: Holden-Day, 1966), 343-52.
- Hugh Ross, The Creator and the Cosmos, 2d ed. (Colorado Springs, CO: NavPress, 1995), 132-44.
- Hugh Ross, The Creator and the Cosmos, 3d ed. (Colorado Springs, CO: NavPress, 2001), 195-99.
- Guillermo Gonzalez, "The Stellar Metallicity-Giant Planet Connection," Monthly Notices of the Royal Astronomical Society 285 (1997): 403-12.
- Guillermo Gonzalez, "Spectroscopic Analysis of the Parent Stars of Extrasolar Planetary System Candidates," Astronomy and Astrophysics 334 (1998): 221-38.
- Guillermo Gonzalez, George Wallerstein, and Steven H. Saar, "Parent Stars of Extrasolar Planets. IV. 14 Herculis, HD 187123, and HD 210277," Astrophysical Journal Letters 511 (1999): L111-14.
- Guillermo Gonzalez and Chris Laws, "Parent Stars of Extrasolar Planets. V. HD 75289," Astronomical Journal 119 (2000): 390-96.
- Guillermo Gonzalez et al., "Parent Stars of Extrasolar Planets. VI. Abundance Analyses of 20 New Systems," Astronomical Journal 121 (2001): 432-52.
- Guillermo Gonzalez, private communication, 1991. The 2 percent figure was determined from the minimum metal richness observed in stars with planets and the maximum age of stars with planets. Interestingly, Carl Sagan came up with the same figure in 1966 (Shklovskii and Sagan, 344).
- S. Sahipal et al., "A Stellar Origin for the Short-Lived Nuclides in the Early Solar System," Nature 391 (1998), 559-661.
- G. J. Wasserburg, R. Gallino, and M. Busso, "A Test of the Supernova Trigger Hypothesis with 60Fe and 26Al," Astrophysical Journal Letters 500 (1998): L189-93.
- Peter Hoppe et al., "Type II Supernova Matter in a Silicon Carbide Grain from the Murchison Meteorite," Science 272 (1996): 1314-16.
- Ronald L. Gilliland et al., "A Lack of Planets in 47 Tucanae from a Hubble Space Telescope Search," Astrophysical Journal Letters 545 (2000): L47-51.
- Shklovskii and Sagan, 343-50.
- Ross, The Creator and the Cosmos, 3d, 187-99.
- J. F. Kasting, D. P. Whitmire, and R. T. Reynolds, "Habitable Zones around Main Sequence Stars," Icarus 101 (1993): 108-28.
- Darren M. Williams, James F. Kasting, and Richard Wade, "Habitable Moons around Extrasolar Giant Planets," Nature 385 (January 1997), 234-36.
- Darren M. Williams, "Habitable Moons around Extrasolar Giant Planets," in The Stability of Habitable Planetary Environments (Ph.D. thesis, Pennsylvania State University, 1998), 111-20.
- Frederic A. Rasio and Eric B. Ford, "Dynamical Instabilities and the Formation of Extrasolar Planetary Systems," Science 274 (November 1996): 954-58.
- N. Murray, B. Hansen, M. Holman, and S. Tremaine, "Migrating Planets," Science 279 (January 1998): 69-72.
- D. N. C. Lin, P. Bodenheimer, and D. C. Richardson, "Orbital Migration of the Planetary Companion of 51 Pegasi to Its Present Location," Nature 380 (April 1996), 606-7.
- Stuart J. Widenschilling and Francesco Marsari, "Gravitational Scattering as a Possible Origin for Giant Planets at Small Stellar Distances," Nature 384 (December 1996), 619-21.
- Stuart Ross Taylor, Destiny or Chance: Our Solar System and Its Place in the Cosmos (Cambridge, UK: Cambridge University Press, 1998).
- Jean Schneider, Extra Solar Planets Catalog www.obspm.fr/encycl/catalog.html.
- S. Vogt et al., "Six New Planets from the Keck Precision Velocity Survey," Astrophysical Journal 536 (2000): 902-14.
- Gozalez, Wallerstein, and Saar, L111-14.
- Ing-Guey Jiang and Wing-Huen Ip, "The Planetary System of Upsilon Andromedae," Astronomy and Astrophysics 367 (2001): 943-48.
- Jean Schneider, Extra Solar Planets Catalog. wwwusr.obspm.fr/departement/darc/planets/encycl.html.
- William B. McKinnon, "Galileo at Jupiter—Meetings with Remarkable Moons," Nature 391 (1997), 23-26.
- Guillermo Gonzalez, "New Planets Hurt Chances for ETI," Facts & Faith 12, no. 4 (1998), 2-4.
- D. A. Gurnett et al., "Evidence for a Magnetosphere at Ganymede from Plasma-wave Observations by the Galileo Spacecraft," Nature 384 (December 1996), 535-37.
- M. G. Kivelson et al., "Discovery of Ganymede's Magnetic Field by the Galileo Spacecraft," Nature 384 (December 1996), 537-41.
- Kivelson et al., 541.
- Hugh Ross, The Creator and the Cosmos, 3d ed. (Colorado Springs, CO: NavPress, 2001), 180-83.
- Darren M. Williams, thesis, 115-17.
- Katherine L. Moulton and Robert A. Berner, "Quantification of the Effect of Plants on Weathering: Studies in Iceland," Geology 26 (October, 1998): 895-98.
- Tyler Volk and David Schwartzman, "Biotic Enhancement of Weathering and the Habitability of Earth," Nature 340 (1989), 457-60.
- David Stevenson, "Life-Sustaining Planets in Interstellar Space?" Nature 400 (1999), 32.
- Christopher Wills and Jeffrey Bada, The Spark of Life (Cambridge, MA: Perseus Publishing, 2000), 250-52.
- Robert H. Dicke, "Dirac's Cosmology and Mach's Principle," Nature 192 (1961), 440.
The Leap to Two Feet: The Sudden Appearance of Bipedalism
By Fazale R. Rana
Did man crawl his way into existence over millions of years? Or did he leap to two feet by supernatural design? Did humans emerge from amoebas or did a Creator intend for life to possess purpose, value, and meaning? Answers to such questions mightily impact how human societies respond to their most pressing problems. A divinely-designed, sentient, spiritual creature deserves greater care and consideration than does a random fluke of nature.
Some scientists say that human beings are a mere quirk of fate—intelligent apes produced by chance events taking place over the last 5 million years. They claim natural selection played a role in the process that led to modern humans. Competitive, predatory, and environmental pressures gradually selected inheritable changes, they say. These changes supposedly imparted increased survivability and reproductive success. Thus, natural selection would have operated on random variation again and again, producing a succession of new species until finally by chance modern humans came to be.
Along with large brain size (actually, brain size-to-body mass ratio), manual dexterity, and advanced culture, bipedalism constitutes one of the most important defining characteristics of humans. For evolutionary anthropologists, understanding the emergence and development of bipedalism equates with understanding the origin of humanity.
In sharp contrast to evolutionary thinking, the Bible reveals human beings as the pinnacle of God's creative activity, made in His image and distinct from all other creatures.1 Biblical accounts of man's beginnings leave no room for God's using an ape-to-human evolutionary transformation process to create man. Scripture describes God's direct involvement in creating the first humans, physical and spiritual creatures of immense worth from the time of their inception.
With its focus on testability,2 a powerful new approach helps discriminate between the biblical and evolutionary explanations for the origin of humanity (see sidebars). Predictions made by these origin models can be subjected to the rigors of scientific testing. The one with the greatest support from the scientific record and with predictions that best accommodate new discoveries exemplifies the most accurate scenario.
Recent advances in paleoanthropology (the study of the bipedal primate fossil record) and the paleoecology (study of ancient ecologies) associated with bipedalism present an unusual opportunity to make data comparisons. New discoveries in these, as well as other disciplines, argue against a naturalistic origin to bipedalism and provide substantial affirmation for the biblical record.
Evolutionary Scenarios
According to the evolutionary paradigm, since an ape-like ancestor gave rise to both the ape and the human lineages, bipedal primates must have evolved from knuckle-walking quadrupeds. Knuckle-walking exists as a special type of terrestrial quadrupedalism (ground-based locomotion employing all four limbs) possessed by chimpanzees and gorillas.3 Knuckle-walkers rest their weight on their knuckles, not on their palms or fingers. This design allows chimpanzees and gorillas to walk on all four limbs while still having the dexterity of long curved fingers for climbing and swinging through trees.
Paleoanthropologists propose a myriad of hypotheses to explain how bipedalism could arise from natural processes. One early explanation suggests bipedalism emerged to free the hands for tool use. Since the fossil record contradicts this notion, evolutionary biologists have rejected this idea. The archeological record clearly shows the existence of bipedalism at least 2 million years before tool use appeared.4
Most hypotheses seeking to account for bipedalism's emergence depend on East Africa's transformation from a woodland and forest environment to an arid, open savanna.5 With such changes, terrestrial quadrupeds faced reduced food supplies, increased risk of falling prey to predators, and the inability to avoid direct sunlight.6
Bipedalism offers a way to address these challenges. Walking erect served as a more energy efficient means of locomotion at slow speeds.7 This allowed bipedal primates to traverse long distances foraging for food. Once having found food, bipedal primates could carry the foraged food long distances as they returned to their "home-base" to provide for their young.8
By the height of their heads, bipedal primates are more effective at avoiding predation in an open savanna than quadrupedal apes. Standing erect would allow these animals to detect predators sooner and from greater distances.
Bipedalism also offers a thermoregulatory advantage.9 A bipedal primate standing upright absorbs 60 percent less heat than does an ape walking on all four limbs. A quadrupedal stance exposes the entire back to direct sunlight, whereas standing erect exposes only the head and shoulders.
Evolutionary biologists have yet to reach a consensus on the selective pressures that could have produced bipedalism in primates, nor have they demonstrated a mechanism that can bring about such dramatic changes in the time permitted (see the following section). To date, the only reasonable source of evolutionary pressure behind the four-to-two transformation remains the loss of a woodland habitat throughout East Africa.
Anatomy of Bipedalism
To transition from a knuckle-walking quadruped to an upright biped involves extensive anatomical changes.10 These changes include the following:
- Relocation of the spinal cord opening
The foramen magnum (the opening in the base of the skull that receives the spinal cord) must be relocated from the back to the center of the skull base. In this position the vertebral column effectively balances the head, eliminating the need for powerful neck muscles.
- Restructuring of the inner ear bones
The inner ear bones, which play a role in balance, must be altered to support bipedalism.
- Introduction of spinal curvature
The lower and upper vertebral column must possess forward curvature to maintain bipedalism. This forward curvature coupled with the backward curvature in the middle of the spinal column allows the backbone to function as a spring, facilitating movement.
- Restructuring of the rib cage
Apes' inverted funnel-shaped rib cage accommodates arm use for locomotion. The barrel-shaped rib cage of bipeds permits effective use of the arms for nonlocomotory functions.
- Reshaping the pelvis
To accommodate the hip joints and muscles necessary for bipedalism, the pelvis of bipedal primates must be lower and broader than that of knuckle-walking apes.
- Altered lower limbs
Bipedal primates not only have longer lower limbs than quadrupeds, the valgus angle (the angle that the femur makes with the midline of the body) is also different. Longer lower limbs shift the center of mass towards the lower body. Angling the femurs inward moves the center of mass closer to the midline of the body. The altered center of mass allows stable bipedal locomotion.
- Enlarged joint surfaces
Not only does the knee need to be restructured to accommodate the changed valgus angle, but joint surfaces must also be enlarged. This enlargement increases the contact area, helping the knee and other joints withstand the stress of standing or walking upright.
- Restructured foot
Even the feet must be structured differently to support bipedalism. A platform foot with an arch allows for a greater surface area, one that can better withstand shock. In bipedal primates, the big toe is more elongated and aligned with the other toes and, thus, needs a different location. This new placement allows the toe to make the last point of contact with the ground as the leg swings forward during a bipedal stride.
- Restructuring of the body's musculature
In order to accommodate the extensive skeletal changes required by the transition from a quadruped to a biped, much of the musculature must also be altered.
The dramatic anatomical changes that must occur to transform knuckle-walking quadrupeds to bipedal primates thwart efforts to envision how this transformation could take place. Nevertheless, if bipedalism did emerge through natural-process biological evolution, it should occur gradually and appear well after the time that apes and humans are supposed to have diverged. Moreover, the first form of bipedalism to appear should be crude and inefficient. Once appearing, it should gradually transition to the more efficient obligatory bipedalism of modern humans. Lastly, significant evolutionary pressure would be necessary to force knuckle-walking apes, perfectly suited for their environment and lifestyle, to change into upright walking primates, if such change actually could occur.
Recent Scientific Advances
Several recent discoveries from the fossil and geological records have radically transformed paleoanthropologists' view of the origin and natural history of bipedalism. These new scientific advances sharply contradict predictions stemming from evolutionary scenarios.
Bipedalism's First Appearance
In 1994 and 1995 paleoanthropologists reported two sets of discoveries that described the fossil remains of two species of australopithecines. One research team uncovered the remains of a hominid in Ethiopia dated at 4.4 million years in age.11 This specimen they named Australopithecus ramidus, though it was later reassigned to a new genus, Ardipithecus.12
Meanwhile, another team of researchers discovered a set of hominid fossils in Kenya determined to be between 3.9 and 4.2 million years in age.13 These specimens were attributed to a newly recognized australopithecine species, Australopithecus anamensis. A follow-up discovery confirmed the date for this species at 4.07 million years ago.14 Analysis of an A. anamensis tibia clearly established its bipedal capacity, pushing the appearance of bipedalism back by at least a half a million years. Prior to this discovery the oldest primate with bipedal capabilities was believed to be Australopithecus afarensis (~3.9 million years ago).
