Does physics explain why the laws and behaviors observed in biology are as they are?

Question: Does physics explain why the laws and behaviors observed in biology are as they are? I feel like biology and physics are completely separate and although physics determine what's possible in biology, we have no idea how physics determine every facets of biology. We know roughly how forces in physics may impact biological systems, but not every little connections and relations that exist between physics and biology. Am I wrong?
Comment: Which law of biology do you have in mind?
Comment: @my2cts there are many *lows*, which is why I initially judged the question too open-ended. To be fair to biologists, they do not often call them laws, at least not in the same sense as phsyicists. Even *The central **dogma** of molecular biology* is not 100% precise, once we discuss reverse transciption: https://en.wikipedia.org/wiki/Central_dogma_of_molecular_biology
Answer: To get more insight into a question like this, you might like to ponder the relationship between logic gates and programming languages in the case of computers. This is a lot simpler than the physics—biology question, but begins to open up some of the issues. When a computer runs a program, certainly lots of logic gates and memory elements etc. are enacting the process described by the program. But the logic gates do not themselves tell you much about the structure and nature of a high-level programming language such as Java or Python. In a similar way, further study of atoms and molecules will not in itself reveal much about the immune system in mammals, or the social structure of an ant colony, and things like that.
This "answer" is really a brief comment on what is, in the end, quite a deep issue concerning the whole nature and structure of scientific knowledge. Another useful thing to ponder is the relationship between the concepts involved when one moves from the equations of particle physics to many-body physics. There is every reason to consider that the motions of a non-linear many-body system are all consistent with the description offered by the Standard Model of particle physics for all the various fields and interactions. However, the low-level description does not in itself tell us how to formulate a field theory which correctly captures the main elements of the collective behaviour.
It is a bit like the difference between knowing the rules of chess and knowing how the game is played to a high standard. For the latter one needs to appreciate some higher-level issues such as the importance of the central squares, pawn structure, open files and things like that. It is not that these are somehow operating without regard to the laws constraining the movement of the pieces, but rather the low-level laws (about how individual pieces may move) simply do not frame a language adequate to describe the higher-level issues. This analogy with chess is not perfect, of course, but it is apt nonetheless, and it illustrates why it is quite misleading to claim, as many do, that "physics explains chemistry". The situation is more subtle than that.
For example, the behaviour of many chemical reaction networks has features which do not depend much if at all on the individual reactions, but on the global structure of the network. It is not that such networks fail to respect any law of physics, but the description at the level of individual components cannot frame a language adequate to express and thus grapple with the higher-level issues such as whether the network is stable overall, and things like that. And what is really telling is that it is very common for these higher-level languages to have internal consistency and a certain robustness, such that they can be supported by more than one underlying hardware. This is similar to the way a given computer program can run on different types of hardware as long as the operating system is in common.
Answer: Emergence
Physics does not determine every facet of biology! Biology is a great example of what is called emergence - the phenomena where the composite of many simple entities has properties that the entities themselves do not possess (and which are not always predictable on the basis of the properties of the entities).
I have already given an example in my comment (also given in the answer by @AndrewSteane) of computer programs: existence and properties of an operating system, such as Linux or Windows, is certainly dependent on the existence of the silicon atoms constituting the chip, but cannot be predicted from the properties of these atoms alone. There are many layers of complexity in between:

the atoms make a crystal
the logic gates in a chip are fabricated from this crystal
the architecture of the logic gates on a chip is not directly determined by the properties of the gates themselves
the assembler language, addressing the gates on the basic level could exist in many different versions
the same assembelr language allows for many operating systems with wildly different properties

Claiming that everything is just physics simply because physics underlies the basic processes is a logically faulty argument.
Biophysics
There is a big part of biology, dealing with the phenomena that can be directly described using physics equations. Just to give a few examples:

the molecular bonds and basic chemical kinetics
folding of macromolecules
mechanical properties of body tissues
flow of blood and other liquids
skeletal and muscular dynamics

For a deeper overview you may consult these books:

Mathematical physiology
Physical biology of the cell

I also recommend the Lectures on statistical physics and protein folding by Kerson Huang, the author of the widely used basic textbook on statistical physics. This one is a short and very readable introduction to the complexity of the phenomena involved.
Physically-inspired biological models
In some cases one uses models inspired by physics to model the biological phenomena that are not really the same as those underlying the original physics model. E.g., one uses Ising spin chains for statistical analysis of RNA structures - where the probabilities of configurations reflect not thermodynamical properties, but the frequency of these configurations in organisms, determined evolutionary rather than physical constraints. In a related example, Henry Orland has used large N expansion of the quantum field theory for classifying possible RNA structures - this is again an author of the well-known text on many-particle physics. See also this question.
Another such application is the use of the equations for drift-diffusion in non-linear potential to model decision-making by mice.
Computational biology
Many problems in modern biology are not directly related to physics, but often require the mathematical, statistical, and research skills that physicists possess - it is not therefore surprizing that many computational biologists have physics background (I am among them). One could give as examples:

modeling of non-linear phenomena in cells (e.g., a virus replication cycle can be described as switching between two distinct phases, controlled by the concentration of chemicals)
Population biology (modeling gene propagation with generations, see the Gellespie's little textbook for the serious but short introduction or the Neher and Shraiman review, which is the crash-course for physicists.)
Non-linear epidemiological equations (by now we have all see the curves that result from them, see Compartamental models in epidemiology)
Bioinformatics, i.e., analysis of biological sequences (though this requires more computational than physics skills, there is a lot of matrix algebra in it)

Biology
Still, there are a lot of biological processes that are not described in terms of just physics. E.g., the processes of transcription and translation, which form the Central dogma of molecular biology are hardly reducible to physics or even chemistry. If you come from a physics background, the biochemistry describing them leaves a indeed taste of a fairy-tale (no Hamiltonian, no equations), but it is a result of systematic observations and statistical analysis.
Update
@taciteloquence suggested in the comments a relevant quote from PW Anderson's 1972 article in Science More is Different.

The ability to reduce everything to simple fundamental laws does not imply
the ability to start from those laws and reconstruct the universe.... At each stage entirely new laws, concepts, and generalizations are necessary, requiring
inspiration and creativity to just as great a degree as in the previous one.
Psychology is not applied biology, nor is biology applied chemistry.

Update 2
As it was pointed out in connection to another question by @AndersSandbreg and @DvijDC, even if we could calculate behavior of complex biological systems from micrcoscopic physics laws (aka ab-initio simulation), this would not necessarily provide us with deeper insights into the behavior of these complex systems. Rather to the contrary, it is reducing the complex behavior to simple biological statements that gives us deeper udnerstanding (on a higher level). In this sens eit could be even claime that biology explains physics rather than the other way around.
Comment: Comments are not for extended discussion; this conversation has been [moved to chat](https://chat.stackexchange.com/rooms/122481/discussion-on-answer-by-vadim-does-physics-explain-why-the-laws-and-behaviors-ob).
Answer: Is biology an application of the laws of physics ? If you believe the laws of physics ultimately explain all physical phenomena then yes, it must be.
Are there grounds for this belief ? Well, so far we have not found any physical phenomena that definitely require something other than the laws of physics to explain them i.e. there is no empirical evidence for supernatural causes, for miracles, or for magic. And we know that biological phenomena follow regular patterns and can be investigated using the scientific method. Medicines do not come with warnings such as "will only work if you say the magic words and the stars are aligned properly".
Do we know how some biological phenomena can be explained in terms of the laws of physics ? Yes, there is a whole field of study called biophysics that covers exactly this.
Do we know exactly and in detail how everything in biology can be shown to be an application of the laws of physics. No, not yet.
Is it a problem that we don't know how exactly everything in biology is an application of physics ? No, not at all. Trying to reduce problems in biology to problems in physics is in many cases not a useful approach, even though we think it could be done in principle. By analogy, we know everything in cookery is an application of physics (since there is no magic pixie dust involved) but approaching every recipe as a physics problem will not get us very far.
Comment: Comments are not for extended discussion; this conversation has been [moved to chat](https://chat.stackexchange.com/rooms/122556/discussion-on-answer-by-gandalf61-does-physics-explain-why-the-laws-and-behavior).
Answer: To clarify some of the answers talking about emergence:

Everything in biology is explained by physics, and physics predicts all of biology.
A human who knows all of physics won't be able to use that knowledge to learn much about biology.

Some top answers right now claim that "physics does not explain biology" because biology involves "emergent" phenomena. This may be misleading. "Emergence" is a property of the person using a set of laws, not a property of the laws themselves.
When we say "a composite of parts has properties that the parts themselves do not," we mean that a human person looking at the (lowest-level) laws governing the behavior of the parts will have a hard time noticing that when you put the parts together, they follow some pattern that might be easy to spot if you watched the parts behaving together. We do not mean that the composite contradicts the low-level laws of the individual components, or that some additional rule is required to explain the composite's behavior.
Biology has a lot of "emergence," because living systems are so large and complex that no human could reasonably use the underlying laws of physics to predict their behavior. In principle, you could use particle physics to explain all of biology; in practice, that would be impossible, so virtually all useful biology is figured out top-down.
Answer: Every time this kind of discussions comes up I'm trying to remind people about the Mind projection fallacy.

It occurs when someone thinks that the way they see the world reflects the way the world really is.

We are using simplifications, abstractions and probabilistic reasoning because we are finite - our minds can only operate with a comparatively small amount of information about the world. Take for example the programming language analogy --  If we had the mental capacity to keep track of all the logic gates inside the computer, then we wouldn't need programming languages. We, humans, need operating systems and programming languages because we have to break the complexity of billions of transistors into manageable blocks.
So every time someone brings up concepts like "emergence" to explain some things, my clarification is that this "emergence" doesn't happen in the real world - it happens in our heads. (People usually don't like this clarification, though.)
Now, to answer your question. The difference between "physics" and "biology" is introduced by humans - their minds are too feeble to keep track of decillions of atoms moving around, so they abstracted some blobs of atoms into "organisms" and other such stuff. And then some (most) humans tricked themselves into believing that these abstractions are how the world really is.
Answer: Physics does not explain all biological phenomena.
The key point other answers are making excellently is that any kind of problem (even in physics) is "layered". When worrying about a gas of Helium we don't worry about the standard model underneath, and we certainly don't worry about whether there is an as-yet undiscovered theory underneath that. No one knows for sure where the "bottom layer" actually is.
Many features of a system don't depend much on the layers underneath. For example consider the theory of evolution. Is it even possible to conceive of a set of laws of physics describing some kind of universe in which imperfect replicators (life) exist that are not subject to the theory of evolution? How could they not be? [1]
The theory of evolution is saying something very strong and something essentially independent of the layers underneath. Some other example emergent laws that seem very "robust" to the actual underlying rules might be thermodynamics, and some theories in economics (if more consumers want to buy a product the price goes up: that probably is true in any universe with capitalist consumers buying products, even if the physics of those universes were completely unlike our own).
[1]: Unlimited resources might be a way to do this. If nothing ever needed to die then evolution would at least look quite different.
Comment: You're kind of missing the point here. Physics certainly does explain all these phenomena, if you needed to go down into it. What happens with your "layers" is merely that in some cases you can tolerate approximations where the error from the underlying physics happens to be small, so putting in all that extra effort wouldn't improve your result enough to matter. It doesn't mean that physics isn't in control underneath it all.
Comment: ... A good example from physics itself is Newtonian motion. It's accurate enough that it's still used for planning trajectories for space missions around the Solar System. For those applications, the error is small enough that you don't need to go deeper. It doesn't mean Einsteinian physics isn't in control under the surface, and in some applications (like GPS) the difference does matter and you do need to go that extra step further.
Comment: Up to you, but I strongly disagree @Graham.I can understand and explain evolution without knowing any physics, and the basic theory of evolution is robust against any changes in the laws of physic. You could explain the theory using the standard model maybe, but then I can give you a "non-standard model", describing some completely fictional physics, and you could probably STILL explain evolution using that other theory. In that sense evolution is "robust" it doesn't matter what physics you have, and therefore the physics isn't where evolution "comes from". It doesn't have to be a small change
Answer: Physics explains chemistry, and chemistry explains biology.
Physics explains what chemicals can be made, not what will be made. Likewise, chemistry explains what biology will work, not what will be made.
Chance explains some of biology. Some mutations happen, others do not. Some mutations are advantageous, some are not. It isn't true that every advantageous mutation spreads.
There are some aspects of biology for which we have no theory. Some of this is because the chemistry is very complex. Come back in a century, and we may know more.
The theory of the mind is only at the barest beginning. Personally, I don't have the faintest idea how sensation, emotion, and conciousness will be explained. The best I can say is "Whatever they are, they arise from the brain and I have no idea how." Religions provide answers, but the answers do not satisfy the standards of science. Many of the answers amount to "Whatever they are, they arise from God."

Edit - Comments on several answers are getting lengthy, and likely will be moved to chat soon. I have made several comments. I am moving some of them here. These are from comments on gandalf61's answer, where he says

... there is no empirical evidence for supernatural causes, for
miracles, or for magic.

My comments address limits of what physics can say about biology, or perhaps what science can say about reality.

+1, but be careful about saying there is no evidence for miracles, etc. Science is all about laws of nature - repeatable patterns of
behavior of the universe. A miracle is by definition not a repeatable
effect of any physical cause. One could happen right there in the lab,
and a good scientist would throw it out because it can't be verified
by repeatable experiment. Not to say that miracles happen in the lab
or elsewhere. But science has no evidence because by design science
does not consider that kind of evidence or include that kind of
artifact in any theory.

Science has no evidence for or against miracles. The lack of evidence
is to be expected, and is not evidence for or against the existence of
miracles. Science can't take a position on the question because it
doesn't look for evidence.

However, science can take a position on other religious questions,
such as the effectiveness of faith healing. Here a healer asks God for
healing. We can measure if healing takes place and compare to similar
cases where nothing is asked. I have heard of serious consideration
about such a clinical trial. There are difficulties. How does one
arrange a double blind trial, where neither healer nor patient knows
if genuine or placebo prayer is being offered?

There are places we could look for things that have
no natural cause. Messages encoded in the digits of pi. Patterns in
quantum randomness. There are also areas where we have found strong
patterns - natural laws - without being able to anything about their
cause. I am not arguing for or against anything supernatural. Just
trying to clarify the limits of science.

Any valid long English text encoded as ascii or whatever you specify
in advance found early in pi can be your possible message. You can
limit acceptable messages so the odds are you will not find one. You
might find a message in French and throw it out, and thus fail to
discover something valid. Or you might accept it, and maybe discover
nonsense because you have violated the confirmation bias limits. Or an
English message might be valid or invalid. Or there might be nothing
to discover. You can arrange so that if you find something, the odds
are it isn't chance.

If you do find something, the process doesn't tell you if it is
unusual luck, great wisdom, a great lie, or something else.

Graham raises some points.

... it is absolutely correct to say that we have no evidence for
miracles. The main issue is the "any physical cause" part. In all
experiments, the biggest problem is isolating the many other potential
physical causes from the one(s) you're investigating. Every experiment
already has a repeatable source of "miracles", which is the rest of
the world injecting noise which gets past your experiment design.

However science can take a position on "we know there are these things
which would cause exactly this" or at least "we may not know the cause
but we have repeatedly seen this happen occasionally". So science
certainly can say that something is not a miracle, only a
low-probability event. More than that, it must, because if you
attribute anything at all, ever, to divine intervention then you
destroy any possibility to investigate a physical source. And that is
directly opposed to rational thinking. We have historical proof of why
this is wrong.

Your problem there is confirmation bias. If you have a sufficiently
large random sample (such as, hypothetically, the digits of pi), then
any encoding you care to pick (maybe ASCII) will eventually find a
string of digits which produce the message "I'm God and I'm a black
woman. Fix the Sistine Chapel ceiling.". Just for an example. It's
equally likely as the encoding producing
"zadfafhtyuweljhbgjkfyfqemgeghrhdf", because that's how probability
works. The risk for miracle hunting is that you find something because
you're looking for something without knowing exactly what.

My point is that you have to say beforehand what message you're
looking for. If you can't do that, then you can't calculate odds,
because that would be asking "what's the probability of finding
something I've already found?" to which the answer is "exactly 1,
because you've already found it". But if you can predict it then by
your definition it's not a miracle, so you'rea bit stuck there.
Comment: Just to say the situation with religion is more complex than I think you may be aware. Shallow or lazy forms of religious commitment are indeed uneasy with science and are intellectually substandard. But the kind of religious commitment that is more carefully thought-through, such as for example that of James Clerk Maxwell or other leading physicists, both understands, respects and celebrates the role of science. This kind of religious commitment relates to science somewhat as do qualities such as honesty, humility and curiosity: they are not science, but they motivate, support and enable it.
Comment: @AndrewSteane: I think you may be reading more into mmesser314's answer than intended. The way I read it, they're merely saying that _religion-based explanations of mental phenomena_ such as sensation, emotion and consciousness _do not satisfy the standards expected of a scientific explanation_ (such as falsifiability and the ability to make testable predictions). Which is reasonable enough, as that's not what they're supposed to be in the first place.
Comment: @IlmariKaronen thanks for this remark which is friendly to all parties. I see what you mean but I also hope my comment will be helpful anyway.
Comment: @AndrewSteane - I am not implying shallow or lazy. I meant nobody has any explanation of the mind that includes a detailed enough mechanism to make me think they understand how the mind works. Freud made the first attempt to understand the structure of the mind with ideas like id, ego, and superego. But that is no more successful than fluxes and humors were in explaining medicine, or phlogiston in explaining heat. Nobody has explained the mind from first causes.
Comment: @IlmariKaronen - Thank you. I should have been more explicit.
Comment: How do you explain the feeling of pain or love? Even if you knew in detail the elementary particles' positions and velocities, then you still wouldn't be able to explain these feelings.
Comment: @DescheleSchilder - I understand what you are saying. But I don't know enough about what explanation will turn out right to agree with even that much. For example, there are obvious differences between alive and dead, even in plants. Before biology was based on chemistry, explanations were religious. Now we find that chemistry can explain it.
Comment: @Deschele Schilder It is relatively easy to come up with a scientific definition of the state of pain or love. But such a definition is only useful if people *agree* on it, which, of course, it is unlikely many would, which is why scientists choose different words to describe related phenomena (e.g. the various terms for nervous system phenomena).
Answer:
I feel like biology and physics are completely separate

For where biophysics is heading, and due to the distinction that is arising between "biophysics" and "physics of living systems", I think the idea that it goes physics $\to$ chemistry $\to$ biology is no longer the case (if it ever was). People are actually using biological systems to learn more about physics now. So these fields are actually deeply connected: many biological problems now require physics (either directly, or at least in application of its principles, techniques, concepts, etc.), and many biological systems can be/are used to learn about physics.

although physics determine what's possible in biology, we have no idea how physics determine every facets of biology.

It is true we do not have a complete knowledge of the physics of living systems. But we still have ideas as to how they are connected and applied.
Onto the title:

Does physics explain why the laws and behaviors observed in biology are as they are?