It is still not clear if Ardipithecus ramidus possessed bipedal capabilities. If so, bipedalism's first appearance occurs very close to the time that the ape and human lineages supposedly split. This allows the forces of natural selection only a few hundred thousand years to generate bipedalism—a time period far too short, according to evolutionary biologists, given the extensive anatomical changes necessary for a quadrupedalism-to-bipedalism transition.
If A. ramidus lacked bipedal capabilities, this too creates problems for the evolutionary paradigm. Evolutionary biologists view A. ramidus as the ancestral species that gave rise to A. anamensis. In this scenario, bipedalism must have emerged in less than two hundred thousand years—an even shorter (hence less feasible) time period for the enormous species' differentiation to occur.
Paleoecology of Bipedalism
Recent work characterizing the environment in which the oldest bipedal primates lived yielded unexpected results. A. ramidus and A. anamensis did not live in open savannas, but rather in woodlands and forests.15 Moreover, recent studies indicate that A. afarensis lived in a mix of woodland and open savanna environments.16
A newly discovered australopithecine species, Australopithecus bahrelghazali, recovered in Chad and dated to be between 3.0 and 3.5 million years in age also lived in a mixed habitat.17 And the newly discovered hominid specimen, Kenyanthropus platyops, dated at 3.5 million years in age, lived in a predominantly woodland and forest environment that included open grasslands.18
In the words of anthropologist and science writer Roger Lewin, "The popular notion of our forebears striding out of dense forest onto grassland savanna is likely to be more fiction than fact."19 This new recognition, expressed by Lewin, creates profound trouble for the evolutionary paradigm, eliminating the evolutionary driving force long predicted to have generated bipedalism.
A recent geological study conducted to understand the aridification of East Africa—the event that caused a transformation of its woodlands into an open savanna—provides further evidence that the loss of a woodland environment could not have been the driving force in the emergence of bipedalism. This study indicates that the closure of the Indonesian seaway 3-4 million years ago led to reduced rainfall in East Africa and eventually to the transition from woodlands to grasslands.20 By the time East Africa became arid, bipedalism had already appeared.
Static Bipedalism
A recent mathematical and statistical analysis of over two hundred pelvic bone specimens from apes, extinct hominids, and modern humans uncovered a historical pattern that challenges the evolutionary explanation of bipedalism at its core.21 Instead of gradually changing over time, bipedalism appeared suddenly, remained static (unchanged) for a long period of time, then underwent rapid transformation before again remaining static and undergoing another rapid change.
Australopithecines, the first bipedal primates, possessed a form of bipedalism distinct from that of the Homo primates. Australopithecines displayed facultative (optional) bipedalism whereas the Homo genus possessed and continues to possess obligatory bipedalism. Though australopithecines existed for nearly 3 million years, their bipedalism did not gradually change into the obligatory bipedalism of the Homo primates. Rather, it remained static throughout the duration of the australopithecine's existence.
With the appearance of the Homo genus, obligatory bipedalism suddenly appeared in the fossil record. From an evolutionary perspective, this quick change demanded a rapid transition process from facultative to obligatory bipedalism. Obligatory bipedalism in the Homo genus has remained static for nearly 2 million years. Interestingly, Homo erectus and Neandertals possessed an identical form of bipedalism, but a form distinct from that seen in modern humans. With the appearance of modern humans, yet another form of bipedalism suddenly appeared and has continued since its introduction.
While the pattern of stasis punctuated by sudden change seen in the fossil record runs counter to evolutionary expectations, it serves as a clear indicator of God's creative activity. If God created the australopithecines, the Homo bipedal primates, and other similar genera—a prediction can be made that the bipedalism possessed by each genus should be optimal within the context of its respective environment and lifestyle. Once created, natural selection would be expected to keep each type of bipedalism static, since any change would result in a nonoptimal form of bipedalism, compromising fitness.22 Moreover, given the differences in lifestyle and environment, it readily follows from a creation model perspective that God would create the australopithecines and Homo primates with different forms of bipedalism, as observed in the fossil record.
Recent scientific advances in the natural history of bipedalism provide a useful collection of observations that allow evaluation of both evolutionary and biblical scenarios for the origin of humanity. The sudden and early appearance of bipedalism in the fossil records allows insufficient time for bipedalism to emerge through natural process biological evolution. The fossil record also fails to reveal a pattern of gradual transformation from rudimentary bipedalism to a more sophisticated, efficient form. The absence of any significant evolutionary pressure to force these changes makes them even more remarkable.
A sudden and early appearance with two periods of stasis interspersed by rapid change defines bipedalism's natural history. These characteristics perfectly match the pattern special creation would predict.
A biblical creation model, in which God creates large bipedal primates, predicts long periods of stasis; a perfect Creator could be expected to bring about a form of bipedalism ideally suited for His creatures' environmental, predatory, and competitive challenges. The recent scientific discoveries provide explicit evidence that one of the most important defining features of humanity—bipedalism—came about through God's direct creative activity. Though not human, bipedal primates were designed for a specific purpose and function. They were the handiwork of a Creator.
With the evidence of such care toward bipedal primates, the prestige of human beings, uniquely created in the image of God, takes on tremendous significance. Being purposefully created human by a God who cares makes a person's life worth living. A society that understands such implications can extend value, meaning, and purpose to its people. And that understanding makes the discoveries related to a leap to two feet priceless.
- Genesis 1:26-27; Genesis 2:7; Genesis 2:22; Mark 10:6; Matthew 19:4; Psalm 8:4-5.
- Hugh Ross, "Can Science Test a 'God-Created-It' Model? Yes!" Facts for Faith (Q2 2000), 40-47; 55-58.
- John G. Fleagle, "Primate Locomotion and Posture," in The Cambridge Encyclopedia of Human Evolution, paperback edition, ed. Steve Jones, Robert Martin, and David Pilbeam (New York: Cambridge University Press, 1994), 75-85.
- Eric Delson et al., eds., Encyclopedia of Human Evolution and Prehistory, 2d ed. (New York: Garland Publishing, 2000), 394-95; B. Bower, "African Fossils Flesh Out Humanity's Past," Science News 155 (1999), 262; Elizabeth Culotta, "A New Human Ancestor?" Science 284 (1999), 572-73; Jean de Heinzelin et al., "Environment and Behavior of 2.5 Million-Year-Old Bouri Hominids," Science 284 (1999), 625-29; Berhane Asfaw et al., "Australopithecus garhi: A New Species of Early Hominid from Ethiopia," Science 284 (1999), 629-35.
- Roger Lewin, Principles of Human Evolution: A Core Textbook (Malden, MA: Blackwell Science, 1998), 219-22.
- Lewin, 227.
- Lewin, 224-26.
- Fleagle, 75-78.
- Lewin, 227.
- Lewin, 218; Robert Martin, "Walking on Two Legs," in The Cambridge Encyclopedia of Human Evolution, paperback edition, ed. Steve Jones, Robert Martin, and David Pilbeam (New York: Cambridge University Press, 1994), 78; Fred Spoor et al., "Implications of Early Hominid Labyrinithine Morphology for Evolution of Human Bipedal Locomotion," Nature 369 (1994), 645-49.
- Tim D. White et al., "Australopithecus ramidus, a New Species of Early Hominid from Aramis, Ethiopia," Nature 371 (1994), 306-12; Henry Gee, "New Hominid Remains Found in Ethiopia," Nature 373 (1995), 272.
- Tim D. White et al., "Corrigendum," Nature 375 (1995), 88.
- Meave G. Leakey et al., "New Four-Million-Year-Old Hominid Species from Kanapoi and Allie Bay, Kenya," Nature 376 (1995), 565-71.
- Meave G. Leakey et al., "New Specimens and Confirmation of an Early Age for Australopithecus anamensis," Nature 393 (1998), 62-66; B. Bower, "Early Hominid Rises Again," Science News 153 (1998), 315.
- Meave Leakey and Alan Walker, "Early Hominid Fossils from Africa," Scientific American (June 1997), 74-79; Clark Spencer Larsen, Robert M. Matter and Daniel L. Gebo, Human Origins: The Fossil Record, 3d ed. (Prospect Heights, IL: Waveland Press, 1998), 46.
- Lewin, 258; 266-69.
- Michel Brunet et al., "The First Australopithecine 2,500 Kilometers West of the Rift Valley (Chad)," Nature 378 (1995), 273-75.
- Meave G. Leakey et al., "New Hominid Genus from Eastern Africa Shows Diverse Middle Pliocene Lineages," Nature 410 (2001), 433-40.
- Lewin, 222.
- Mark A. Cane and Peter Molnar, "Closing of the Indonesian Seaway as a Precursor to East Africa Aridification Around 3-4 Million Years Ago," Nature 411 (2001), 157-62.
- François Marchal, "A New Morphometric Analysis of the Hominid Pelvis Bone," Journal of Human Evolution 38 (2000): 347-65.
- Niles Eldredge, Reinventing Darwin: The Great Debate at the High Table of Evolutionary Theory (New York: John Wiley, 1995), 78-81.
Sidebar: The Evolutionary Perspective of Human Origins
Fazale R. Rana
Current models for human evolution describe modern humans as gradually emerging from more primitive "hominids" (members of the primate family Hominidae) through descent with modification via natural selection and mutations. Evolutionary biologists think this process began around 5 million years ago when hominids and apes supposedly diverged from a shared ape-like ancestor.1
Australopithecines occur in the fossil record between 4.5 to 1.5 million years ago as the first bipedal primates.2 The genus Australopithecus encompasses a diverse group of hominids with ape-size brains; ape-like cranial, facial, and dental features; an ape-like torso and upper limbs; and limited bipedal capabilities distinct from modern humans.3
Until recently, paleoanthropologists viewed the australopithecines as part of the evolutionary pathway leading to modern humans. Controversy now centers around the role of australopithecines in human origins with the discovery of a new hominid genus, Kenyanthropus, dated at 3.5 million years in age.4 Some paleoanthropologists suggest that Kenyanthropus gave rise to Homo bipedal primates.5
No consensus view exists among paleoanthropologists to describe the evolutionary relationships among (extinct) australopithecines and a closely related genus, Paranthropus (originally considered "robust australopithecines").6 However, the latter's relatively large size and other unique, distinguishing features prompted paleoanthropologists to reclassify the robust australopithecines as a separate genus. Paleoanthropologists view Paranthropus as an evolutionary dead end. Given the bewildering array of species, paleoanthropologists are unclear as to which of the australopithecines could have given rise to the Homo genus of bipedal primates.
Homo bipedal primates first appear in the fossil record about 2 million years ago. Traditionally Homo habilis was regarded as the first Homo bipedal primate and the key transitional species linking the australopithecines to the Homo genus. However, newly recognized features (features more closely aligned with those of the australopithecines than with those of other Homo bipedal primates such as Homo erectus), caused H. habilis to be reclassified as an australopithecine.7 This new understanding seriously weakens the position of H. habilis as a transitional species, thus leaving a discontinuity in the hominid phylogeny.
Homo erectus and Homo neandertalensis are the two bipedal primates that have been most closely linked to modern humans. However, recent work has all but severed the link between modern humans and H. erectus, and has completely cut the connection between Neandertals and modern humans.8 Paleoanthropologists increasingly regard H. erectus as representing a side branch that resulted in an evolutionary dead end, since this bipedal primate was confined to Asia, and analysis of DNA isolated from three distinct Neandertal remains all indicate that Neandertals made no contribution to human genetic makeup.
As with the australopithecines, a menagerie of Homo bipedal primates existed for most of the last 2 million years. Paleoanthropologists, unable to reach a consensus on the evolutionary relationships among the members of the Homo genus, have been unable to identify a direct ancestor to modern humans.9 Nevertheless, many evolutionary biologists are convinced these relationships exist and the missing ancestor of modern humans will someday be discovered.
- Richard Morris, The Evolutionists: The Struggle for Darwin's Soul (New York: W. H. Freeman, 2001), 34-37.
- B. A. Wood, "Evolution of Australopithecines," in The Cambridge Encyclopedia of Human Evolution, paperback edition, ed. Steve Jones, Robert Martin and David Pilbeam (New York: Cambridge University Press, 1994), 231-240.
- Roger Lewin, Principles of Human Evolution: A Core Textbook (Malden, MA: Blackwell Science, 1998), 241-282.
- Meave G. Leakey et al., "New Hominid Genus from Eastern Africa Shows Diverse Middle Pliocene Lineages," Nature 410 (2001), 433-40; Daniel E. Lieberman, "Another Face in Our Family Tree," Nature 410 (2001), 419-20.
- B. Bower, "Fossil Skull Diversifies Family Tree," Science News 159 (2001), 180.
- Lewin, 297-307.
- Bernard Wood and Mark Collard, "The Human Genus," Science 284 (1999), 65-71; B. Bower, "Redrawing the Human Line," Science News 155 (1999), 267.