While my answer has claimed a strong link between physics and biology, there are of course distinctions. The statement "laws and behaviors observed in biology" is very broad. In physics, we all know the same principles; undergraduate physics education is essentially, "here are all of the principles of physics", and then if you go further into research you are essentially learning what those principles do in the universe. But if, say, a particle physicist wanted to talk to a solid-state physicist, they could still assume knowledge of the same base ideas in order to further understand each other.
In biology, it is somewhat the opposite. The field of biology is so vast and covers so many systems that there isn't really a shared set of underlying principles all biologists use. Someone working in developmental biology in the fruit fly will not be able to use their principles to determine what is going on with a biologist who is studying the interactions of species within some ecosystem. Just look across the answers to this question: there are so many areas of biology to consider, and they each have their own principles.
So while at the surface one can take the easy way out and say, "well, everything in the universe has to ultimately follow physics", if we dig deeper then we really need to be careful about what we mean by "laws and behaviors observed in biology". I might argue that there isn't a well-defined set of biological principles to even start exploring this question. (Although attempts are being made, e.g. William Bialek's book Biophysics: Searching for Principles)
Answer: What would a physics explanation of the mating behaviour of a bowerbird would look like, and who it would be useful to?
Biology is, in principle, reducible to fundamental physics but even if you were to solve any meaningful biological question in those terms - which is way beyond current abilities - the answer would get would have the wrong framing and explain at the wrong level. The meaningful answer for the bowerbird's wonderful mating ritual is one grounded in evolutionary theory not one grounded in particle physics.
Comment: Quantum biology is a field that is starting to get some traction. But in any case I don't think the only way to reduce something to physics is to take it all the way to the quantum/particle level. Certainly physicists were doing physics before quantum mechanics was even thought of. But I suppose that is the go-to for many people: physics = either quantum physics or astrophysics
Comment: *even if you were to solve any meaningful biological question in those terms - which is way beyond current abilities - the answer would get would have the wrong framing and explain at the wrong level.* This is incorrect. Many biological problems have appropriately been solved using physics.
Comment: @BioPhysicist: You clipped the relevant part from that quote "reducible to physics" that I intend that comment to refer to. It's certainly true that useful biological questions are answered by physics, but they're not reductive in their approach. Physics will tell you a great deal about nerve signalling if you consider membrane potentials, for example, but fully describing a membrane by reducing it to quantum mechanics is impossible.
Comment: @BioPhysicist: I don't think physics is either quantum physics or astrophysics, but I do interpret the term "reducible" as an end-point description at the lowest available level. It seems you don't? I have edited to specify "fundamental physics".
Answer: Every biological system is comprised out of zillions of elementary particles. Each of these particles interacts with a fraction of the others. Every interaction can be accounted for with the help of elementary particle physics. So yes, every biological system can be accounted for in a physical way. You and I are huge collections of elementary particles having this conversation.
What physics, or chemistry, or biology (evolution conforming to the gospel according to "Sir" Richard Dawkins), nor psychology, or whatever -y, can't explain is the Nature of the soul, or the colors you see, the sounds you hear, the feelings you feel, the shivers you experience, the itch that itches, the pain that hurts, the aggression that haunts you, the love that moves you, the cravings that come along, the hate inside, the fear that freezes, the longing to win, the disappointment of losing, the mourning, the screaming that stops at your mouth, etc. How will you explain the feeling you feel when listening to your favorite music? This can't be explained in terms of physics. For, who knows the Nature of elementary particles as described by particle physics? Let alone of zillions of them interacting.
Comment: this is a physics website, there should be no place for concepts like the "soul". It is not because we are very far from explaining perception of colours, consciousness etc now that you have to qualify categorically as it can not be explained by physics. Think about the advances science has made since the Greeks. They would have said natural science cannot explain this and that it must be something extra. Science has been chipping away relentlessly the "explanations" of religion. Never say never.
Comment: @Oбжорoв Then the question shouldn't be asked.  How do you want to explain pain? There is definitely a physical correlate in our body and brain if I experience pain. This doesn't explain the awareness of pain though.
Comment: I don't know why you're pretending Richard Dawkins has a knighthood; he's never likely to get one from the head of the Church of England. In any case, evolution is not according to him, nor according to millions of scientists worldwide. Rather, it is according to mountains of evidence. Please read [book-length](https://amazon.co.uk/dp/055277524X) [treatments](https://amazon.co.uk/dp/0199230854) of said evidence.
Comment: You are right about the sir-thing. I mixed Dawkins up with Popper. I don't know why. Maybe, unconsciously, I see that there is no big difference in their thinking. The book you refer to (it's on my bookshelf!) seems like a bible to me, All books that our friend has written have the same content. No matter how much examples given, it's just an interpretation of the facts. Genes and memes **are** passed on to the next generation, that's a fact. His interpretation? i don't like it!
Answer: @Andrew Steane provided a really good answer. For further insight into his line of reasoning as I understand it, I would recommend reading Chapter 1 of Information Theory, Evolution, and the Origin of Life (2009) by Hubert Yockey.
Yockey writes:

The laws of physics and chemistry are much like the rules of a game such as football. The referees see to it that these laws are obeyed but that does not predict the winner of the Super Bowl. There is not enough information in the rules of the game to make that prediction. That is why we play the game. Chaitin (1985, 1987a) has examined the information content of the laws of physics by actually programming them. He finds the information content amazing small.
The reason that there are principles of biology that cannot be derived from the laws of physics and chemistry lies simply in the fact that the genetic information content of the genome for constructing even the simplest organisms is much larger than the information content of these laws (Yockey, 1992).

Bolded emphasis at the end is mine. While I have not read significantly further to really justify all of Yockey's claims, I think the spirit of his ideas is in the right place, and aligns with what Andrew was saying: just like you can't use the concept of a universal computer to specifically predict what programs will be written on it, you can't use physics to predict what the specific rules of biology will be. At best, you can only constrain the rules of biology to physically-possible scenarios.

Edit: Let me clarify what I was saying in the above answer. (tl;dr: Everything depends on how you define life, and, in my opinion, the question of how best to define life is not a physics question, although it can be guided by a physics understanding.)
I'm going to use the following definitions for "physics", "biology", and "life".

Physics: A question can be answered by physics, if it is of the form: "If X occurs, will Y happen?" In other words, physics discusses possible physical scenarios and processes, contingent on a set of physical constraints. Unless we're being speculative, the physical constraints match those of the real world.
Biology: The field of biology answers questions, sometimes quite high-level ones, about the physical processes involving living things.
Life: Now, this definition is up for discussion! (Which is my entire point.)

We can choose a physics-dependent definition of life -- e.g. "A living thing is a localized collection of carbon and other atoms with X additional properties" -- or we can attempt to produce a relatively physics-agnostic definition of life (which Yockey attempted to do -- the question of whether his definition is a good one is a related, but different, matter).
If you choose a physics-dependent definition, then, yes, you can generally determine several biological rules -- but even then, not all of them, due to emergence, which others have mentioned. These physics-dependent definitions of life often run the risk of being too specific (e.g. too carbon chauvinist) -- we might have to expand the definition of life when we encounter new forms that we decide we want to be considered as alive.
However, I was merely noting that some people, including Yockey, have tried to produce relatively physics-agnostic definitions of life, which are of at least some epistemological interest (even if of little to no biological interest). I worry that Yockey's definition, which is based on information processing principles, runs the risk of being too general -- it is hard to see how computers, for example, would not be lumped into his definition of life. More generally, if several very different physical systems match a physics-agnostic definition of life, it is hard to argue that physics alone "predicts" how life ought to function: it simply constrains how life does/can function in our universe.
But, in my view, exactly how you define "life" is not a physics question (it's a biology question), and because the set of allowed biological processes is strongly dependent on how you define life, I would hesitate to say that physics predicts "why the laws and behaviors observed in biology are as they are". As others have mentioned, even if you a priori choose a physics-dependent definition of life, as we already know on Earth, living systems adopt a wide variety of behaviors, none particularly dependent a priori on the laws of physics, but just as much as on circumstances, history, hysteresis, and emergence.
Comment: *you can't use physics to predict what the rules of biology will be.* I greatly disagree with this statement. Physics is used in many areas of research to determine how biological systems will behave.
Comment: Could you give some examples?
Comment: @BioPhysicist I was a bit brief, which led to confusion. Once you've defined what biology is, then you can use physics to predict how biological functions will evolve. But "biology", as a word, doesn't have any inherent meaning: we could define "biology" to mean "how rocks fall," for example. But nonetheless, if we instead say the typical thing, that "biology is the physical process of life", then we are constraining biology to follow the laws of physics and reproduce, at least at some level, what we generally understand life to be.
Comment: @viral The square cubed law is one.
Answer: We are very good at describing small quantum mechanical systems, because today we have QM, and we do know that the world is ultimately quantum mechanical in nature. That being said, when it comes to predicting bigger biological systems (just like our own human nature), our capabilities are very limited. We are all made up of QM systems, elementary particles, who are reading this question, but if we would ask a question like, "can you explain why you are asking this question at all", then explaining it based just on QM is not possible. There are two main reasons for that:

though we are very good at describing small QM systems, the task becomes extremely difficult for larger systems

What are the primary obstacles to solve the many-body problem in quantum mechanics?

biology adds something extra, you can call it instinct, consciousness, life, nature, whatever you want, but it is governed by a biological program, and described by a programming language, the DNA (this about the programming language is nicely described in @andrewsteane answer). We are in babyshoes at describing biological system's behavior based on DNA, but in the future we might be able to do so with much more efficiency.

https://en.wikipedia.org/wiki/DNA_computing
So the ultimate answer to your question is that biological systems are qualitatively more then just a "bunch" of elementary particles.