- J. M. Bermudez de Castro et al., "A Hominid from the Lower Pleistocene of Atapuereca, Spain: Possible Ancestors to Neandertals and Modern Humans," Science 276 (1997), 1392-95; Ann Gibbons, "A New Face for Human Ancestors," Science 276 (1997), 1331-33; Fuz Rana, "Up (and Away) from the Apes," Connections 1, no. 2 (2000), 3-4; Hugh Ross, "Neandertal Takes a One-Eighty," Facts & Faith 11, no. 3 (1997), 4-5; Fazale R. Rana, "DNA Study Cuts Link With The Past," Connections 2, no. 3 (2000), 3; Fazale R. Rana, "Neanderthal Genetic Diversity: From Missing Link to Special Creation," Facts for Faith (Q4 2000), 5.
- Lewin, 385-428.
Sidebar: Biblical Perspective on the Hominids
Fazale R. Rana
If humans are made in the image of God through His direct creative activity, then what is the proper biblical perspective on hominids or bipedal primates? The biblical model employed here views bipedal primates as separate species that have gone extinct since their creation. The genera Australopithecus, Kenyanthropus, and Paranthropus—all ape-like creatures—possessed limited intelligence, limited bipedal capability and, in some cases, extremely crude tools. The bipedal primates assigned to the Homo genus, such as Homo erectus and Homo neandertalensis walked upright, used crude tools, possessed intelligence and perhaps even emotional capacity, yet they were devoid of spiritual capacity and, therefore, must be regarded as distinct from modern humans.1
Bipedal primates were not created in the image of God. Paleoanthropologists have no indication from the archeological record that Neandertals, or any bipedal primates, engaged in religious activity.2 Although the Homo bipedal primates used tools, they were crude and qualitatively distinct from the sophisticated tools used by modern humans.3 Neandertals, in all likelihood did not possess language capacity.4 Genesis 1 makes no specific allusion to bipedal primates. Their creation by God on Days 5 and 6 in the group of nephesh or animals endowed with will, emotion, and intelligence can be inferred.
- Hugh Ross, The Genesis Question (Colorado Springs, CO: NavPress, 1998), 54-55; 110.
- Eric Delson et al., eds., Encyclopedia of Human Evolution and Prehistory, 2d ed. (New York: Garland Publishing, 2000), 615-17.
- Tom Clarke, "Relics: Early Modern Humans Won Hand Over Fist," Nature Science Update, (6 February 2001); Steven E. Churchill, "Hand Morphology, Manipulation, and Tool Use in Neandertals and Early Modern Humans of the Near East," Proceedings of the National Academy of Sciences, USA 98 (2001): 2953-55; Wesley A. Niewoehner, "Behavioral Inferences from the Skhul/Qafzeh Early Modern Human Hand Remains," Proceedings of the National Academy of Sciences, USA 98 (2001): 2979-84.
- Christopher Stringer and Robin McKie, African Exodus: The Origin of Modern Humanity (New York: Heary Holt and Company, 1996), 85-114.
Author's Update
By Fazale R. Rana
During the final publication stages of this article, a team of paleontologists from the University of California, Berkeley reported the discovery of hominid remains dated between 5.2 and 5.8 million years ago and described this animal's environment.1 The results of their work bolster the case for the supernatural appearance of bipedalism.2
Paleoanthropologists making this discovery assigned the fossil remains to Ardipithecus ramidus. Analysis clearly indicates that A. ramidus walked erect. This dramatic discovery not only pushes the hominid fossil record back by nearly one million years but also places the appearance of bipedalism coincidental to the first appearance of hominids. Bipedalism, indeed, appears suddenly in the fossil record.
The paleoanthropologists also determined that A. ramidus lived exclusively in a wet woodland environment. Likewise, the A. ramidus specimen dated at 4.4 million years in age lived in a wet woodland habitat.3 These discoveries fully eliminate the evolutionary driving force for bipedalism's emergence. As one researcher commented, these discoveries "challenge some long-cherished ideas about the mode and timing of hominid evolution."4
- Yohannes Haile-Selassie, "Late Miocene Hominids from the Middle Awash, Ethiopia," Nature 412 (2001), 178-81; Giday WoldeGabriel et al., "Geology and Paleontology of the Late Miocene Middle Awash Valley, Afar Rift, Ethiopia," Nature 412 (2001), 175-78.
- Henry Gee, "Return to the Planet of the Apes," Nature 412 (2001), 131-32; Michael Balter and Ann Gibbons, "Human Evolution: Another Emissary from the Dawn of Humanity," Science 293 (2001), 187-89.
- Giday WoldeGabriel et al., "Ecological and Temporal Placement of Early Pliocene Hominids at Aramis, Ethiopia," Nature 371 (1994), 330-33.
- Balter and Gibbons, 187-88.
Body and Soul Part II: Why the Soul is Immaterial
By J. P. Moreland, Ph.D.
Tom's mother lies in a hospital bed in a darkened room. Suddenly, the blips on her heart monitor become erratic. Within seconds, a flat line appears. A nurse hurries into the room and turns the monitor off. After a long illness, Tom's mom is dead. But is she?
What if Tom's mother's soul survives as a distinctly separate entity after her brain waves cease and her human body no longer lives? If such is the case, the stage is set for discussion of life beyond death, and the subject of the immaterial nature of the soul takes on deep significance. Immaterial in this context means "having no physical or material reality," not that Mom's soul is inconsequential. Precisely because such a human being matters so much, understanding the relationship between body and soul carries great importance.
Part I of this series showed how the properties that make up one's stream of consciousness are not physical, but genuinely mental. This article, Part II, argues that a human being's soul or self (e.g., a mother's soul) is immaterial (or non-material). Before considering the arguments, the reader may wish to review briefly the nature of a physical substance.
Substances are particular individual things like acorns, carbon atoms, or moms. A substance, like a particular mom, cannot be in more than one place at the same time (no matter how much she might like for her children to believe otherwise).
Substances are basic fundamental things. They are not in other things or aspects of other things. Though an adult child may be convinced at times that Mom lives inside his head, she is in fact a substance, a separate entity made up of parts, properties, and capacities (dispositions, tendencies, and potentialities). Mom has a number of parts such as eyes, mouth, a broken fingernail, and a stubbed toe. Properties include her weight and age. New properties can change, yet the substance remains the same throughout that change. For instance, Mom's hair may go from the property of gray to the property of blonde, but she'll always be Mom.
In addition, Mom has some capacities or potentialities that are not always actual. For example, she has the capacity to invoke discipline even though she may choose to wait until Dad comes home.
Substance dualists assert that as a human, Mom consists of an immaterial substantial soul with a physical body that is not identical to the soul. Because substance dualists believe that the properties of ego and consciousness are without physical material, they are also property dualists. However, an individual can be a mere property dualist without being a substance dualist by accepting the immateriality of consciousness but holding the belief that its owner is the body or, more likely, the brain. In contrast with mere property dualism, substance dualists believe that the brain is a physical thing with physical properties and the mind or soul is a mental substance that has mental properties.
When Mom is in pain, her brain has certain physical properties (e.g., electrical, chemical), and the soul or self has certain mental properties (e.g., the conscious awareness of pain). Her soul possesses its experiences. It stands behind, over, and above them and remains the same throughout her life. Mom's soul and brain can interact with each other, but they are different particulars with different properties. Since her soul is not to be identified with any part of the brain or with any particular mental experience, then it may be able to survive the destruction of the body. Substance dualists accept the existence of both mental properties and substances.
Three main forms of substance dualism are currently being debated. However, a simple argument can be made for that which all three positions hold in common; a human being's self or ego as an immaterial substance that bears consciousness.1
A Case for the Immaterial Nature of the Self
Recent literature offers at least four arguments for the disembodied identity of the soul.
1. Basic Awareness of the Self
When an individual such as a mom pays attention to her own consciousness, she becomes aware of her own self (i.e., her ego, "I," her center of consciousness) as being distinct from her body and from any particular mental experience she has. Mom simply has a basic direct awareness of the fact that she is not identical to her body or her mental events; rather, she is the self that has a body and a conscious mental life.
The following example illustrates this point. Mom's son looks at chocolate chip cookies sitting on a counter and walks toward them. In so doing, he experiences a series of what are called phenomenological objects or cookie representations. That is, several different cookie experiences replace one another in rapid succession. As he approaches the cookies, cookie sensations change. The aroma grows stronger. What originally may have appeared to be ants take shape and become recognized as chocolate chips. Further, because of the lighting in the kitchen, the cookies change color slightly, they may be a little on the dark side. The cookies don't actually change in smell, shape, or color; but the son's cookie "experiences" do.
Of course, the son is aware of all the different experiences of the cookies during the fifteen seconds it took to walk across the room. But if paying attention, the son is also aware of two more things. First, he does not simply experience a series of sense-images of a cookie. Rather, through self-awareness, the fact is also experienced that it is "I" the self who has each cookie experience. Each cookie sensation produced at each angle of perspective has a perceiver who is I. An "I" accompanies each sense experience to produce a series of awarenesses—"I am experiencing a cookie sense image now".
The son is also aware of the basic fact that the same self that currently has a fairly large cookie experience (especially as the hand comes to within reach of the cookie) is the very same self as the one who had all of the other cookie experiences preceding this current one. In other words, through self-awareness, one gains an awareness of the fact that "I" am an enduring "I" who was and is (and will be) present as the owner of all the experiences in the series.
These two facts—"I" am the owner of self-experience, and "I" am an enduring self who exists as the same possessor of all self-experience through time—show that a person is not identical to his experiences. Self (or "I) is the thing that has them. In short, "I" is a mental substance. Only a single enduring self can relate and unify experiences, a fact that property dualists and physicalists cannot adequately account for or explain away.
2. More than Third Person
A complete physicalist description of the world would be one in which everything would be exhaustively described from a third-person point of view in terms of objects, properties, processes, and their spatiotemporal locations. For example, a description of a cookie in a room would go something like this: "An object exists three feet from the south wall of the kitchen and two feet from its east wall, and that object has the properties of being light brown, circular, sweet, and so on."
The first-person point of view is the vantage point used to describe the world from one's own perspective. Expressions of a first-person point of view use what are called indexicals—words such as "I," "here," "now," "there," and "then." Here and now are where and when "I"am. There and then are where and when "I" am not. Indexicals refer to me myself. "I" is the most basic indexical and refers to a self that is known by acquaintance with one's own consciousness in acts of self-awareness. "I" am immediately aware of my own self and "I" know who "I" refers to when "I"use it; it refers to an individual as the self-conscious self-reflexive owner of his own body and mental states.
According to physicalism, no irreducible privileged first-person perspectives exist. Everything can be exhaustively described in an objective language from a third-person perspective. A physicalist description of a mom would say, "There exists a body at a certain location that is five feet tall, weighs 115 pounds," and so forth. The property dualist would add a description of the properties possessed by that body, such as the body is feeling pain, thinking about lunch, or can remember being on vacation with her children in Grandview, Missouri, in 1965.
But no amount of third-person description can capture Mom's own subjective first-person acquaintance of her own self in acts of self-awareness. In fact, for any third-person description, an open question always exists as to whether the person described in third-person terms is the same person as Mom. She knows her self not because she knows some third-person description of a set of mental and physical properties and because a certain person satisfies that description. She knows herself as an ego immediately through being acquainted with her own self. She expresses that self-awareness by using the term "I."
"I"refers to Mom's own substantial soul. It does not refer to any mental property or bundle of mental properties she is having, nor does it refer to any body described from a third-person perspective. "I"is a term that refers to something that exists, and does not refer to any object or set of properties described from a third-person point of view. Rather, "I"refers to Mom's own self with which she is directly acquainted and who, through acts of self-awareness, she knows to be the substantial possessor of her mental states and her body.
3. The Modal Argument
Thought experiments have rightly been central to debates about personal identity. For example, people are often invited to consider situations in which two persons switch bodies, brains, or personality traits or in which a person exists disembodied. In these thought experiments, someone argues in the following way: Because a certain state of affairs S (e.g., Mom's existing in a disembodied state) is conceivable, one can justifiably think that S is metaphysically possible. Now if S is possible, then certain implications follow about what is/is not essential to personal identity (e.g., Mom is not essentially a body).
People use conceiving as a test for possibility/impossibility throughout their lives. Mom knows that her son can become President (even if she thinks it is highly unlikely) because she can conceive it to be so. She knows square circles are impossible because they are inconceivable, given her knowledge of being square and being circular. To be sure, judgments that a state of affairs is possible/impossible grounded in conceivability are not infallible. They can be wrong. Still, they provide strong evidence for genuine possibility/impossibility. In light of this, this author offers the following criterion:
For any entities x and y, if grounds exist for believing one can conceive of x existing without y or vice versa, then an individual has good grounds for believing x is not essentially identical to y or vice versa.
Application of these insights about conceivability and possibility to the modal argument for substance dualism comes in many forms. One version of the argument can be stated in the following way:2
- The law of identity: If x is identical to y, then whatever is true of x is true of y and vice versa.
- Mom can conceive of herself as existing in a disembodied state.
- If she can strongly conceive of some state of affairs S that S possibly attains, then she has good grounds for believing of S that S is possible.
- Therefore, she has good grounds for believing of herself that it is possible for her to exist and be disembodied.
- If some entity x can possibly exist without y, then (i) x is not identical to y and (ii) y is not essential to x.
- Mom's body cannot possibly exist disembodied (i.e., her body is essentially a body).