FTAP a-la Harrison, Kreps and Pliska

Question: I was reading the papers co-authored by Harrison, Kreps and Pliska, that initiated the formal research on the connection between pricing, martingale measures, arbitrage and completeness. I have some issues relating some of the ideas, though, and would be happy if somebody could help me.
In a more or less abstract setting, one considers an ordered topological space $X$ of cash flows, a subspace $M\subseteq X$ of traded instruments and a positive linear functional $\pi:M\to \Bbb R$. The 1st FTAP that relates absence of arbitrage to the existence of EMM concerns continuous extension of $\pi$ to $X$ which is still positive. As an example, one can consider
$$
  M = \left\{m = m_0 + \int_0^T H_t\;\mathrm dS_t \right\}
$$
where $H$ is some "good" strategy and $S$ is a vector of traded assets. In such case, one defines $\pi(m) = m_0$ as an initial cash endowment required to get $m$ at the maturity time $T$.
I guess, the existence of a unique positive extension of $\pi$ to the whole $X$ implies the completeness of the market: that is, we can price everything in a consistent way and there is a unique way to do this. Apparently, this automatically leads to the representability of any $x\in X$ as $x_0 + \int_0^T H_t \mathrm dS_t$.
At the same time, I do not understand, how the existence of at least one continuous positive extension may be related to the absence of arbitrage. That is, I would imagine an arbitrage being rather existence of two strategies $H'$ and $H''$ such that
$$
  m'_0 + \int_0^T H'_t\;\mathrm dS_t = m''_0 + \int_0^T H''_t\;\mathrm dS_t
$$
with $m'_0 \neq m''_0$. But this rather says $\pi$ is not uniquely defined even on $M$ instead of it is not possible to extend $\pi$ to $X$. Does that mean that the latter two statements are equivalent?
Comment: could you please link the paper?
Comment: @user8: I meant [this one](http://www.sciencedirect.com/science/article/pii/0304414981900260)
Answer: See http://kalx.net/ftapd.pdf for a rigorous proof of the FTAP accessible at the masters level.

FTAP a-la Harrison, Kreps and Pliska


LaTeX editing discussions that are editor specific

Question: Will it be appropriate on this forum to discuss LaTeX editing issues that are editor specific? For example, the two responses to this question are Emacs specific. While AUCTeX and RefTeX make Emacs-based LaTeX editing a dream, I imagine that the majority of the community might not be interested in arcane discussions of font customization in AUCTeX to make things like nice, etc., etc.
Answer: For any given question, the majority of the community will not be interested in it. Everybody has their own particular interests that generally span only a small part of the topic area of the site. So I'm inclined to say that editor-specific questions are okay, as long as the question relates primarily to *TeX and is not just a general question about an editor that someone happens to be using for *TeX editing.
Editor-specific answers to an editor-independent question (as in the example you linked to) are kind of a separate issue, but I'd say they're also okay. Some people will be amenable to using any editor that gives them access to a particular feature.
Comment: Yes, as long as it's useful to someone, answers are ok. An answer about an obscure editor that is useful to fewer people will probably get fewer upvotes, but that's the way the system is intended to work.
Comment: @ShreevatsaR: Of course, that would assume that the question was not about the same editor. In any case, I'll keep this in mind before I post any answers involving acme(1) or sam(1). (Of course, I'd also have to learn Plan9...)


Is there an ayah or hadith which indicates humans were created out of loving-mercy (Rahma) of Allah?

Question: Is there an ayah or hadith which clearly indicates that us humans were created (other reasons being as they are) out of Mercy of Allah?
Comment: Why do you think we were created out of mercy?
Answer: Apart from the verses that mentioned the causes of creation — being a test for humans and jinn (11:7) to see who among them would worship Allah (51:56) and who would not — there is no verse in the Qur'an or an authentic hadith that I know of that stipulates or insinuates that humans were created out of Allah's mercy, and Allah knows best.
Answer: This answer relies on Shia sources.
Allah swt in the Quran states two reasons as to why He has created us:

To get to know Him and worship Him
To show and give His mercy

And I have not created jinns or human beings except to worship me. I
  do not want from them any sustenance or to feed Me. (51:57)

Imam Sadiq quotes Imam Husayn saying "To worship Me" means "to be able to know Me" and eventually "get close to Me" .
أبي عبدالله ع قال: خرج الحسين بن علي على اصحابه فقال: إن الله عز وجل ما خل العباد الا ليعرفوه، فإذا عرفوه عبدوه، فإذا عبوه استغنوا بعبادته عن عبادة من سواه
Truly God the Almighty has not created His servants except to know Him so when they know Him they will worship Him. When they worship Him they will not need to worship anyone else.
<code>(Al-Mizan, vol. 18, p. 390)
</code>

Had your Lord wished He would have made mankind one community; but
  they continue to differ. Except those on whom your Lord has mercy and
  that is why He created them and the word of your Lord has been
  fulfilled: 'I will surely fill hell with jinn and humans, all
  together.' (11:118-119)

Imam Sadiq  was asked by Abu Basir about the meaning of this verse and he replied:
خلقهم ليفعلوا مايستوجبوا به رحمته فيرحمهم
God created man so that they do something to deserve His mercy and then He would give them His mercy.
<code>(Al-Tawhid by Saduq, p. 404)
</code>
Further reference.
Comment: You could give an unique answer, because I see something that it almost like my answer.
Answer: Answer:
In the name of God, We praise Him, seek His help and ask for His forgiveness. Whoever God guides none can misguide, and whoever He allows to fall astray, none can guide them aright. We bear witness that there is no one (no idol, no person, no grave, no prophet, no imam, no dai, nobody!) worthy of worship but God Alone, and we bear witness that Muhammad (saws) is His slave-servant and the seal of His Messengers.
God Says:

"We created them not except with truth (i.e. to examine and test those who are obedient and those who are disobedient and then reward the obedient ones and punish the disobedient ones), but most of them know not" [al-Dukhaan 44:38]

God Almighty Says:

"And I (God) created not the jinn and mankind except that they should worship Me (Alone)" [al-Dhaariyaat 51:56]

It is clear that He Made us so that we can worship Him( Alone) and He wanted like this so that He can test us in deeds to see which one of us is the best in deeds.
prophet Muhammad( peace and blessings of God be upon him) said:

"The one who repents is like the one without sin."
"If you did not commit sins and turn to God seeking his forgiveness, then he would replace you with another people who would sin, ask God's forgiveness and he would forgive them."

So it is clear from this that, it is one of the main reasons to why God created everting including us. Because, it is His decision to create us. I will provide you another example.
God Says:

"Whoever brings a good deed, shall the value of ten like it. And whoever brings an evil deed will be punished with one like it. And they will not be wronged." [Al-Qur'an 3:160]

The purpose of this life is the worship of God, this life is a test. A test for us, will we worship God, or will we forget Him. This is where our focus has to begin. However, the Almighty is not in need of human worship. He did not create human beings out of a need on His part. If not a single human worshipped God, it would not diminish His Glory in any way, and if all of mankind worshipped Him, it would not increase His Glory in any way. God is Perfect. He alone exists without any needs. All created beings have needs. Consequently, it is humankind that needs to worship God. Because, God Almighty Says:

"[He] who created death and life to test you [as to] which of you is best in deed - and He is the Exalted in Might, the Forgiving." [Quran, 67:2]
"Indeed, I am God.  There is no deity except Me, so worship Me and establish prayer for My remembrance." [Quran 20:14]

But that doesn't mean He needs our prayers, because it is something that God Almighty Said:

"Indeed, God is free from need of the worlds." [Quran 29:6]

Therefore, God does not need us to worship Him at all.  He gains nothing from our worship, and our lack of it takes nothing away from God.  We worship God because—through God's wisdom and mercy—He created us that way.  God made worship good and beneficial for us, from both a worldly and spiritual perspective.
Why do we worship Him? Because God Says:

"If your Lord had pleased, He would have made all people a single community, but they continue to have their differences—except those on whom your Lord has mercy—for He created them to be this way." [Quran 11:118-119]

God creating us to worship Him was inevitable.  His perfect names and attributes were going to manifest themselves.  An artist inevitably produces art work because he has the attribute of being artistic.  By greater reason, God would inevitably create us to worship Him because He is the One worthy of worship.  This inevitability is not based on need but rather a necessary manifestation of God's names and attributes.

"Say, "He is God , [who is] One, God , the Eternal Refuge." [Surah Ikhlaas, verses 1-2]

Conclusion: it is Because God wanted that way to happen. And He wanted that This life to be as a test for every sentient being He ever created. And it is His decision that we exist so that we can know Him.
Whatever written of Truth and benefit is only due to God's Assistance and Guidance, and whatever of error is of me. God Alone Knows Best and He is the Only Source of Strength.
Comment: The question says: "Is there an ayah or hadith which clearly indicates that us humans were **created out of Mercy of Allah**?" Your answer doesn't address this point at all.
Comment: @Medi1Saif Oops, sorry.
Comment: @Medi1Saif Well,  I will edit it few minutes later.


Can using red/scarlet in a design distract users?

Question: The colour red is usually associated with "danger" and "you're about to do something dangerous." What should you look out for if you're planning on a design that is primarily focused around the colour red? Also, in that case, is red still a "correct" colour for warnings?
Answer: @DA1 has pretty much covered the main aspect that it would depend on the context i.e. a red call to action to button might stand out more strongly and convince people to click it as opposed to one with a lighter shade.

His second point about branding is also spot on.
Another aspect I would recommend that you consider is that you should also look at the meaning of red from a cultural/regional perspective.What might be used as an indication of danger or evil in some cultures might actually have the exact opposite effect in other cultures

10 Most Commonly Used Colors In Web Design And Their Examples - Interesting article on different colors being used and their impact from a design and emotional  perspective
Comment: Very good point about the culutral aspect of color interpretations.
Comment: +1 for interesting links, even though I do not understand why this is marked as answer instead of the answer posted by @DA01.
Answer: Red is often associated with alerts/warnings, but it doesn't have to exclusively be associated with that. If your site is primarily red in theme, then you can certainly pick out other colors to serve the purpose of alerting users.
Take a look at Target's web site. Red is their primary branding tool and, as such, a huge part of their site's UI. They then use other colors as their secondary emphasis colors (such as the sky blue for product links).
Answer: It much depends on the context and the surrounding colors. Here's a comparison of two red buttons, in very different surroundings.
Like DA01 already commented, red doesn't exclusively need to be associated with alerts. Some other examples: ColoCola red, red light district, red roses, etc.


Facebook functionalities in people hub

Question: The people hub is really good and the integration of Facebook and twitter is just great. The hub is so good that its restraining me from installing the dedicated Facebook app.
But since both exists in the app market and both developed by Microsoft, there might be some functionalities left out in the people hub for Facebook.
Please help me pin out the functionalities that Facebook app has at offer and people hub doesn't.
Answer: I prefer the Facebook app over the people hub for day to day FB interaction. People hub only notifies you of alerts on your wall or from people you mark as close friends. The Facebook app lets you see your full feed. Also, you can't like an individual comment on the People Hub. Finally, it let's you browse your friends profiles and brings more of the features of the full website.
There are some things you can't do on the app that the website allows like changing your profile picture and cover picture.
Comment: From memory, only the app allows other important things such as Approve/Add friends and Send Direct Messages?
Comment: One can change the profile picture via hub. Only the cover can't be changed. Also there is no difference in the post if U don't explicitly set the hub to display just the in-phone contacts
Answer: In addition to the other answer[s], you can't read private messages with WP7 either.

Facebook functionalities in people hub


how to route traffic to other computer via firewire, everything else via wifi

Question: I have two macbook pros connected via firewire.
Both are also connected to wifi.
How can I check that traffic between the two computers is going preferentially via firewire, but everything else goes via wifi?
Answer: You will need to control this using network routing.
If you assign an IP address on a different subnet as the WiFi to both computers on the FireWire link - you will ensure that traffic between the two computers will be restricted to the wired network.
You can see the network routing tables by opening the Network Utility and you can control the IP address of both firewire interfaces using the normal network preference pane.


Can I run a Greengrass Core and an IoT Device on the same machine?

Question: We are trying to create a system that reads and performs some computation on data coming in via serial port (from a CAN network) and send the results to the cloud. I have been looking into AWS Greengrass and am wondering if it would be possible to create a device that does the processing/sending results to the Core, AND a Core that forwards the results to the cloud on the same machine (e.g. a Raspberry Pi)?
Answer: AWS Greengrass is designed to do IoT processing at the edge, rather than (or in
addition to) sending it to the cloud.
So, if you want to do some processing of your data at the edge, you can use any
IoT Edge platform that fulfills your requirements. If Greengrass, Amazon documents
where this runs. We have only tested it under Intel Linux.
Else, if you just want to forward the data to the cloud, then you just want a
"gateway" functionality that packages the data that your device is generating into
the format that your cloud platform wants. That is usually MUCH less effort than
integrating with an edge platform.
Answer: I'm not super familiar with Greengrass, but I'm assuming it's similar in design to Azure IoT Edge. Where IoT Edge runs Docker to manage local "modules", it sounds like Greengrass takes Lambda functions which from my understanding could fulfill the same need. Have you looked a creating a Lambda function to read the data stream, format it and publish it? Looks like Lambda supports common languages like Python and Java.
I doubt Greengrass Core was designed to run side-by-side on a single device. I imagine it's theoretically possible, but I would look first at how it was designed to be used.
It looks like they also support something called "Connectors" so they may already have a CANBUS connector?
https://docs.aws.amazon.com/greengrass/latest/developerguide/connectors.html


Using sources multiple times in a paper in different places--how to cite

Question: I'm writing a paper for National History Day in my Social Studies class and am using MLA formatting. It occurred to me that I had a lot of differing information from some sources, such as a historical novel. How would I cite it if I put information from the same source into the paper in varying parts? Should I, instead, figure out a way to put it all together at once per source?
Answer: The reference is abbreviated to the minimum required to clarify the source. For example, the work first referenced as:
7 Jane Doe, "Infinitely Anonymous," Every Knows My Name, 2nd ed., I Am Jane Doe (New York: Jane Doe Publishing, 2016) 42-43
on the second and subsequent reference would become either:
8 Doe 45  (if you use only one book by that author, or)
8 Doe, Everyone 45 (if you use multiple books by the same author.)
It used to be customary to use "Ibid." (short for the latin for "in the same place") or sometimes "op. cit." ("in the same place") for a subsequent reference, but I understand that the MLA no longer recommends that.
You might want to check college and university websites, which frequently have 'how-to' instructions on whichever kind of citation they use. MLA is common enough that you should be able to find a number of places.


Why don't I get my reputation back if nobody answers my bounty question?

Question: I think the title says it all.
Whats up with that?
Answer: Otherwise you receive all the benefit of promoting the question, at no cost.
Thus, every question should be bountied, all the time, so the bounty concept would become meaningless.
https://askubuntu.com/faq#bounty
Comment: "all the benefit"... except somebody to answer the question. Bounties shouldn't expire until the question is answered IMO. And they should accumulate point-interest the longer nobody answers it.
Comment: But bounties are auto-awarded at a relatively low threshold (+2, I think); I think many bounties placed would have a cost because of that.  Plus it's not like you can set more than one bounty at a time.
Comment: @Oli: I think not allowing bounties to expire might work, but allowing them to gain interest would almost give people an incentive not to answer - let it languish a little while so that it's worth more.
Answer: (The other 2 answers have talked about the system, I'm just going to give some tips on how I would have done this since it took me a bit to figure it out)
I assume you're talking about this question, which you posted a bounty on but only got 2 responses. When you bounty a question it puts it in the featured tab, which is only half the battle.
The other half (and I would consider the important part) is continuously improving your question. You've responded to two of the answers, but in the comments. What you could do is update your question with the things you've tried. Did anything come out of Dylan's recommendation? The vbeinfo feedback could have been integrated into your question that you've tried that. Have you found anything in your google searches that could maybe cast some light into this? What kind of video card is it?
Every time you update your question with the information right up front this bumps the question to the front page (and with a nice unmissable orange 50). This gets your question more visibility, and more tips.
As you improve your question it makes it easier for the next person to help answer it. The people with the now-out of date answers will either update with the next thing to try or delete their now-not-so-useful answer.
I tend to upvote questions that are always being improved because hey, maybe I don't know jack about high rez CLI, but I'll gladly upvote someone who is continuously improving their question.
So in short; consider your bounty like an power up in a video game, it helps but not by itself.
I've tacked on a bounty to the question, now we can use what we've learned and continue on and (hopefully) be a great example of how to collaboratively solve a problem.
Comment: I was a bit mean in one of my problems/questions. I gave out 50 bounty for solving my problem. When none did, I answered it myself and gave the bounty to myself. If none of the people can answer it then they shouldn't have the credit! :)
Comment: Any ideas for how to improve questions in general? I have a question (http://askubuntu.com/q/111892/8724) that I've googled for answers to, I asked another question about a possible solution that I don't know how to effect, but I'm short on ideas—hence the question. Was it simply not a good question to put a bounty on?
Comment: I think you're just stuck in a situation that isn't easy to answer.
Answer: When you create a bounty, the rep is deducted immediately, regardless of whether the question is answered or not.
Comment: Well, I guess the "bounty" is more about giving you extra priority by providing it on the front page. So you must "pay" for that, it's not about the answer itself. It's like advertisement on a web page: even if nobody clicks on the ad, people who wanted to advertise something had to "buy" the place that ad is shown. I am not related to the askubuntu.com team or such, but I guess this is the answer: bounty "fee" is about handling your question with priority (like showing it on the front page) and it's nothing about the answers. This is my _idea_ on the topic, let me to know if I am wrong.
Comment: But if nobody supplies an answer and the time expires... why don't I get it back?
Comment: The moment the bounty is created - not awarded - the rep is gone for good. This is the case whether or not you receive responses, and regardless of whether the bounty is actually awarded.
Comment: @LGB I recommend posting that as an answer! (And I'm [not alone](http://chat.stackexchange.com/transcript/message/5483067#5483067).)


Who & When composed the prayer said prior to calling the Kohain to the Torah?

Question: In this question and answer Why are there different intro. prayers for calling the Kohen aliyah on Shabbat vs. weekday? there seems to be a question remaining as to when the prayers of ותגלה ותראה עלינו בזמן קרוב and ויעזור ויגן ויושיע which are said to call up the Kohain was composed. Who composed these prayers and in what time period were they composed?
Comment: Almost none of our prayers have definite dates of composition or definite authors. Perhaps you should ask this more generally about the origin or these prayers
Answer: Beurei Hatefilah mentions two versions emanating from Siddur Rav Amram Ga'on , which includes an overall longer version than the version found in Art Scroll / Birnbaum Ashkenaz (Some siddurim include parts of Rav Amram's version esp. for Shabbat pre-Kohen aliyah.) You will notice that his version has mainly psukim and just the last, brief words of הכל הבו גודל לאלקינו ותנו כבוד לתורה. (Sidebar - very poetic, but curious why the first word is הבו and the 2nd is תנו - both mean "give".)
The other version, from Machzor Vitri mentions the phrase, תגלה, etc. Interestingly enough, he mentions to say this on Shabbat Shacharit.
I can't say where the shorter version that Ashkenazim now use on Shabbat staring with ויעזור comes from. Perhaps, I can locate this, and if so, will edit, later.
If you can, read the whole article as much of it explains Talmud Baba Kama as to not just why the Torah is read specifically on Mon. & Thurs. & Shabbat afternoon, and how the concept of saying any prayers before Torah reading began.