- Therefore, she has good grounds for believing of herself that she is not identical to her body and that her physical body is not essential to her.
A parallel argument can be advanced in which the notions of a body and disembodiment are replaced with the notions of physical objects. So understood, the argument implies the conclusion that Mom has good grounds for thinking that she is not identical to a physical particular nor is any physical particular essential to her. A parallel argument can also be developed to show that possessing the ultimate capacities of sensation, thought, belief, desire, and volition are essential to her, that is, she is a substantial soul or mind.
A full defense of the argument cannot be undertaken here, but the second point, which states "Mom can strongly conceive of herself as existing disembodied," compels further discussion. A number of things that make a person (Mom, in this case) aware of her "self" and of her body give support to the conceivability expressed in the statement. Mom is aware that she is unextended ("fully present" at each location in her body, as Augustine claimed), that she is not a complex aggregate of separable parts, nor is she the sort of thing that can be composed of physical parts. Rather she is a basic, unity of inseparable faculties (of mind, volitions, emotion, etc.) that sustains absolute sameness through change, and that she is not capable of gradation (she cannot become two-thirds of a person, not even if her legs are amputated or she loses some of her memory at age 90).3
In some near death experiences, people report themselves to have been disembodied. They are not aware of having bodies in any sense. Rather, they are aware of themselves as unified egos that exemplify sensations, thoughts, and so forth.
Moreover, Christians who understand the biblical teaching that God is a bodiless spirit also understand by direct introspection that they are made in God's image in the sense that they are spirit but also have human bodies. New Testament implies that people will and, therefore, can exist temporarily without their bodies. In II Corinthians 12:1-4, Paul asserts that he may actually have been disembodied. Surely Paul's willingness to consider this a real possibility came at least in part from an awareness of his own nature through introspection, his recognition of his similarity to God in this respect, and his knowledge of biblical teaching.
All these factors imply that people can conceive of themselves as existing in a disembodied state. This implication provides grounds for thinking of such a case as being a real possibility (even if it is false though, of course, this author does not think it is false).
4. Free Will, Morality, and Responsibility
To say that a human is a free will being is to say that humans exercise what is called libertarian freedom: Given choices A and B, a person can literally choose either one. No circumstances exist that are sufficient to determine a choice. A person's choice is up to the individual, and if Mom does A or B, she could have done otherwise. She acts as an agent who is the first cause or ultimate originator of her own actions. Moreover, her reasons for acting do not partially or fully cause her actions, she does. Rather, her reasons are the teleological goals—the purposes or the ends—for the sake of which she acts. If Mom takes a nap because she's tired, the desire to satisfy her need for rest is the end for the sake of which she acts freely.
If physicalism is true, then human free will does not exist. Instead, determinism is true.4 If Mom is purely a physical system, nothing in her has the capacity to freely choose to do something. Material systems, at least large-scale ones, change over time in deterministic fashion according to the initial conditions of the system and the laws of chemistry and physics to which such systems are subject. A pot of water reaches a certain temperature at a given time in a way determined by the amount of water, the input of heat, and the laws of heat transfer.
Moral obligation and responsibility make little or no sense if determinism is true. Morality seems to presuppose freedom of the will. If Mom "ought" to do something, it seems necessary to suppose that she can do it, that she is in control of her actions. No one would say that she ought to jump to the top of a fifty-floor building to save a baby, or that she ought to stop the American Civil War. Clearly, she does not have the ability. If physicalism is true, Mom does not have any genuine ability to choose her actions. Further, since free acts seem to be for the sake of goals or ends, if physicalism (or mere property dualism) is true, there is no ultimate purpose and, thus, there can be no libertarian free acts.
One may safely say that physicalism requires a radical revision of common-sense notions about freedom, moral obligation, responsibility, and punishment. On the other hand, if these common-sense notions are true, physicalism is false.
The same problem besets property dualism. Property dualists handle human actions in two ways. First, some property dualists are epiphenomenalists (e-pi-fi-′na-me-nal-ists). This belief proposes that a person is a living physical body having a mind, the mind consisting, however, of nothing but a more or less continuous series of conscious or unconscious states and events . . . which are the effects, but never the causes of bodily activity. Put another way, when matter reaches a certain organizational complexity and structure, as is the case with the human brain, then matter produces mental states as a fire produces smoke. The mind is to the body as smoke is to fire. Smoke is different from fire (to keep the analogy going, the physicalist would identify the smoke with the fire or the functioning of the fire), but fire causes smoke, not vice versa. The mind is a by-product of the brain, which causes nothing; the mind merely "rides" on top of the events in the brain. Hence, epiphenomenalism rejects free will, for it denies that mental states cause anything.
A second way that property dualists handle human action is through a notion called event-event causation. To understand event-event causation, consider a baseball that breaks a window. The cause in this case is not the baseball itself (which is a substance), but an event: the baseball's being in a certain state—a state of motion. The effect is another event: the window being in a certain state—the breaking state. Thus, one state or event—the throwing of a baseball—causes another state or event to occur—the breaking of the window. Further, according to event-event causation, whenever one event causes another, some deterministic or probabilistic law of nature relates the two events. The first event combined with the law of nature is sufficient to determine or fix the chances for the occurrence of the second event.
In contrast to the property dualist employment of either epiphenomenalism or event-event causation (which deny genuine free will) stands agent causation, which is an important part of an adequate libertarian account of freedom of the will. One example of agent causation is a typical case of a human action: Mom's raising her arm and throwing the baseball. When she raises her arm, she, as a substance, simply acts by spontaneously exercising her causal powers. She raises her arm; she freely and spontaneously exercises the powers within her substantial soul and simply acts. No set of conditions exists within her that is sufficient to determine that she raises her arm. Moreover, this substantial agent is characterized by the power of active freedom, conscious awareness, the ability to think, form goals and plans, to act teleologically, and so forth. Such an agent is an immaterial substance and not a physical object. Thus, libertarian freedom is best explained by substance dualism and not by physicalism or mere property dualism.
In summary then, substance dualism offers the libertarian freedom denied by property dualism because it adopts either epiphenomenalism or event-event causation. Thus, given the truth of a libertarian account of free will, moral ability, and moral responsibility; property dualism, no less than physicalism, is false. One's commonsense notions about moral ability and responsibility are almost self-evident. People all operate toward one another on the assumption that these are true concepts (and these common-sense notions seem to assume libertarian free will). However, if physicalism or property dualism is true, people have to abandon and revise their common-sense notions of moral ability, and responsibility because free will is ruled out. One wonders if such a revision is worth the price. These common-sense notions seem more reasonable than physicalism or property dualism. If anything should be abandoned, it is the latter, not the former.
The first two articles of this series present good reasons for accepting the fact that consciousness is not physical but, rather, consists of genuinely mental properties and events. Solid grounds make a case for believing that a human being's (e.g., a mom's) ego or self is an immaterial spiritual owner of consciousness. As such, the possibility exists that though the physical body of Tom's mother may die, his mom's self may live on. But for an adequate treatment of the body and soul discussion, one needs to examine various versions of physicalism. This task remains for part III of this series.
- For a more complete treatment of the three views on substance dualism see Richard Swinburne, The Evolution of the Soul (Oxford: Clarendon, rev. ed., 1997); J.P. Moreland and Scott Rae, Body and Soul (Downers Grove, Ill.: InterVarsity, 2000); William Hasker, The Emergent Self (Ithaca, NY: Cornell University Press, 1999).
- Cf. Keith Yandell, "A Defense of Dualism," Faith and Philosophy 12 (October 1995): 548-566; Charles Taliaferro, "Animals, Brains, and Spirits," Faith and Philosophy 12 (October 1995): 567-581.
- In normal life, Mom may be focused on speaking kindly and unaware that she's scowling. In extreme cases (multiple personalities and split brains), she may be fragmented in her functioning or incapable of consciously and simultaneously attending to all of her mental states, but the various personalities and mental states are still all hers.
- For four reasons, quantum indeterminacy is irrelevant here: (1) The best interpretation of quantum indeterminacy may be epistemological (knowing) and not ontological (being). (2) Even if micro-indeterminacy is real, macro-objects such as the brain may still be deterministic in their behavior. (3) Granting micro- and macro-indeterminacy for the sake of argument, quantum indeterminacy is still irrelevant to issues about libertarian freedom for two reasons: a) The occurrence of an uncaused, indeterminate event inside of a person still does not yield a free act because the latter requires that the agent has control over the act which, arguably, would not be present if a random, uncaused event just happened to occur in the agent. b) As will be noted below, indeterministic physical causation depicts causes and effects as events that stand in the proper law of nature such that, given the cause and the (statistical) law, the chances for the effect are fixed. But in a libertarian free act, the chances of the act occurring are not fixed by any prior conditions. (4) Even if diachronic indeterminism is granted, there is still the problem of synchronic micro to macro emergent determinism of macro-objects and their behavior on their ultimate physical parts. For these reasons, this researcher will continue to talk about determinism. Those who think such talk is inappropriate given quantum indeterminacy should realize that, in light of these four points, such talk is not at all inappropriate.
A Salute to the General of Education:
Mortimer J. Adler
By Kenneth Richard Samples
The motto for the National Negro College Fund sends chills up my spine whenever I hear it: "A mind is a terrible thing to waste." For a Christian, however, the message is even more challenging. The mind of a creature made in the image and likeness of an infinite, eternal, and personal God is a fortiori—Latin for "with greater force" or "all the more"—a terrible thing to waste.1 Because the human soul survives death, cultivating the life of the mind to the glory of God takes on an eternal dimension. The scriptural imperative of Matthew 22:37 calls us to love the Lord our God with all our being. This all includes, of course, God's incredible gift of the mind.
Humanity's intellectual abilities directly result from our being the crown of God's creation. It is the Imago Dei, the image of God, that distinguishes us from the animals, and it is that same image that makes the life of the mind so important. Only human beings pursue, discover, and reflect upon such concepts as logic, science, mathematics, philosophy, morality, the arts, and God. It is left to human beings alone to be time and reality conscious, to philosophize by recollecting the past, recognizing the present, and anticipating the future.
The Bible instructs Christians to practice not only the moral virtues it delineates, but also intellectual virtues. Believers are exhorted to pursue "wisdom, knowledge, and understanding," all of which are rooted in "the fear of the Lord."2 Discernment, reflection, testing, and intellectual renewal are all biblical mandates that produce honorable character and innumerable blessings if Christians heed them.3 Of all people, the Christian who understands the implications of being made in the Imago Dei will value the "life of the mind."4 Simply stated, the Christian's endeavor to develop his/her mind represents an act of worship toward the infinite and eternal God who made sentient beings and everything else in creation.
The person who has done the most to help me value and pursue the life of the mind has just died. The distinguished philosopher and educator Mortimer J. Adler (1902-2001), to whom I owe an enormous debt of gratitude, genuinely enriched my life. His promotion of the Great Books reading program encouraged me to pursue the Western classics, including, among others, works of literature, philosophy, science, and politics. That pursuit has put me in touch with such brilliant and passionate minds as Plato, Aristotle, Augustine, Aquinas, Pascal, and others. Adler challenged me, as he challenged all, to read the original writings of these great thinkers and glean the wisdom of their books—books which have truly stood the test of time. While some Christians are hesitant to read works by non-Christian authors, such as Darwin, Marx, Nietzsche, and Freud, I have been strengthened in my modest role as an apologist by pursuing a broad liberal arts education. This education exposed me to the rich marketplace of ideas that forms the intellectual history of Western civilization.
I have also benefited from a number of Adler's own works. His books How To Read A Book (which I have assigned as a textbook in some college-level courses) and How To Speak, How To Listen have significantly enhanced my experience of reading and understanding of rhetoric. Adler taught me that even after earning a graduate degree I still had much to learn about the four types of reading: elementary, skimming, analytical, and syntopical. His books The Paideia Program, which promotes a truly classical public education, and Reforming Education have influenced the way I teach and the way I guide my children's education. Because of Adler's inspiration and example, my wife and I are all the more committed to doing all we can to help our children develop flourishing intellectual lives to the glory of God.
Adler, the longtime chairman of the board of editors for Encyclopaedia Britannica, and the author of some sixty books, has left an intellectual legacy that will influence many generations to come. Surrounded by a cultural flood of relativism, he tirelessly defended the absolutes of truth and morality. I hope you will reap benefit from his brief but provocative article on education. Those who would like to know more about Adler and his body of work may contact his Center for the Study of the Great Ideas at TheGreatIdeas.org.5 Those interested in Adler's conversion to Christianity will want to read his brief spiritual autobiography in Philosophers Who Believe.6
Regarding stewardship of the human mind, Mortimer J. Adler emphatically asserts, "It is man's glory to be the only intellectual animal on earth. That imposes upon human beings the moral obligation to lead intellectual lives."7
- Gen. 1:26-27.
- Job 28:28; 34:4; Ps. 111:10; Prov. 1:7; 9:10.
- Acts 17:11; Rom. 12:2; 1 Cor. 14:29; Col. 2:8; 1 Thes. 5:21.
- For evangelical Christians who want to seriously pursue the life of the mind, see Mark A. Noll, The Scandal of the Evangelical Mind (Grand Rapids: Eerdmans, 1994) and J. P. Moreland, Love Your God With All Your Mind (Colorado Springs, CO: NavPress, 1997).