What are some good, free tools to run automated security audits for PHP code?

Question: I've been looking for some time now and have come up short. The most promising I found was Spike PHP, which seems to no longer work. I'm looking to scan my code for potential risks of SQL Injection, XSS, etc. I've gone through most of my code manually, but with a few hundred thousand lines of code, I'm sure I missed things. If possible, are there any tools that can be downloaded and analyze code on my local machine rather than installing to the live server (this isn't a requirement if not)?
Comment: Take a look at skipfish from Google. It doesn't focus on PHP but it will attack your code.
Comment: From what I was reading it would run on the server and could disrupt service, which isn't an option since this isn't something that is in development, it is on a live site.
Comment: Voted to close as duplicate. Really, there are a lot of similar items here: http://security.stackexchange.com/questions/10/how-to-perform-a-security-audit-for-a-php-application, http://security.stackexchange.com/questions/1088/scripting-a-search-through-php-files-for-dangerous-calls-for-manual-review, http://security.stackexchange.com/questions/32/what-tools-are-available-to-assess-the-security-of-a-web-application
Comment: I do think this is a duplicate, however as it has been migrated across I think leaving it open for a while but moving @Ams comment to an answer might help the original poster see the other questions.
Comment: Sorry, I didn't realize one had been opened for security until this question got moved from Server Fault.
Comment: Skipfish can destroy your server. It can be run from any command line against any command line. You can also throttle it so that it doesn't beat up your server. I still think you should try skipfish
Answer: There's a static code analysis tool for PHP called RIPS.  I've not had the chance to use it as yet, but it sounds like it's in the right kind of area for what you're looking to do.
On the commercial tool side of things, Fortify SCA has support for PHP, as far as I know.
Answer: Check out YASCA. From their own site: it's a "glorified grep script" plus an aggregator of other open-source tools". I've had some success with this discovering security issues is the past, although I'd have to agree with the previous post that the commerical alternatives I've tried really are a couple of moves ahead.
Answer: Unfortunately, the free tools aren't that great; they're pretty limited, not so easy to use for a security novice, and/or have only limited coverage of potential security issues.
You could look at free web pentesting tools, e.g., Burp Suite.  For more recommendations, see, e.g., the following questions on this site: security assessment, pen testing tools.  However realize that they have limited coverage and will miss many vulnerabilities.
Answer: AppScan Source, a commercial tool from IBM, also has support for PHP.
Comment: The original question asks for *free* tools.
Comment: Since the general consensus had covered the free PHP analysis tools as not being great, and another commenter had mentioned commercial tools, I though I would throw it in for completeness.  I'm happy to delete it, though.
Answer: The Spike PHP Security Audit Tool is another static analysis tool to scan for security problems in PHP code.
Answer:
Acunetix
Nikto
Nessus
Wapiti
QualysGuard WAS
w3af

These will scan and audit your server/website and return insecurities. They are very useful.


How cricket analyst store information of first 7 order lowest score table also?

Question: Sports channel displayed First 7 order lowest score table of INDIA, showing lowest runs made on 7th fall of wicket. How did they manage to do it?
Answer: The simple answer is "in a database". Assuming you've done the hard work of getting it all into the database in an appropriate form, it will be as simple as (in psuedo SQL):
<code>SELECT * FROM wicket_falls WHERE wicket = 7 AND team = 'India' ORDER BY score
</code>
The other possibility is to use ESPN Cricinfo's "stats machine", but I'm rubbish at driving that so can't give you a like right now.


Can CPI and real GDP have high correlation?

Question: I have historical data where the CPI and GDP are correlated. Does this make sense? If not, how do I test for it?
Comment: @Dqingqong please could you [edit] in that extra information, into your question?
Comment: They could be correlated, but they don't have to be. What's the problem you're trying to solve here?
Comment: You should definitely plot your data because the correlation may be driven by large outliers or non-stationarities. It is not clear why absolute real GDP and CPI should be highly correlated unless you are working on a economy that is highly dependent on commodities.
Answer: There was a degree of economic stability between the UK's exit from the Exchange Rate Mechanism in 1992 and the World Financial Crisis in 2008: positive real GDP growth typically between 2% and 4% and low steady inflation typically between 1% and 3%.
The Governor of the Bank of England called this "The Great Moderation".
The effect is what you have observed: the level of real GDP and the level of the CPI both grew, apparently highly correlated with each other, as shown in the red line below based on quarterly data.
But this correlation was an artefact of each indicator growing itself over time and of auto-correlation, as well as not having a recession in that period or sudden spikes in prices; looking from 1991-2009 would have produced a less smooth chart.
If instead you look at the percentage changes over the previous 12 months, the apparent linearity collapses, as shown in the blue line below.

Comment: @denesp - I do not know what makes you think that.  It is the [ONS time series ABMI](https://www.ons.gov.uk/economy/grossdomesticproductgdp/timeseries/abmi) while nominal GDP ([YBHA](http://www.ons.gov.uk/economy/grossdomesticproductgdp/timeseries/ybha)) typically grew by 3%-7% a year over the same period
Comment: This seems to be nominal, not real GDP.
Comment: My mistake. The growth seems to large and sustained to be real. Having looked it up, I now see this was indeed the case. Thank you for providing the source though.
Answer: The CPI encompasses the price of consumed goods (some of them are domestically produced, other are imported). The GDP deflator takes into account only the goods produced domestically (some of them are consumed here, other are exported).
Thus there is some correlation between the GDP deflator and the CPI as you can see below

(my own plot, the series are from FRED database (GDPDEF and DPCERD3Q086SBEA), seasonnaly adjusted, growth rate between the same quarter from the previous year)
Having this in mind, recall that the real GDP is calculated as the nominal GDP divided by the GDP deflator. Thus the price of the domestic goods procuded and consumed in the country are in both CPI and real GDP. Here comes your correlation.


What is the point of level 20 features?

Question: What exactly is the point of the "capstone" features? Unless your group goes beyond level 20, won't your campaign be over, or virtually over? Most of the capstones are incredibly awesome, so it would stink to not get to use them.
Answer: First, your level doesn't determine when the campaign ends, the story does.  You could reach level 20 while in the final leg of the campaign, but before the end.  So you could use those awesome abilities in the final battle.  Heck, you could reach level 20 before the final arc of the campaign, and have a while to use those powers.
Second, many campaigns continue on past level 20.  In previous editions there were books published for just that purpose, and one can easily assume those will come for 5E if it is successful enough.  Even without them, one can continue to level following the standard progressions, and potentially house-ruling new, cool capstone powers for L21+.  I'd be willing to bet if you look you can probably already find some of those on the internet.
I also just learned that the 5E DMG (which I do not own) already has suggestions for continuing past level 20.  Instead of continuing to level, players get Epic Boons (a.k.a. super Feats) at certain XP increments.
Third, your question is self defeating.  If there was no power at level twenty, people would either ask why not, or complain that there was no point to level 20, and say that level 19 was the effective cap.  At which point the same thing can apply to level 19.  Repeat ad nauseam.
Comment: +1 for proving that all levels are pointless via inductive logic.
Answer: First of all, as has been mentioned, campaigns do sometimes see actual play occurring at 20th level, or even higher. So your question actually includes some assumptions that are not quite true.
However, I do some third-party work for D&D 3.5 and its spin-off Pathfinder, which, like 5e, have a cap at 20th, and in practice, are rarely played at such high levels (most campaigns actually stay at quite low levels). Nonetheless, "capstones" are still quite important to a class's design, even if they are rarely used.
So this is an answer to your question, accepting your premise that 20th-level class features will be rarely used, if ever. Again, note that this is not necessarily the case.
Capstones are still important because they reflect the ultimate power of that class. They represent the culmination of all their training and skills, and what they can now do. And as you say, they're awesome—and as a designer, that's the most important thing in a capstone to me. The capstone is supposed to inspire you, excite you. Get you to really love the class's potential.
They're also an opportunity to flex a little as a designer. Like you say, a campaign is probably nearly over by the time you get one, if you ever do. The capstone represents an opportunity for the gloves to come off and to write something really crazy. That's not to say that there are no rules, or that nothing is "too much" for a capstone, but you can "get away" with a lot of things that would elicit a negative reaction from readers if offered earlier.
Answer: The DMG has continuing increases in power for 20th level characters. The capstones are the reward for being single-classed through to "epic tier"...  but the Epic Boons are quite nice, too.
It's thus clear from the DMG that the intent is to allow continued play at 20th level. Note, no provision for higher levels, just additional feat-like boons at regular intervals of earned experience.
Note that while characters cannot exceed level 20, level 20 isn't the end of power growth, just the end of HD, HP, and Proficiency Bonus growth.
Answer: Capstone powers/abilities/whatever you want to refer to them as (generally just class features) are the penultimate potential of the class. Getting them says that you are a MASTER in that class. It's the reward for sticking to the class to the bitter end. The purpose is to use them in the final dungeon. You are now a legend. You are a kung fu master, a black belt in karate, a super genius archwizard, the archbishop of your church, or whatever. (Not strictly speaking those exact roles - some require you to be ordained or promoted in station, or whatever, but that illustrates the point).
These sorts of things are epic by definition, though the game has special rules for "epic play" - beyond 20th level. At that point you're effectively a minor deity in your own right.  At such a point, there's usually nothing left to do than literally save the world from the all-powerful Lich King, the Final Wyrm, the Destoryer of Worlds. You can now go toe-to-toe with the final boss, the whole point of most campaigns. Your challenge will take all of it out of you, but 20th-level powers allow you to succeed against 20th-level baddies, which is generally what the Big Bad will be (or higher! And he/she/it should be even more challenging with cunning plans, powerful spells, mighty attacks, an army of minions, a temple or dungeon of pain, etc. Might even have a god on their side!)
The Magical McGuffin - some kind of artifact that will save the day from the villain - will be used.
All the world holds its breath; the outcome of this final battle will decided the fate of the very world! It's Good and Evil's final battle, and these abilities facilitate combat on the tier reserved for only the masters.
Answer: Some campaigns can and do play at and go beyond level 20, so capstone features do get use for those games.
But another thing to keep in mind are magical items like the Deck Of Many Things that can boost your experience or level. So even if your campaign is over or virtually over at level 20, it's possible one or more of the players can get to 20 early through use of magical items, and that point can benefit from their capstone as a reward.
Comment: This does not provide an answer to the question. To critique or request clarification from an author, leave a comment below their post. - [From Review](/review/low-quality-posts/52762)
Comment: @Ruse The last sentence is directly tying the rest of the post to how it is answering the question.
Comment: Yeah, I'd agree that it answers the question, though it's phrased more like a comment than a standalone answer. Frozenstep, I'd suggest summarizing any relevant info from other answers so that your answer stands better on its own.