- The Great Ideas Online (www.TheGreatIdeas.org) is published by the Center for the Study of The Great Ideas. Max Weismann, Co-Founder and Director. 845 North Michigan Avenue Suite 950W, Chicago, IL 60611. Phone: (312) 440-9200. Fax: (312) 440-0477. E-mail: firstname.lastname@example.com.
- Mortimer J. Adler, Philosophers Who Believe: The Spiritual Journeys of 11 Leading Thinkers, ed. Kelly James Clark (Downers Grove, IL: InterVarsity, 1993), 203-21.
- Mortimer J. Adler, Intellect: Mind over Matter (New York: Collier Macmillan, 1990), 185.
Reading Between the Fossil Lines
By Gleason L. Archer
One of the most frequently argued objections to the trustworthiness of Scripture is found in the apparent discrepancy between the account of creation given in Genesis 1 and the supposed evidence from the fossils and fissionable minerals in the geological strata that indicated Earth is billions of years old. Yet Genesis 1 allegedly teaches that creation took place in six twenty-four-hour days, at the end of which man was already on the earth. But this conflict between Genesis 1 and the factual data of science (in contradistinction to the theories of some scientists who draw inferences from their data that are capable of quite another interpretation by those equally proficient in geology) is only apparent, not real.
To be sure, if we were to understand Genesis 1 in a completely literal fashion—which some suppose to be the only proper principle of interpretation if the Bible is truly inerrant and completely trustworthy—then there would be no possibility of reconciliation between modern scientific theory and the Genesis account. But a true and proper belief in the inerrancy of Scripture involves neither a literal nor a figurative rule of interpretation. What it does require is a belief in whatever the biblical author (human and divine) actually meant by the words he used.
An absolute literalism would, for example, commit us to the proposition that in Matthew 19:24 (and parallel passages) Christ actually meant to teach that a camel could go through the eye of a needle. But it is abundantly clear that Christ was simply using the familiar rhetorical figure of hyperbole in order to emphasize how difficult it is spiritually for a rich man (because of his pride in his material wealth) to come to repentance and saving faith in God. To construe that passage literally would amount to blatant heresy, or at least a perversity that has nothing to do with orthodoxy. Or again, when Jesus said to the multitude that challenged Him to work some miracle, "Destroy this temple, and in three days I will raise it up" (John 2:19), they grievously erred when they interpreted His remarks literally. John 2:21 goes on to explain that Jesus did not mean this prediction literally but spiritually: "But He was speaking about the temple of His body. Therefore when He was raised from the dead, His disciples remembered that He said this, and they believed the Scripture." In this case, then, literal interpretation was dead wrong because that was not what Jesus meant by the language He used; He was actually referring to the far greater miracle of His bodily resurrection.
It thus becomes clear in this present case, as we study the text of Genesis 1, that we must not short-circuit our responsibility of careful exegesis in order to ascertain as clearly as possible what the divine author meant by the language His inspired prophet (in this case probably Moses) was guided to employ. Is the true purpose of Genesis 1 to teach that all creation began just six twenty-four-hour days before Adam was "born"? Or is this just a mistaken inference that overlooks other biblical data having a direct bearing on this passage? To answer this question we must take careful note of what is said in Genesis 1:27 concerning the creation of man as the closing act of the sixth creative day. There it is stated that on the sixth day (apparently toward the end of the day, after all the animals had been fashioned and placed on the earth—therefore not long before sundown at the end of that same day), "God created man in His own image; He created them male and female." This can only mean that Eve was created in the closing hour of Day Six, along with Adam.
As we turn to Genesis 2, however, we find that a considerable interval of time must have intervened between the creation of Adam and the creation of Eve. In 2:15 we are told that Yahweh Elohim (i.e., the Lord God) put Adam in the Garden of Eden as the ideal environment for his development, and there he was to cultivate and keep the enormous park, with all its goodly trees, abundant fruit crop, and four mighty rivers that flowed from Eden to other regions of the Near East. In 2:18 we read, "Then the Lord God said, 'It is not good for the man to be alone; I will make him a helper suitable for him.'" This statement clearly implies that Adam had been diligently occupied in his responsible task of pruning, harvesting fruit, and keeping the ground free of brush and undergrowth for a long enough period to lose his initial excitement and sense of thrill at this wonderful occupation in the beautiful paradise of Eden. He had begun to feel a certain lonesomeness and inward dissatisfaction.
In order to compensate for this lonesomeness, God then gave Adam a major assignment in natural history. He was to classify every species of animal and bird found in the preserve. With its five [sic] mighty rivers and broad expanse, the garden must have had hundreds of species of mammal, reptile, insect, and bird, to say nothing of the flying insects that also are indicated by the basic Hebrew term 'ôp ("bird") (2:19). It took the Swedish scientist Linnaeus several decades to classify all the species known to European scientists in the eighteenth century. Doubtless there were considerably more by that time than in Adam's day; and, of course, the range of fauna in Eden may have been more limited than those available to Linnaeus. But at the same time it must have taken a good deal of study for Adam to examine each specimen and decide on an appropriate name for it, especially in view of the fact that he had absolutely no human tradition behind him, so far as nomenclature was concerned. It must have required some years, or, at the very least, a considerable number of months for him to complete this comprehensive inventory of all the birds, beasts, and insects that populated the Garden of Eden.
Finally, after this assignment with all its absorbing interest had been completed, Adam felt a renewed sense of emptiness. Genesis 2:20 ends with the words "but for Adam no suitable helper was found." After this long and unsatisfying experience as a lonely bachelor, God saw that Adam was emotionally prepared for a wife—a "suitable helper." God, therefore, subjected him to a deep sleep, removed from his body the bone that was closest to his heart, and from that physical core of man fashioned the first woman. Finally God presented woman to Adam in all her fresh, unspoiled beauty, and Adam was ecstatic with joy.
As we have compared Scripture with Scripture (Gen 1:27 with 2:15-22), it has become very apparent that Genesis 1 was never intended to teach that the sixth creative day, when Adam and Eve were both created, lasted a mere twenty-four hours. In view of the long interval of time between these two, it would seem to border on sheer irrationality to insist that all of Adam's experiences in Genesis 2:15-22 could have been crowded into the last hour or two of a literal twenty-four-hour day. The only reasonable conclusion to draw is that the purpose of Genesis 1 is not to tell how fast God performed His work of creation (though, of course, some of His acts, such as the creation of light on the first day, must have been instantaneous). Rather, its true purpose was to reveal that the Lord God who had revealed Himself to the Hebrew race and entered into personal covenant relationship with them was indeed the only true God, the Creator of all things that are. This stood in direct opposition to the religious notions of the heathen around them, who assumed the emergence of a pantheon of gods in successive stages out of preexistent matter of unknown origin, actuated by forces for which there was no accounting.
Genesis 1 is a sublime manifesto, totally rejecting all the cosmogonies of the pagan cultures of the ancient world as nothing but baseless superstition. The Lord God Almighty existed before all matter, and by His own word of command He brought the entire physical universe into existence, governing all the great forces of wind, rain, sun, and sea according to His sovereign will. This stood in stark contrast to the clashing, quarreling, capricious little deities and godlets spawned by the corrupt imagination of the heathen. The message and purpose of Genesis 1 is the revelation of the one true God who created all things out of nothing and ever keeps the universe under His sovereign control.
The second major aspect of Genesis 1 is the revelation that God brought forth His creation in an orderly and systematic manner. There were six major stages in this work of formation, and these stages are represented by successive days of a week. In this connection it is important to observe that none of the six creative days bears a definite article in the Hebrew text; the translations "the first day," "the second day," etc., are in error. The Hebrew says, "And the evening took place, and the morning took place, day one" (1:5). Hebrew expresses "the first day" by hayyôm hāri'šôn, but this text says simply yôm 'ehād ("day one"). Again, in v.8 we read not hayyôm haššēnî ("the second day") but yóm šēní ("a second day"). In Hebrew prose of this genre, the definite article was generally used where the noun was intended to be definite; only in poetic style could it be omitted. The same is true with the rest of the six days; they all lack the definite article. Thus they are well adapted to a sequential pattern, rather than to strictly delimited units of time.
Genesis 1:2-5 thus sets forth the first stage of creation: the formation of light. This must have meant primarily the light of the sun and the other heavenly bodies. Sunlight is a necessary precondition to the development of plant life and animal life, generally speaking (though there are some subterranean forms of life that manage to do without it).
Genesis 1:6-8 presents the second stage: the formation of an "expanse" (rāqía') that separated between moisture in suspension in the sky and moisture condensed enough to remain on the earth's surface. The term raqía' does not mean a beaten-out metal canopy, as some writers have alleged—no ancient culture ever taught such a notion in its concept of the sky—but simply means "a stretched-out expanse." This is quite evident from Isaiah 42:5, where the cognate verb rāqa' is used: "Thus says the God Yahweh, the Creator of the heavens, and the one who stretched them out [from the verb nātāh,'to extend' curtains or tent cords], the one who extended [rōqa'] the earth and that which it produces [the noun se'e sā'ímrefers always to plants and animals]." Obviously rāqa' could not here mean "beat out," "stamp out" (though it is often used that way in connection with metal working); the parallelism with nātāh (noted above) proves that here it has the force of extend or expand. Therefore, the noun rāqîa' can mean only "expanse," without any connotation of a hard metal plate.
Genesis 1:9-13 relates the third stage in God's creative work, the receding of the waters of the oceans, seas, and lakes to a lower altitude than the masses of land that emerged above them and thus were allowed to become dry. Doubtless the gradual cooling of the planet Earth led to the condensation of water necessary to bring about this result; seismic pressures producing mountains and hills doubtless contributed further to this separation between land and sea. Once this dry land (hayyabbāšāh) appeared, it became possible for plant life and trees to spring up on the earth's surface, aided by photosynthesis from the still beclouded sky.
Genesis 1:14-19 reveals that in the fourth creative stage God parted the cloud cover enough for direct sunlight to fall on the earth and for accurate observation of the movements of the sun, moon, and stars to take place. Verse 16 should not be understood as indicating the creation of the heavenly bodies for the first time on the fourth creative day; rather it informs us that the sun, moon, and stars created on Day One as the source of light had been placed in their appointed places by God with a view to their eventually functioning as indicators of time ("signs, seasons, days, years") to terrestrial observers. The Hebrew verb wayya'aś in v.16 should better be rendered "Now [God] had made the two great luminaries, etc.," rather than as simple past tense, "[God] made." (Hebrew has no special form for the pluperfect tense but uses the perfect tense, or the conversive imperfect as here, to express either the English past or the English pluperfect, depending on the context.)
Genesis 1:20-23 relates that on the fifth creative day God fully developed marine life, freshwater life, and introduced flying creatures (whether insects, lizards, or winged birds). It is interesting to observe that the fossil bearing strata of the Paleozoic era contain the first evidence of invertebrate animal life with startling suddenness in the Cambrian period. There is no indication in the pre-Cambrian strata of how the five thousand species of marine and terrestrial animal life of the Paleozoic era may have developed, for there is no record of them whatever prior to the Cambrian levels (cf. D. Dewar, "The Earliest Known Animals," Journal of the Transactions of the Victoria Institute 80 [1948]: 22-29).
Genesis 1:24-26 records that in the sixth and final stage of the creative process, God brought forth all the land animals after their various species (lemînāh in v.24 and lemînēhû in v.25 mean "according to its kind," whether the antecedent was male or female in grammatical gender), culminating finally in the creation of man, as discussed more extensively above.
In this connection, a comment is in order concerning the recurring formula at the end of each creative day: "And it was/became evening, and it became/was morning, a second day" or whatever ordinal it might be). The reason for this closing statement seems to have been twofold. First, it was necessary to make clear whether the symbolic unit involved was a mere sunrise-to-sundown day, or whether it was a twenty-four-hour day. The term yôm ("day") could mean either. in fact, the first time yôm occurs is in v.5: "And He called the light day, and the darkness He called night." Therefore, it was necessary to show that each of the creative days was symbolized by a complete twenty-four-hour cycle, beginning at sunset of the previous day (according to our reckoning) and ending with the daylight portion, down to the setting of the sun, on the following day (as we would reckon it).
Second, the twenty-four-hour day serves as a better symbol than a mere daylight day in regard to the commencement and completion of one stage of creation before the next stage began. There were definite and distinct stages in God's creational procedure. If this be the true intention of the formula, then it serves as no real evidence for a literal twenty-four-hour-day concept on the part of the biblical author.
Some have argued that the reference in the Decalogue (commandment four) to God's resting on the seventh day as a basis for honoring the seventh day of each week strongly suggests the literal nature of "day" in Genesis 1. This is not at all compelling, however, in view of the fact that there was to be any day of the week especially set aside from labor to center on the worship and service of the Lord, then it would have to be a twenty-four-hour day (Saturday) in any event. As a matter of fact, Scripture does not at all teach that Yahweh rested only one twenty-four-hour day at the conclusion of His creative work. No closing formula occurs at the close of the seventh day, referred to in Genesis 2:2-3. And, in fact, the New Testament teaches (in Heb. 4:1-11) that the seventh day, that "Sabbath rest," in a very definite sense has continued on right into the church age. If so, it would be quite impossible to line up the seventh-day Sabbath with the Seventh Day that concluded God's original work of creation!