What is the point of level 20 features?


Why is this formula useful in Iron Man 3?

Question: I watched Iron Man 3 today, and wonder what this formula is about. Is it an important topic of physics? You know, like Transformers: Dark of the Moon, as I can recall, when an answer of some formula (problem) is got, an amazing weapon is invented. But I don't see any relationship in this movie. The picture is below:
Comment: Apart from *SystemDown*'s already given (and most probably correct) answer, the actual answer to the question *"I wonder what this formula is about. Is it an important topic of physics?"* is probably just that it's random math-scribble that's supposed to look complicated. You're just not supposed to make any sense of the particular symbols (since you also don't know the whole of the *Extremis* formula and thus the actual context of the formula).
Comment: I am just curious about what that formula stands for, and I find the wiki [page](http://en.wikipedia.org/wiki/Extremis). It is from a comic book. Thanks for your comment.
Answer: This formula was the problem that Dr. Hansen needed to solve to fix the flaws with the Extremis virus. As you saw in the movie, many people who are subjected to the virus reject it and die violently. Dr. Hansen's attempts to solve it always failed, but she knew Tony Stark was smart enough to do it. So the whole plot of the movie was her and Killian attempting to force Tony to solve it, and thus fix the flaws of the Extremis virus.
Comment: You mean bomb oneself uncontrollable?
Comment: @eccstartup - Yes. Many of those exposed to the virus (especially at the start) couldn't control it and detonated.
Comment: This is correct as seen in the scene where Happy touches the ficus plant and it then starts to burn and then explode that is Dr. Hansen's early experiments with Extremis. After Tony's one night stand with her he leaves a formula that allows her progress past that stage to being able to use it on humans.
Answer: This is the Baker-Campbell-Hausdorff formula. It demonstrates the difficulty in extending exponentials beyond strictly numbers to include things like vectors. Specifically in quantum physics it describes "quantum entanglement" which is (in general) still a largely unsolved problem.
As it appears here this equation seems to be written as to explain the interaction between two opposing electrons (alpha and beta) and the spin angular momentum (J) and wave function (Psi) of a system respectively.
Tony's basically saying that if you want to explain how two different forces will act on a system when combined then first describe to what degree those forces cancel each other out and then look at the effect of the force left over.


When did people realize that the eye was a lens?

Question: All in the title:
When did scientists realize that our eye functions like a lens/magnifying glass?
Comment: The eye is not and was not a lens. It CONTAINS a lens.
Comment: Yes, true, sorry to have reduced such a magnificent apparatus to only one of its parts :)
Comment: @AlexandreEremenko Yes, the eye contains a lens - However, even without the physical lens material of the eye, any smaller opening has the effect of sharpening an image (lensing) due to some parts of optics we often forget. Here is a fantastic video on this and it has a great example of a classroom activity of making a pinhole lens with your hand. [How To See Without Glasses](https://youtu.be/OydqR_7_DjI)
Answer: When Did Humans First Observe a Lens in an Eye?
People probably realized that the eye contained a lens (at least the eye of a fish) as soon as they began fishing for dinner.  So, sadly the discovery of the hard lump that is a fish lens was probably prehistoric.
Here is a picture of a fish lens from an Instructable on fish dissection.
http://www.instructables.com/id/Fish-Dissection/
Now, we have 3 things left to figure out:

When did humans figure out what this clear, "lentil shaped" (the word for lentil and the word for lens are the same in Greek and Latin) object in a fish eye was for?
When did they find out that the human eye also had one?
When are we sure they put all this together with a theory?

1. When Did Humans Know What The Fish Lens Was For?
We have a hard, clear lump that humans could have found in a fish's eye.  When did humans start to use similarly shaped items to see things better so that we have some idea that they knew what that lump in the fish eye was for?
This article (http://www.wikiwand.com/en/History_of_optics) notes the Nimrud-Layard Lens dated from 750 BCE as the first evidence we have.

But, if you follow their link to the site and read the full description, there is evidence that this "lens" was decorative.
Yet, the object has optical properties that have been measured such as its focal point

Harry Thurston Peck, in Harpers Dictionary of Classical Antiquities (1898) assures us (without a citation) that the ancient Assyrians:

...were acquainted with glass; that they employed the arch in building; that they used the lens as a magnifying instrument; and had, among other mechanical appliances, the lever and the roller.

Euclid describes the geometry of optics in his work, Optics in 300 BCE.  And, it is important for us to remember that Euclid was more of a textbook compiler of existing knowledge than someone who was creating and discovering the things he wrote about.  Much of his work has been traced back to Sumer.
But, his Optics could be better titled The Geometry of Perspective as they don't really relate to the refractive properties of a lens (although I haven't read them in depth).
In his book, QED: The Strange Theory of Light and Matter, Feynman points out that the evidence that prehistoric man understood refraction goes back to the first successful spearfishing.

Science Learning Hub
For evidence of use of an optical lens from at least 68 AD we have:

In the writings of Pliny the Elder, we have a description of the use
of what was either an emerald of another green gemstone that was
classed as a smaragdus.

And then, besides, when viewed from a distance, these stones appear all the larger to the sight, reflecting as they do, their green hues
  upon the circumambient air...In form they are mostly concave, so as
  to re-unite the rays of light and the powers of vision: and hence it
  is, that it is so universally agreed upon among mankind to respect
  these stones, and to forbid their surface...When the surface of the
  smaragdus is flat, it reflects the image of objects in the same
  manner as a mirror.

2. When did they find out that the human eye also had one?
We have apparently lost the original works where Aristotle published his vivisection and dissection notes from his work on the Island of Lesbos between leaving Plato's Academy (when he was passed over to head it after Plato's death in 348 BCE) and a couple of years later when he returned to Macedonia to act as Alexander the Great's tutor.
But, thankfully, the Arab scholars did not throw out the "Pagan" works of the Greeks.  And in Ibn al-Haytham's work (965–1039 AD), we have what is said to be a copy of one of Aristotle's diagrams of the eye.  It appears to show a lens.
I am not sure what animal this is from.  But, we know that Aristotle noted a difference between mammalian eyes and those of cuttlefish.  So, I would say it was almost certain that at this time is was known that the human eye contained a lens (even if no one admitted to human dissection).
I am also not certain that this is actually a copy of Aristotle's drawings.  This may have been reported this way by those who wish to demonstrate that Arab cultures contributed nothing to science.  So, this drawing may have dated from  about 348 BCE or about 1400 years later...  Reading the Arabic would help.
So, either this diagram predates Galen's 2nd Century AD work by a few centuries or it came a few centuries after...  Sorry!

Ibn al-Haytham (965–1039 AD), The original portrayal of the modern theory of vision
We certainly have established that knowledge by the time Leonardo makes his scandalous drawings of cadaver dissections.

3. When are we sure they put all this together with a theory?
The excellent answer above from CarlW about Galen is earlier than what I knew about from the Islamic Golden Age.  Namely that Ibn al-Haytham (965–1039 AD) seems to have pulled this all together in his work.  But, that isn't to say that the investigators in Europe in the Scientific Revolution didn't have to rediscover this on their own and came up with additional nuances and questions.  (One of Newton's problems with the particle nature of corpuscles and light passing through lenses would not be answered until Quantum Mechanics-- as Feynman points out.)
Final Note:
There are a lot of "but they couldn't have understood optics" writers that comment on the early or ancient use of the lens.  But, we humans have a tendency to believe that all who came before us were far more ignorant and unimaginative than our own enlightened generation.
The thinkers who wrote about optics in the Scientific Revolution, for example, were wealthy and far removed from the act of fishing for their dinner and preparing that fish.  As a child, I fished with my father for dinner many times.  And, while preparing it for dinner, he showed me how to extract the lens from a fish's eye.  So, earlier thinkers had a ready-made example of how the lense should look (lentil-shaped and transparent) for them to copy and experiment with.
Hope this helps!  Oh-- and don't forget-- the Greeks used Camera Obscura techniques to observe the eclipse.  That's how Aristarchus estimated the distance from the Earth to the Sun.
A huge help in tracking down sources for my answer was this web page.  After you search for a word in their database, there will be a place to the right of the page where you can limit the results by document where they are found-- so you can get closer to the time period you are interested in.
http://www.perseus.tufts.edu/hopper/
Comment: This does not appear to address the question, which was about the lens inside the eye
Comment: Wow, thanks a lot for this detailed and complete answer.
Answer: Probably the Swiss physician Felix Platter (1536 – 1614) that - according to Olivier Darrigol's A history of optics : From Greek antiquity to the nineteenth century, Oxford University Press (2012), page 23 - in his :

anatomic treatise of 1583 made the retina the sensor of the visual species, and the crystalline humor a magnifying glass (perspicillum). [...] Perspicillum was the Latin name then given to a growing popular device: the eyeglass.