One last observation concerning the word yôm as used in Genesis 2:4. Unlike some of the modern versions, KJV correctly renders this verse "These are the generations of the heavens of the earth when they were created, in the day that the Lord God made the earth and the heavens." Since the previous chapter has indicated that there were at least six days involved in creating the heavens and the earth, it is abundantly evident that yóm [sic] in Genesis 2:4 cannot possibly be meant as a twenty-four-hour day—unless perchance the Scripture contradicts itself!
Taken from Encyclopedia of Bible Difficulties by Gleason Leonard Archer, Jr. Copyright 1982 by Zondervan Corporation. Used by permission of Zondervan Publishing House.
Take a Tip from Columbo
By Gregory Koukl
Have you ever taken a verbal beating when trying to talk about Jesus? If so, try this simple approach to stop challengers mid-punch and make them take a close look at their gloves. It's called the Columbo tactic.
Lieutenant Columbo was the 1970s bumbling TV detective whose remarkable crime-solving success was based on a simple inquiry: "Do you mind if I ask you a question?"
The key to this strategy is to shift the burden of proof to the other person by asking carefully selected questions. It can even be played out Columbo style—halting, head-scratching, and apparently harmless.
The Columbo tactic is most powerful when you have a goal in mind. If you see some weakness in another's view, instead of plainly pointing out the error, expose it by asking a question in a disarming way.
Though there are literally hundreds of ways to do this, the Columbo tactic offers tremendous advantages. For one, it's interactive, inviting the other person to participate in dialogue. It's good to use on the job, too, because no preaching is involved. This approach allows you to make good headway in presenting and defending your view without actually stating your whole case. More importantly, a carefully placed question shifts the burden of proof to the other person where it may belong.
Burden of Proof
Christians tend to listen politely or take the burden on themselves to refute every fantasy a skeptic can spin out of thin air. Why let challengers off so easily, though, when they're the ones making the claim?
On a popular secular radio program in Los Angeles I stated the case against evolution. When a caller tried to use the big bang theory to argue against a Creator, I pointed out the big bang worked in my favor because any big bang needs a big "bang maker."
The caller disagreed. The big bang doesn't need God, he claimed. Then leading off with the phrase "One could say . . .," he spun a lengthy science fiction tale for the audience on how everything could come from nothing.
"You're right," I responded. "'One could say' anything he wants. But giving good reasons why we should believe the story you just told is another thing altogether." It wasn't my job to disprove his fairy tale. It was his job to demonstrate why anyone should take his musings seriously.
Remember, the one making the claim shoulders the burden of proof. For far too long skeptics have contrived fanciful challenges, then sat back and watched Christians squirm. If someone tells the story, it's his job to defend it, not my job to refute it.
Three Key Questions
Sometimes when I'm not sure how to proceed, I ask open-ended questions. The most effective open-ended question I've found is some variation of "How do you know?" Kevin Bywater of Summit Ministries has developed a three-step formula that can keep the dialogue going with even the most belligerent antagonists.
The first step is asking a clarification question: "What do you mean by that?" This question accomplishes several things. First, it immediately engages the challenger in an interactive way. Second, it's friendly because you've expressed a real interest in knowing more about the other's view. Third, it forces him to think carefully—maybe for the first time—about exactly what he believes. Fourth, it gives you valuable information about the roots of the person's thinking. So pay careful attention to the response.
Here's the second question: "How did you come to that conclusion?" This is a gentler variation of "Where did you get your facts?" Though it's similar in content, it has a kinder tone, assuming the critic has not just made an unsubstantiated claim, but has actually done some thinking.
The additional data puts you in a better position to assess and respond to the person's view. You now know what he thinks, and you also know how he thinks. He's also tipped you off about the way he reasons, giving you valuable information on how to proceed if you choose to.
I say, "If you choose to" because you may detect that it's not the time to move forward, nor are you automatically obliged to. Depending on your personality you'll face the temptation to be over-eager or under-eager. Remember, you don't always have to hit a home run. Sometimes just getting on base will do, and the first two questions accomplish that.
If you do proceed, your third question suggests an alternative. Ask, "Have you ever considered . . .," and then finish the sentence in a way appropriate to the issue. Offer an option that gently challenges the person's beliefs, possibly exploiting a weakness you uncovered in the answers to your first two queries.
The tone of these three questions is probing, but still amicable. They also employ the Golden Rule: "Do unto others as you would have them do unto you." Keep in mind that if you ask these questions you must be willing to have that person ask the same questions of you.
Christians don't have to be experts in everything. In fact, God can use believers effectively despite a lack of knowledge if we learn to ask good questions.
When someone says to you, "The Bible's been changed so many times," or "No one can know the truth about religion," or "All religions are basically the same," you don't have to retreat in silence. Instead, simply raise your eyebrows and say, "Oh? What do you mean by that?" and then, "How did you come to that conclusion?"
You might be surprised to find that many critics aren't prepared to defend their "faith," or lack of it, when asked some basic questions. As Lt. Columbo demonstrated so well—asking the right question frequently settles the case.
Greg Koukl is the founder and president of Stand to Reason and hosts his own radio talk show advocating clear-thinking Christianity and defending the Christian worldview. He is the author of Relativism—Feet Firmly Planted in Mid-Air (Baker) and over 100 articles, many of which can be found at www.str.org.
Book Reviews: Speculations on Origins
By Stuart A. Kauffman. New York: Oxford University Press, 2000. 336 pages, indexes. Hardcover; $30.00.
Reviewed by Tony N. Rogers
Why, in spite of entropy, nature's imperative to overall disorder, does life on Earth become so much more complex and biochemically diverse as time passes? Investigations asks this question while attempting to bring Stuart Kauffman's concepts of self-organization into mainstream science. A recipient of the Mac Arthur Fellowship, Kauffman has one of the keenest minds in the naturalist camp. He is a founding member of the Santa Fe Institute, where he conducts research into the emerging science of complexity. His more well known books include The Origins of Order and At Home in the Universe.
Though it addresses the question of increasing complexity, Investigations contains views that are speculative and often incomplete. Kauffman himself terms the book's subject matter "proto-science." In this context, Kauffman proposes a new "fourth law of thermodynamics" that governs the actions of autonomous agents. Within this framework, he explores the origin of life from complex reaction networks, the coevolution of autonomous agents in biospheres, the operation of complex economies, and even the development of the cosmos. The overarching principle governing these seemingly disparate processes is termed the "adjacent possible," which Kauffman describes as those things one step away from what currently exists. The book offers an example of a mixture of precursor molecules one reaction step away from forming a set of more complex organic molecules.
The origin-of-life question has clearly driven Kauffman's scientific inquiries, particularly in view of the scant progress made by evolution's advocates. Kauffman notes that Watson-Crick base-pairing in polynucleotides (such as the "RNA world" model) is the prevailing view of how self-replication began in the molecular world. However, subsequent efforts to synthesize such a system capable of self-replication have failed. Not deterred, Kauffman brings the concepts of autocatalysis, self-organization, and the "adjacent possible" to bear on the origin-of-life problem. He considers it likely, if not obvious, that self-reproducing molecular systems will spontaneously form in any large and sufficiently complex chemical reaction mixture.
Kauffman proposes an alternative model for the origin of life: a self-reproducing peptide system. In this model, no molecule would catalyze its own formation, but the system would collectively catalyze its own formation from smaller peptides. Investigations takes the potential for collective autocatalysis in complex peptide systems to be all but inevitable. However, the book never suggests how such a reaction system would spawn a genetic code or isolate itself within a membrane to sustain displacement from equilibrium. Kauffman has no ready answers to these questions at this stage of his research.
Given his assertion that life has "bootstrapped" its way into existence, Kauffman follows through with some novel ideas about the development of a biosphere. He views the proliferation of life forms in Earth's biosphere as the natural tendency of existing entities to self-organize and coevolve into structures of increasing complexity, each agent altering the fitness landscape of the rest. But why should Earth's biosphere become more diverse chemically as time passes? According to Kauffman, self-constructing agents attempt to expand, as rapidly as is sustainable, into the "adjacent possible" by acting on their surroundings to maximize the number of types of events that can happen next. Kauffman thinks an evolutionary strategy is robust if it contains alternative ways to do things in case the primary way is a dead end.
Investigations strikingly reveals how little progress naturalists seem to have made in bridging the gap between molecular systems and information-laden living organisms. In all observed naturally-occurring instances of increasing biochemical complexity, a mechanism with an overall entropy increase is the foundation. However, Kauffman's proposals don't yet offer a mechanism to explain how life's complexity, as measured by its vast information content, came to be.
In the end, it seems that the alleged "new fourth law" is a glitzy repackaging of the old familiar laws of thermodynamics. Perhaps a more fitting term for Kauffman's key concept might be the "adjacent improbable," as applied to the origin-of-life question. Only those structures and events that are permitted by the laws of chemistry and physics will be viable, and some will be far more likely than others. Kauffman fails to show how to overcome daunting statistical improbabilities in naturalistic origin-of-life scenarios. He hints at a general biochemistry (or "astrobiology") in which a generic catalytic toolkit exists, with each function performed by many possible chemical agents. However, the opposite is being observed in terrestrial biological systems: precise protein folding to achieve 3-D "lock-and-key" structures, a genetic code optimized for error recovery, and true molecular machinery.
As he develops his ideas of self-organization, Dr. Kauffman takes the reader on a grand tour of the cutting edge of modern science, often pursuing tangential details with little or no prologue. Even those with a good science background will find this book challenging in concept and delivery. A working knowledge of cell chemistry, mathematics, thermodynamics, and evolutionary theory is necessary to appreciate Investigations. Casual use of technical jargon such as "hyper-dimensional fitness landscapes," "dimensional compactification," and "Calabi-Yau space" may cause the reader's eyes to glaze over. Fortunately, Kauffman incorporates an engaging style that brings the reader back for more.
Kauffman's careful treatment of his scientific proposals, and his lucid presentation of admittedly difficult subject matter are thought provoking and educational. The scientifically literate FACTS for FAITH reader who is interested in the current research status of the naturalist paradigm will enjoy Investigations.
Dr. Tony N. Rogers is an associate professor of chemical engineering at Michigan Technological University (MTU). Prior to working at MTU, Dr. Rogers was a senior research engineer in the Center for Process Research at Research Triangle Institute. He specializes in the areas of thermophysical properties, chemical process design and simulation, and multi-criteria process optimization.
Nature, Design, and Science: The Status of Design in Natural Science
By Del Ratzsch. Albany, New York: State University, 2001. 220 pages, indexes. Softcover; $18.95.
Reviewed by Michael J. Behe.
Were the universe and life purposely designed by an intelligent agent? Many say yes and are content to take the conclusion as reliable and build on it. But the sometimes dangerous, sometimes dreary, job of academics is to probe seemingly reliable truths, no matter how obvious, to see if they are solid or not. Dangerous, because one might consciously or unconsciously set out to show that an obvious truth is false. Dreary, because one can devote the better part of life to showing that, to nobody's surprise, an obvious truth is true.
In Nature, Design, and Science, Del Ratzsch, professor of the philosophy of science at Calvin College, has addressed in an even-handed, thorough, scholarly manner the question of whether science can properly study the prospect of the intelligent design of nature. Since science depends on the laws and regularities of nature, would embracing a theory of design be a poison pill for science, undercutting those regularities and allowing ad hoc design explanations? If so, then design must be ruled out from the beginning, even before the evidence is considered. Ratzsch's ultimate answer is that design need not be detrimental to science and indeed may be beneficial. Like a fine philosopher, he covers the many distinctions necessary to reach a precise and reasonable conclusion.
The next question Ratzsch addresses is how to recognize design. His answer is to look for something he calls "counterflow;" that is, where things are arranged in a manner they wouldn't be if nature had been allowed its normal course. Counterflow by itself, though, doesn't reliably indicate intentional design—a person absentmindedly whittling a stick leaves counterflow marks, but no intended design. So in addition to counterflow, the result must match some understood pattern. If the whittling produced a replica of the U.S.S. Constellation, one could reasonably conclude it was intentionally designed. Although the idea of counterflow sounds straightforward, Ratzsch addresses many objections and what-ifs along the way.
Human intervention or design in nature produces counterflow, like a whittled stick or a bulldozed landscape. But things get trickier when one considers supernatural design. What if nature itself were designed? If counterflow is defined as what nature wouldn't naturally do, then it seems nature itself can't supply us with any instance of counterflow. Nonetheless, Ratzsch argues, people can still apprehend design in nature by secondary marks.
He further considers the main question of his book: can science legitimately test a theory that life and the universe were intentionally designed? He brushes away attempts to exclude supernatural design from science by definition. After examining various definitions of science, he concludes that design can be a legitimate theory in science and can even pose questions that would not arise with other theories. But like other scientific theories, design must stand or fall on the evidence and its ability to make sense of nature.
In a lengthy appendix Del Ratzsch goes over some technical differences he has with William Dembski, author of The Design Inference, on what goes into a conclusion of design. To a nonphilosopher the differences seem minor. Both Ratzsch and Dembski agree that people suspect design when they see something complicated ("complex" in Ratzsch's lingo; "small probability" in Dembski's) that can be recognized as fitting some special pattern ("mind correlative" to Ratzsch; "specified" to Dembski). Both also agree design is a rational conclusion that can be addressed by science. Those areas of agreement are almost the whole foundation of intelligent design. It's probably good, however, that the two disagree to some extent, since disagreement often sparks more intellectual progress than agreement.