See  Felix Platter, De partium corporis humani structura eius et usu Libri III (Basel, 1603 ed), page 186.
Answer: Here's a very early bit of research.  While it identifies the lens as critical to vision, it doesn't seem to recognize  the lens as a focussing device  From some classroom notes

In the second century A. D., Galen had at least two different theories
  of the eye to choose from.  He chose the extramission theory because
  it corresponded well with his image of sight as a function of an
  optical pneuma, flowing forth from the brain to the eyes through
  hollow optic nerves.  Galen defined many of the fundamental features
  of the anatomy and physiology of the eye until the seventeenth
  century.  Benefiting from the work of the anatomists who dissected in
  Alexandria, such as Rufus of Ephesus, he described the retina, cornea,
  iris, uvea, tear ducts, and eyelids, as well as two fluids he called
  the vitreous and aqueous humors.  He noted some of the peculiar
  features of sight such as binocular vision.  Galen paid particular
  attention to the crystalline lens, which he described as a round lens
  in the middle of the eye.  He concluded:  "the crystalline lens is the
  principal instrument of vision, a fact clearly proved by what
  physicians call cataracts, which lie between the crystalline humor and
  the cornea and interfere with vision until they are couched.

This same page goes on to credit Platter as recognizing the lens as an imager (and more or less putting to be the concept of the optic nerve as an emitter).
Comment: To check on original sources is not an easy task for non-specialists: a [Latin translation](https://books.google.it/books?id=Efw1AQAAMAAJ&printsec=frontcover&dq=Galen+De+Usu+Partium+Corporis+Humani&hl=it&sa=X&ved=0ahUKEwjyw5P51a_aAhXLliwKHUUsC08QuwUINTAB#v=onepage&q=Galen%20De%20Usu%20Partium%20Corporis%20Humani&f=false) of 1528 (page 287) has *crystalloeides*, and I doubt that it conveys the modern concept of *lens*.
Comment: Maybe we have to chek on the Greek original... "crystalline lens" is the translation of what ? and the same for "he described as a round lens". We have to be clear about words: *leans* is any *transparent medium* or it is "something more" ?
Answer: Sushruta was a surgeon who developed cataract surgery and must have seen the human lens.
https://www.aao.org/senior-ophthalmologists/scope/article/sushrutaSushruta in 600 B.C. introduced extraocular expulsion of lens material.
Grzybowski A1, Ascaso FJ.
Author information
Abstract
It is generally accepted that Jacques Daviel introduced in the 18th century the extracapsular technique of extraction of the lens while the couching method of cataract operation had already been practiced since ancient times. Present study analyses the first known cataract surgery description in three translations into English from the original Sanskrit Sushruta textbook and all the available literature on the subject. We found evidences that some sort of extraocular expulsion of lens material through a limbal puncture (paracentesis) was described by the Indian surgeon. Nevertheless, this incision cannot be considered as a classic extracapsular procedure because it was not large enough to allow the extraction of the entire lens.
© 2013 The Authors. Acta Ophthalmologica © 2012 Acta Ophthalmologica Scandinavica Foundation.
https://www.ncbi.nlm.nih.gov/pubmed/23464869


Is it halal to use shampoo containing hydrolyzed collagen?

Question: I found out that collagen is haram to consume especially because it is most likely to be from a pig. But what about collagen in shampoo?
Answer: Pig-derived collagen would be impure (najis).  Consider consulting the manufacturer, as your shampoo may not be derived from pigs.
In the following fatwa, the hydrolyzation process was considered an insufficient transformation to change this status in the context of creams and lotions:

Hydrolyzed collagen is produced from collagen found in the bones, skin, and connective tissue of animals such as cattle, fish, horses, pigs, and rabbits. The process of hydrolysis involves breaking down the molecular bonds between individual collagen strands using heat and either acid or alkali solutions. (www.naturalpigments.com)
Hydrolyzed collagen will have the same ruling as gelatine, therefore, if the gelatine is derived from haraam sources namely pigs or any other animal upon which Allah's name has not been mentioned, it is not permissible to use it.
Mohammed Tosir Miah, Darul Ifta Birmingham, 2012 fatwa

Assuming the shampoo is impure, the question now becomes: is it halal to use impure shampoo?
Islam Q&A says no:

The materials which are used to manufacture... shampoos... ...[if] it comes from animals whose meat and fat are forbidden to eat, such as pigs... it is haraam, with no doubt.

but with the caveat:

...the basic principle with regard to such things is that they are taahir (pure) and it is permissible to use them, until it is proven from a trustworthy source that they are mixed with pork fat or some similar impure substance which it is haraam to use. In that case it is haraam to use them. But if the news is no more than a rumour and is not proven, then it is not obligatory to avoid using it.

Likewise, a IslamWeb fatwa discussing shampoo containing alcohol:

...it is not permissible to benefit from an impurity


How does Ethereum differentiate between 0x0 and null during contract creation?

Question: According to the EVM documentation, all values are initialized. This means to will contain the 0 address, as null is not a recognized state. The 0 address links to an external account (which we all know contains a trove of ether and tokens). So, how does ethereum distinguish a contract creation request from a value transfer request originating from sender to address 0x0..0?
Does the payload content of the data property then determine whether this is a contract creation request, e.g., parser sees to == 0x0 && data == 0x0 and results in value transfer to account 0x0..0.
Answer: Thanks to @Ismael who clarified how the RLP encoding handles data during contract initialization. It seems the encoding protocol can distinguish between empty byte array and address. The rules of the EVM are then different and irrelevant here.
Implementations can choose to handle payloads differently. For example, javascript web3 address entries of 0 & 0x0 no longer send value to the genesis address through web3, but are unfortunately interchangeable with undefined due to the behavior of JS. This change was made to web3 fairly recently... https://github.com/ethereum/web3.js/blob/59aae306c1c31ef6a65b9196e7f03af74c69e059/lib/web3/formatters.js#L274
This answers my own question, but thought it would be useful to post, since discussions of these finer points seem to be lacking in posts re: accidental payments to the genesis block address.


Fermentation Times in Extract vs. AG Brewing

Question: I've noticed that for certain recipe kits that come in both all grain or extract forms, that the directions for the length of fermentation (both primary and secondary) are generally longer for the extract kits.  Why is this exactly?
Comment: I do realise that the directions which come with kits are merely suggestions and a fermentation is deemed complete by measuring of the final gravity...my posed question is simply to settle a curiosity!
Answer: There is no particular reason I am aware of that normal fermentations for extract vs. all-grain brews should be different. Perhaps some examples that you've noticed might help?
Fermentation time is mostly a function of yeast health, wort oxygenation levels, yeast pitch rate, the gravity of the beer, and temperature. While extract might generally have less essential nutrients for yeast (I'm not sure, honestly, but I could believe that to be true), the other factors make more of a difference. Notice that almost all of those are nothing to do with the source of of the wort's sugars.
(Also, I wish the major retailers would stop recommending "secondary" fermentation on their instruction sheets. It is almost never needed.)


How to know at which price an item has been sold in auction house?

Question: I am exploring a bit the auction house in order to understand how the prices are going, but I can see only the price of items still available in auction. Does exist a way to see the price of items marked as already Sold?
Answer: I doubt there is a way to see the already sold items,
But you can ensure selling without knowing what the items have been sold for.
The best way to figure out a price is if there already are some. If it's something there already are prices on, trying going a bit under that.
Eg. you want tot sell a Stone of Jordan.
There are already 5 for sale, for around 5000g (this is a fictional price).
Set yours to sell for 4999g.
This is easier if there are a lot of the same item for sale (which can be hard for items with random properties).
Also having a buyout price can help a sale, if the others don't have a buyout price.
I hope this helps.
Answer: There is a way to get an approximate idea of the buyout prices of already sold items, but it is a bit tedious.
1) Look at the item which you are interested in. Set search criteria which would match the item you are interested in.
E.g. If you have a +191 strength, +44 resist all, +101 vitality, +50 dexterity ring
Then set the search criteria to 191 minimum strength, 44 minimum all resistances, and 101 minimum vitality.
The purpose of this is to reduce the amount of items that are listed.
2) Ensure that you see the item you are investigating in the search listing. Enter a maximum buyout criteria.
E.g. we can enter 10,000,000 gold. If the item you are investigating is still showing up, the buyout price was lower. If we lower the max buyout criteria to 1,000,000 gold, and the investigated item disappears, we know that the buyout price was larger than one million. If we want a more a precise value, we can increase the buyout criteria until the item shows up again.
Notice though, that this only gives information about the buyout price of the item in question. As far as I know, this technique would result in the conclusion that an item was worth 10,000,000 gold even if the item was sold for only 1,500,000 gold through bids (but had a buyout price of 10,000,000)


startup to desktop and then enter password

Question: Is there a way where we can startup to desktop then its going to ask for a password (like how you enter passwords for user accounts on windows) instead of the raspberry pi starting up with password then bring us to the command line? just so that the user doesn't have to enter 'startx' to get to the desktop gui.
Comment: if you have a working solution, you may answer your own question, that way your knowledge will be available for other people.
Comment: + this this question will be answered instead of remaining unanswered.
Comment: ppumkin - yeap doing that now, when i tried to answer my own question, said i had to wait for 8 hours. anyway, i'm answering it now :)
Answer: If you set the system to boot to the desktop but then edit the file /etc/lightdm/lightdm.conf and look for the line that reads:
<code>autologin-user=pi
</code>
and you change this to read
<code>#autologin-user=pi
</code>
Found it on http://www.raspberrypi.org/forums/viewtopic.php?f=66&t=69448