Nature, Design, and Science is a technical monograph (it's published as part of the SUNY Series in Philosophy and Biology) that will be appreciated by philosophers, theologians, and pastors interested in the nitty-gritty of arguments over design in nature. The larger public, who have limited patience for books with subheadings such as "Supernatural Nomic Agency, Evident Counterflow, and Artifact Recognition," will nonetheless appreciate that Ratzsch is using his formidable intellect to defend an obvious truth on academic turf.
Michael J. Behe is professor of biological sciences at Lehigh University in Bethlehem, PA, and the author of Darwin's Black Box: The Biochemical Challenge to Evolution.
A Stellar Array: An Interview with Dr. David Rogstad
By Amy C. Jung
Dr. David (Dave) H. Rogstad serves as executive vice president of Reasons To Believe with the goal of developing effective teamwork. An accomplished scientist, Dave earned his Ph.D. in physics from the California Institute of Technology (Caltech). He conducted research there on galaxies for over ten years, interrupted by a two-year stint in Holland doing related research in radio astronomy. From Caltech, Dave went to the Jet Propulsion Laboratory (JPL) to supervise teams working on such projects as the Galileo mission and on Hypercube concurrent computation. Before retiring from JPL, he published over twenty scientific papers on various aspects of aperture synthesis and interferometric techniques, as well as reports on experiments in radio astronomy and related fields. Currently a consultant for JPL, Dave is cowriting a book on an antenna array technique developed by his team for the Galileo program. In this FACTS for FAITH interview, Dave speaks of his background, his involvement with Hugh Ross, and his zeal for living a successful Christian life.
FfF: How did you become interested in science, Dave?
Dave: My dad wasn't an educated man. He was a cabinetmaker—a woodworker. But, his interest in science and reading, and his example of being self-educated influenced me.
I understand you attended Caltech for graduate studies. After graduate school, what was your next professional step?
Although I was a graduate student in physics, when it came to actually doing research, I went into radio astronomy (astronomy that researches radio waves received from outside of Earth's atmosphere). At that time, astronomers didn't do radio astronomy—the physicists and engineers did. I'd been interested in astronomy as a kid, so this fit. I earned my Ph.D. doing research on neutral hydrogen gas in external galaxies. This gas is found throughout the universe, especially within galaxies. It radiates at a unique frequency called the 21 centimeter hydrogen line and can be used as a probe to discover how things move within a galaxy. Using this hydrogen line, I was able to determine how galaxies rotate and what their masses were.
How long did you work with the hydrogen line observations in galaxies?
I spent five years as a graduate student and then stayed on at Caltech doing further research in this field. When an opportunity turned up for me to work in Holland continuing this research in radio astronomy, my family moved there. For two years, we lived near the Westerbork radio observatory where I helped set up a new instrument.
Is that the reason you went . . . to help set up this instrument?
Yes. I was asked to help build an array of telescopes to do interferometry-type measurements, because of my experience with interferometry at Caltech.
That's a special radio astronomy technique. An interferometry technique is where two or more antennas work together to give information that you wouldn't get if you only used one.
You mentioned living in Holland for two years. What brought you back?
Being in Holland was fun and educational, but we returned to the United States partly because it was important to me to be able to share my faith and participate in Christian ministry. In a foreign country, this can be difficult unless you're there as a missionary. That, plus the value we placed on the influence of our extended family in the lives of our children helped make our decision. Also, I was given the opportunity to further my work at Caltech as a senior research fellow.
What was that opportunity?
I made observations of external galaxies using the hydrogen line as a probe—as a means to measure different characteristics of the galaxies. We had improved observing techniques so we could actually make maps in this hydrogen line and compare them with what can be seen through optical telescopes. These enabled me to make different discoveries and write papers on the subject.
What prompted your move from the Caltech campus to the Jet Propulsion Laboratory (JPL)?
In 1974, JPL organized a project using a radio astronomy technique to do spacecraft navigation. The technique is called VLBI, which stands for Very Long Baseline Interferometry. Radio astronomers use this technique to measure the position of radio quasars and to get details about these very distant radio objects that radiate in the radio region. Then these quasars are used as a framework for measuring the position of spacecraft. Because of my background in radio astronomy, I was considered an expert in that field. So when I decided to leave Caltech and look for other jobs, a friend of mine encouraged me to put in an application at JPL.
How did your personal relationships help determine the direction you chose?
I began thinking about how to evaluate different opportunities from a Christian perspective. What were the most important things in my life? Having a nice job was, of course, important, but further up the scale in terms of priority was my relationship with God. I asked myself, "Is where I'm going or what I'm going to do giving me a greater opportunity to grow in my relationship with God and to serve Him?"
Next was my wife, Diane. "Will where I'm going and what I'm doing enhance my relationship with her and help me fulfill my responsibilities in our relationship?" The third priority was my four children. "Will this improve my opportunity as a father to influence their lives and help them grow into responsible young men and women?" The next priority was ministry opportunities.
JPL was the best choice in terms of those priorities. I didn't want to come to the end of my life and say, "I've written numerous papers and been to countless conferences, but my kids are out on the streets taking drugs—or rejecting faith in Christ." Realizing that a poor choice could produce that kind of result, I pursued the job with JPL and have had no regrets whatsoever. I started there in 1974 and stayed until retiring last year to come to work at RTB. Diane and I have been married for about thirty-six years. The oldest three of our children are married and, to my joy, all four of them actively express their faith in Jesus Christ.
How would you describe your experience at JPL?
It was great. I enjoyed the projects I worked on and the people I worked with. The thing I liked most was that I could do what I liked to do as a scientist and as an engineer.
In about 1980, I became supervisor of a group at JPL and had many opportunities to share my faith. One of the key things I learned was that there's more fulfillment, more joy, in making someone else successful than in making myself successful. How could I make these people that I'm responsible to lead successful in what they do?
Another principle I learned is from the Old Testament. Abraham lived in the land of Canaan as a stranger, but God blessed him. His neighbors didn't want him to move away because they saw that God was with him and they reaped the benefits. That whole idea intrigued me. I prayed this would be true of me —that even though the people in my group at JPL might not be Christians or take an interest in anything I shared, that they would know they were being blessed because of God's presence in my life. And I saw God answer that prayer over the years.
Can you cite a specific incident at JPL in which you saw God work?
One particular project entailed my team helping to "save the Galileo mission." Galileo was the spacecraft that went to Jupiter. The antenna was shaped like an umbrella, but it wouldn't open up and thus couldn't be used. NASA could hardly talk to the spacecraft. The communication rate was only about 10 bits per second as opposed to the 137,000 bits per second they could receive with the big antenna. So my team tried to help solve that problem.
I told the team that I was praying God would make them creative and able to work efficiently because we were on a very tight schedule. The spacecraft was going to arrive at Jupiter in two years and we had a lot of work to do. A spacecraft doesn't wait for you. When it's there, it's there—and if you're not ready, well, too bad. The project was really very challenging.
Did your team complete the task in time?
Yes. The spacecraft arrived at Jupiter in 1995. The mission has been successful since then, in part due to my team's contribution. I continue to go back to JPL once a week as a consultant and am coauthoring a book on the antenna-arraying technique that we developed.
What brought you to Reasons To Believe?
I'd served on the board since the ministry's beginning in 1986. Hugh had asked me at various times whether I'd be willing to leave JPL and work for Reasons To Believe. He wanted me to do the same kind of apologetics work he does. I did a little, but didn't feel that was my strength. Yet, as I observed the organization, I saw the need for someone who could be a scientist as well as a team leader. I never thought of myself as an administrator, but always had this idea that maybe sometime I'd leave science and get involved in ministry.
The group at JPL would have liked me to stay there. We typically ate lunch together. One day I wasn't there and heard afterward that one team member said, "The real reason that Dave's leaving here is not that he doesn't like the job, or that he's taking a better job and going to get paid more." She went on, "This is a faith thing. It's the fulfillment of a faith-type goal. So, this is what we need to do. We need to go and say, 'Dave, I've been thinking about some of these things you've been sharing about your Christian faith over these years. And I really feel that you need to stay here longer in order to answer some of our questions.'" I went to her afterwards and said, "Nice try!" But, I was glad that their understanding of what I was doing was correct.
How did your Christian faith become so strong?
I grew up in a Christian home—a very serious Christian home. My dad was strong in his convictions and study of the Word. So was my mom. I grew up observing my sibling's reactions to our parents and their emphasis on Christian ideas and the study of God's Word.
I was a "good boy," in the sense that I didn't rebel against any of my family's values. But on the other hand, I didn't have a personal faith. I attended the Church of the Open Door in Los Angeles with my parents. The pastor was J. Vernon McGee, a tremendous Bible teacher. But as I reflect back, while there was a lot of teaching of God's Word, it didn't get my attention much. I attended Sunday school and even won a trip to junior high school camp by memorizing Scripture, but the experience didn't have a deep impact on me.
As an undergraduate student at Caltech, I remember sitting in Sunday school class and noticing that many of the students I'd grown up with were interested in studying God's Word. They had a knowledge that I didn't have. I was jealous. I kind of figured I was smarter than they were, and yet I didn't know as much about the Word. They marked in their Bibles and interacted with the teacher. So for graduation I asked my parents for a study Bible, thinking maybe I would do a little study and get smarter.
Did your parents give you the Bible?
I got the Bible and didn't read it. I just kind of set it aside. But the following year, as I started graduate studies, my motivation changed. I was curious and figured I should find out what it meant to be a Christian. I started with the more readable parts in the New Testament—the Gospel of John—and it began to get my attention. Living at Caltech at the time, I went home on weekends and asked my dad questions. And my dad, who normally had a lot to say . . . didn't. He just answered my questions. If he had said more, I might not have continued in the same way.
My dad gave me a booklet to read called the Judgment Seat of Christ. It was a little study on the passage in 1 Corinthians 3:10-15, which talks about people standing before the Lord and giving account for their lives. The Lord used it to bring awareness of past failures in my life. I came face-to-face with my need for a Savior and the need to give my life to Jesus Christ as my Lord. I spent a lot of time reading every night, and began attending a church closer to Caltech. I also joined the college group there.
One of the most important things I needed to do was clear my conscience from the failure of having cheated while a student at Caltech. I had violated the honor system in the class of an English professor who was a pretty strong atheist. This professor would read things that questioned faith and he told about his aunt who on her deathbed didn't sit around reading the Bible. Instead she read Shakespeare and other great works of literature in her last days on Earth. So after much struggle, I decided that if I wanted God's blessing in my life, I had to be willing to humble myself and go talk to him.
Early one morning I knocked on the professor's door and told him how I'd violated the honor system in his class, but since becoming a Christian, this thing bothered me and I was coming back to confess. Well, he was very gracious, commended my willingness to take the steps that I did, and said, "There's nothing we can do about it now." I must admit I was very grateful.
During that next several years, I grew as a scientist and Christian. Then, an interesting fellow showed up on the scene. Hugh Ross had completed his degree at the University of Toronto in Canada and had gotten a post doc research position at Caltech in radio astronomy.
What do you remember about meeting Hugh Ross?
I remember thinking he was kind of odd, but then of course as a scientist I was used to people being sort of odd. Hugh was very intense and highly focused on certain kinds of research. He came into my office one day because he needed information about the instrument we used, and I remember thinking as he left the office, "Well, it takes all kinds to make a world!"
Maybe a month later, I happened to go into his office and noticed on his desk a copy of a popular Christian book. I had no idea that he had any interest in Christianity so I asked him if he had read the book. He said, yeah he'd read it and thought it pretty accurate. I was kind of amazed that not only did he have an interest in Christian things, but he read books and was knowledgeable enough to check their accuracy. And I thought, "Wow, that's impressive." Even after being a Christian for a number of years, I didn't feel prepared to make that kind of statement. So I asked Hugh if he was a Christian. He said "yes," and I was delighted.
Why motivated you to change careers and come to RTB?
What excited me about the Christian life was not so much the apologetics as what it means to live as a Christian. I was tremendously challenged to understand the application of the Gospel. How do I have the presence of God in my life day-by-day so that I can live a successful life? How do I walk in the joy and victory it promises? I wanted to overcome the problems we all have with anger, bitterness, and forgiveness. I wanted clear purpose. I love being motivated to study the Word and apply it to life circumstances and relationships.
Of course, the scientific evidences and proofs that we have for our faith intrigue me. But I think the real challenge that I personally feel in sharing that scientific material is how to communicate it in a way that is understood by the interested noneducated person. Some of these people may have been too poor to afford college. Some may have gone to jail or escaped from drugs—so they don't have an education. Many of them are very bright and if they'd had the opportunity could have been highly educated professional people. They're interested in things related to science, but I need to be able to communicate in a way that's understandable.
In a way, it's similar to what motivates me to take the things that are in God's Word and make them very practical and understandable by everyone, not just intellectuals. The same challenge is to take science and my understanding of scientific issues in the Bible and make them practical and understandable.
What does the future hold?
Well, I'm excited about the opportunity at Reasons To Believe to help build a team. The main thing I want to do is help Hugh so that he doesn't have to worry about the details of running an organization. That's not his strength. I hope he feels he has someone trustworthy who doesn't have an agenda to develop his own career. I'm here to serve. Helping Hugh Ross and Reasons To Believe be successful in their mission is what I'm excited about and what I view myself doing until I can't do it anymore.
A New Direction for Stem Cell Research
By Fazale R. Rana
Linda's daughter has heart disease, Sylvia's husband Alzheimer's. Joe's neighbor has Parkinson's, Jesse's nephew is paralyzed. All of these people long for medical research to develop cures for debilitating disease and injuries.
In light of this longing, people want to know, Should stem cell research be allowed or shouldn't it? Did President George W. Bush make the right decision in allowing federal funds to go toward research on already existing embryonic stem cells? And, what other types of stem cell research can be done? Conflict and perplexity characterize discussions of this ethical quagmire.
The news media typically portray those who value human life as human life from the moment of conception as radicals opposed to scientific advances and indifferent to human suffering. What kind of response can bridge the gap between those in favor of virtually any form of biomedical advance with the potential to alleviate suffering and those who recognize that biotechnology has the potential to devalue and abuse human life? Can Christians participate in the stem cell debate in a way that expresses care and compassion—a way that might appeal to skeptics and seekers?
No thoughtful response is possible without an understanding of the basic science behind stem cell research. The following paragraphs offer a brief overview, and a ray of hope.
More than two hundred different types of cells make up the human body. These different cell types interact to form the wide range of tissues found in the human body. Specialized tissue cells develop from more generalized cells through the process of cell differentiation. Generalized cells that give rise to differentiated cells are called stem cells.[1] When a stem cell divides it produces two daughter cells: one a stem cell and the other a cell that develops into a specialized cell. This characteristic of stem cell division makes stem cells "self-renewing."
Scientists know of three types of stem cells: unipotent stem cells capable of developing into a single specialized cell type; pluripotent stem cells capable of developing into a few closely related cell types and totipotent stem cells capable of developing into any cell type found in the adult organism. The presence of stem cells in an adult allows some tissues to regenerate throughout a human's lifetime. Unfortunately, some adult tissues lack stem cells, and, therefore, cannot regenerate when impaired or in response to aging. After a heart attack, the damaged cardiac muscle cannot be replaced since adult heart tissue lacks stem cells.
Scientists have long regarded unipotent and pluripotent stem cells as the only stem cell types in adults. Totipotent cells are found exclusively in the early stages of embryonic development immediately after fertilization occurs. After fertilization, the zygote (the fertilized egg), rapidly divides several times. The resulting cells, called blastomeres, all have the potential to develop into the various tissues comprising the human body.[2] They are totipotent. Shortly after this embryonic stage, the cells begin to differentiate, sealing their developmental fate to a specific cell type. The only cells capable of developing into all tissue types are blastomeres.
Biochemical researchers looking for treatments for devastating conditions such as heart disease or spinal cord injuries are pursuing cell replacement therapies—the implanting of healthy tissue in place of damaged tissue. Few sources for replacement tissue currently exist. Researchers hope that totipotent blastomeres can be cultured in the lab and coaxed to develop into the different tissue types needed for tissue replacement. However, state-of-the-art techniques result in destruction of the embryos supplying these blastomeres.[3]
Herein lies the source of controversy in the stem cell debate. Many people view the destruction of the viable embryos from which totipotent blastomeres are harvested as nothing less than the taking of human life. They question whether this end truly justifies the means. Biomedical researchers, on the other hand, see no other source of totipotent stem cells. These scientists, especially those who do not necessarily share the perspective that man is made in God's image, become frustrated by ethical objections that delay important experiments necessary to develop technology capable of alleviating human suffering. Even more perplexing to them are objections to the use of "leftover" human embryos produced by in vitro fertilization. After all, embryos no longer needed for the procedure are slated for destruction. Many Christians do not see this use as an acceptable compromise. They see it, instead, as utter disregard for "unwanted" but immeasurably valuable human life.
Some very recent scientific advances have the potential to virtually dissolve this ethical quagmire. Until now, developmental biology has regarded adult stem cells as having only restricted capability to develop into specific tissue types. Scientists have viewed cell differentiation as mostly irreversible. However, current work suggests that this paradigm will soon be overthrown.
A team of scientists from Canada's McGill University recently isolated a unique type of stem cell from the skin of adult and juvenile mice.[4] The McGill scientists coaxed these stem cells to develop into neurons, smooth muscle, and adipocyte (fat) cells. This work holds twofold significance. Biomedical researchers previously thought that adult stem cells could only develop into cell types of the same tissue lineage, but these cells developed into cell types representing different tissue lineages. Though not totipotent, these stem cells manifested developmental potential beyond that of typical pluripotent stem cells. Secondly, these unique multipotent stem cells derive from the skin making them easily accessible. The human scalp may actually possess this type of adult stem cell.
Another team of scientists has recovered adult stem cells from the bone marrow of mice—cells that developed into lung, skin, stomach, and intestine cells.[5] Yet another team has isolated mouse brain tissue stem cells with the capacity to develop into nonneural tissues.[6] These studies usher in an important paradigm shift in stem cell research that may well eliminate the demand for embryonic stem cells.
Another mouse study overthrows an additional long-held paradigm in developmental biology—namely, that some tissue types lack the capacity to regenerate after injury. Investigators from the Wister Institute in Philadelphia discovered a mouse with the amazing capacity to regenerate heart muscle tissue.[7] In mammals, damage to cardiac tissue leads to the formation of nonfunctional scar tissue. Yet when their hearts were damaged, these mice displayed limited scar tissue buildup and produced replacement cardiac tissue. Understanding the molecular and genetic framework for this remarkable property holds potential for pharmaceutical treatment not only to repair damage from heart disease, but perhaps to repair damaged nerve tissue as well.
These thrilling advances, as well as new ones anticipated in the future, will likely lead to a shift in the focus of stem cell research. While continuing to oppose destruction of human embryos, the Christian community can and should aggressively support additional funding for stem cell research with the same goal as the scientific community—alleviating human suffering.
Daughters, husbands, neighbors, and nephews—loved individuals—all deserve compassion and the best of ethical research. On this common point of human dignity everyone can agree.
[1]Harvey Lodish et al., Molecular Cell Biology, 4th ed. (New York: W. H. Freeman, 2000), 1062, G-16.
[2]Scott F. Gilbert, Developmental Biology, 6th ed. (Sunderland, MA: Sinauer Associates, 2000), 98-99.
[3]For a primer on stem cell research posted by the National Institutes of Health see http://www.nih.gov/news/stemcell/primer.htm [23 August 2001].
[4]Jean G. Toma et al., "Isolation of Multipotent Adult Stem Cells from the Dermis of Mammalian Skin," Nature Cell Biology 3 (2001), 778-84.
[5]D. S. Klause et al., "Multi-Organ, Multi-Lineage Engraftment by a Single Bone Marrow-Derived Stem Cell," Cell 125 (2001), 369-77.
[6]Rodney L. Rietze et al., "Purification of a Pluripotent Neural Stem Cell from the Adult Mouse Brain," Nature 412 (2001), 736-39.
[7]John J. Leferovich et al., "Heart Regeneration in Adult MRL Mice," Proceedings of the National Academy of Sciences, USA 98 (2001), 9830-35.
After Death I.D.—Will I Still Be Me?
By Ronald Nash
Most Christians are convinced that people will know each other in heaven. This belief brings great comfort to believers as they watch loved ones pass on. But as popular as this belief may be, many Christians would be hard-pressed to produce much support for it. The tough question is this: How can Christians be sure that people will know each other in heaven? What kind of support, biblical or otherwise, can be found for the widespread belief that believers will recognize each other in heaven?
First it is necessary to establish whether humans retain their identities after death. Whether at the final judgment or in heaven, will we be the same people that we were in this life?
A good theological support for the idea that we will be the same people is based on the justice of God's judgment at the end of history. At the final judgment, every human being will be raised from the dead and stand before God. It is clear that each person God judges at that time must be identical with the person who performed the deeds being judged. How can God be just if those He punishes are not the same people who actually committed the sins? How can God be just if those He rewards are different from those whom He chose before the creation of the world and saved by His free grace (Romans 8:28-30)?
One important biblical support for the belief in personal identity after death comes from Mark 12:26-27 where Jesus said, "Now about the dead rising—have you not read in the book of Moses, in the account of the bush, how God said to him [Moses], 'I am the God of Abraham, the God of Isaac, and the God of Jacob?' He is not the God of the dead, but of the living." Jesus explained that even though these patriarchs had been dead for centuries when God spoke to Moses, God meant that Abraham, Isaac, and Jacob still existed as Abraham, Isaac, and Jacob during Moses' time. God's words further imply that these men still exist as themselves today. Abraham and the others retained their identities after death. Even after physical death, they kept the relationships with God they had enjoyed during their earthly existence. Jesus therefore assured believers that death does not end human existence or personal identity.
In Luke's account of Jesus on the Mount of Transfiguration, Peter, James, and John saw that "the appearance of [Jesus'] face changed, and his clothes became as bright as a flash of lightning. Two men, Moses and Elijah, appeared in glorious splendor, talking with Jesus" (Luke 9:29-30). Not only were these prophets still spiritually alive, but they also retained their identity as Moses and Elijah!
Additional biblical support for a belief in the continuation of personal identity after death is found in the accounts of Jesus' appearance to His disciples following His resurrection. When Jesus appeared to the disciples on the evening of His resurrection, He spoke to them and showed them His wounds (John 20:19-23). John 20:20 says that "The disciples were overjoyed when they saw the Lord." The risen Christ the disciples encountered in the upper room was the same Jesus they had known before His death on the cross.
These Scripture passages demonstrate that humans survive physical death with personal identity intact. Thus, we can reasonably infer that people will know each other in heaven.
Dr. Ronald Nash is professor of philosophy at Reformed Theological Seminary in Orlando, Florida and at Southern Baptist Theological Seminary in Louisville, Kentucky. He has published over thirty books including Life's Ultimate Questions and When a Baby Dies, many of which are available from www.amazon.com.
Creedal Controversy: The Orthodoxy of "Days"
By Kenneth Richard Samples
Should a specific view of the nature and duration of the creation days of Genesis be considered a part of the Christian creed? Does an "orthodox" position on the creation days exist, as it does for the Trinity and the Incarnation? Over the past few years a number of theologically conservative denominations (for example, Orthodox Presbyterian Church, Presbyterian Church in America, and the United Reformed Churches of North America) have discussed and debated the controversial questions of how to understand the Genesis creation days. Recently, both the Presbyterian Church in America (PCA) and Westminster Theological Seminary, one of evangelicalism's most conservative and well respected theological institutions, released statements announcing their conclusions. In light of the statement set forth by Westminster Theological Seminary (WTS), a number of reasons emerge for resisting the push to make the nature and duration of the creation days a test of orthodoxy.
Within conservative Reformed theological circles, and among conservative evangelical scholars as a whole, four popular and distinct interpretations presently dominate discussions concerning the Genesis creation days (though of course others exist). These positions include the Calendar-Day interpretation, which treats the days as six consecutive twenty-four hour periods; the Day-Age Interpretation, which views the days as six consecutive long ages; the Framework Interpretation, which considers the days as topical rather than chronological, unspecified in duration; and the Analogical-Day interpretation, which sees the days as merely analogous to the human work week. All four views appeal directly to Scripture for support. All four views are held by staunch advocates of scriptural inerrancy and supernaturalism. All four views reflect exegetical strengths and weaknesses. None of the views, however, deserves to be labeled an ad hoc capitulation to modern evolutionary theory.
More important than the exact nature and specific length of the days of creation is the factual nature of the events mentioned and described in the first three chapters of Genesis. Scripture describes a divine creation ex nihilo (out of nothing), Adam and Eve as actual historical persons, a real time-and-space fall of mankind into sin, and a divine promise of redemption. All four of the interpretations affirm, in principle, these non-negotiable biblical truths. While some of the views make a more substantial account and explanation for the biblical data than do others, the worst accusation one can legitimately levy against any is that it may sometimes be inconsistent in its affirmation of biblical truth. However, even if inconsistent, not one of these interpretations undermines the very truth-claims of Christianity through actual heresy.
Some scholars hold that any view of the creation days as other than six consecutive twenty-four hour periods must be labeled heretical, not explicitly, but implicitly. They argue that reading the days of Genesis as anything other than twenty-four hour periods undermines orthodoxy because it allows for the possibility that Earth is billions of years old. This idea, in turn, allows for the possibility of animal and plant death (not human death) before the Fall. Such an idea, they assert, compromises one or more of the non-negotiable doctrines of the faith. However, many well-respected evangelical scholars see no real logical or theological support for such an assertion. Some of these same scholars have raised doubts as to whether the Calendar-Day view itself can be squared with biblical inerrancy.
Christianity's greatest theologians and biblical scholars, including Augustine, Calvin, and Warfield, expounded a diversity of views concerning the nature and duration of the creation days. From the time of the church fathers, through the Reformation, and up to the present, various views have prevailed, some more broadly represented than others, but none was ever considered the definitive, or the only, orthodox biblical position (see the WTS statement).
If indeed the nature and duration of the creation days cannot rightfully be considered a test of orthodoxy, then for church bodies to split over such issues not only hurts the unity of believers but also damages their reputation among non-believers. Christians have a divine imperative to stand up for the truth and against false doctrine. The issues worthy of such a stand do not include the length of God's creation days. For nearly 2000 years Christian martyrs all over the world have chosen death rather than deny the essential doctrines of the faith. May God grant His church the wisdom to know which issues to fight and die for and which to acknowledge as needing further study.