Implications Of Self Replicating Machine
April 27, 2010 8 Comments
Any sentient extraterrestrial civilization desiring to explore the Galaxy beyond 100 light-years from its home star should find it more efficient and economical to use self-replicating star probes because of the benefits of exponentiation. This will secure the largest quantity of data about extrasolar systems by the end of an exploration program of some fixed duration. The entire Galaxy can be explored in times on the order of 106 years assuming interstellar cruising speeds on the order of O.1c, now considered feasible using foreseeable human technology . Many who have written on the subject of theoretical galactic demographics have suggested that most extraterrestrial races probably will be found 100 to 1000 light-years from Earth and beyond. Hence it may be concluded that the most likely interstellar messenger probe we may expect to receive will be of the reproducing variety.
One of the tremendous advantages of interstellar probes over interstellar beacons in the Search for Extraterrestrial Intelligence (SETI) is that probes may serve as cosmic “safety deposit boxes” for the cultural treasures of a long-perished civilization. The gold-anodized Voyager records are a primitive attempt to achieve just this sort of cultural immortality . Starfaring self-replicating machines should be especially capable of maintaining themselves against the disordering effects of long periods of time, hence SRS will be preferentially selected for survival over nonreproducing systems. This fact, together with the aforementioned preference for using SRS for very long-term, large-distance galactic exploration implies that any alien machine we might find in our own solar system (as part of a dedicated SETI effort) still in adequate working order will most probably be a replicating system.
A number of fundamental but far-reaching ethical issues are raised by the possible existence of replicating machines in the Galaxy. For instance, is it morally right, or equitable, for a self-reproducing machine to enter a foreign solar system and convert part of that system’s mass and energy to its own purposes? Does an intelligent race legally “own” its home sun, planets, asteroidal materials, moons, solar wind, and comets? Does it make a difference if the planets are inhabited by intelligent beings, and if so, is there some lower threshold of intellect below which a system may ethically be “invaded” or expropriated? If the sentient inhabitants lack advanced technology, or if they have it, should this make any difference in our ethical judgment of the situation?
Oliver has pointed out that the number of intelligent races that have existed in the pant may be significantly greater than those presently in existence. Specifically, at this time there may exist perhaps only 10% of the alien civilizations that have ever lived in the Galaxy – the remaining 90% having become extinct. If this is true, then 9 of every 10 replicating machines we might find in the Solar System could be emissaries from long-dead cultures .
If we do in fact find such machines and are able to interrogate them successfully, we may become privy to the doings of incredibly old alien societies long since perished. These societies may lead to many others, so we may be treated, not just to a marvelous description of the entire biology and history of a single intelligent race, but also to an encyclopedic travelogue describing thousands or millions of other extraterrestrial civilizations known to the creators of the probe we are examining. Probes will likely contain at least an edited version of the sending race’s proverbial “Encyclopedia Galactica,” because this information is essential if the probe is to make the most informed and intelligent autonomous decisions during its explorations.
Further, if the probe we find has been waiting near our Sun for long enough, it may have observed such Solar System phenomena as the capture of Phobos, the upthrusting of the Rocky Mountains or the breakup of Pangaea, the formation of the Saturnian rings, the possible ejection of Pluto from Neptunian orbit, the possible destruction of a planet in what is now the Asteroid Belt. the origin of the Moon, or even the formation of our own planetary system. Perhaps it could provide actual visual images of Earth during the Jurassic or Carboniferous eras. or data on the genomes of long extinct reptiles (e.g., dinosaurs) or mammals, possibly based on actual samples taken at the time. There are countless uses we could make of an “intelligent eye” that has been watching our planet for thousands or millions of years, meticulously recording everything it sees.
SRS probes can be sent to other star systems to reproduce their own kind and spread. Each machine thus created may be immortal (limitlessly self-repairing) or mortal. If mortal, then the machines may be further used as follows. As a replicating system degrades below the point where it is capable of reproducing itself, it can sink to a more simple processing mode. In this mode (useful perhaps as a prelude to human colonization) the system merely processes materials, maybe also parts and sub-assemblies of machines, as best it can and stockpiles them for the day when human beings or new machines will arrive to take charge and make use of the processed matter which will then be available. As the original machine system falls below even this level of automation competence, its function might then be redirected to serve merely as a link in an expanding interstellar repeater network useful for navigation or communications. Thus, at every point in its lifespan, the SRS probe can serve its creators in some profitable capacity. A machine which degrades to below the ability to self-reproduce need not simply “die.”
The SRS is so powerful a tool that it could have implications on a cosmological scale. With the SRS humanity could set in motion a chain reaction of organization sweeping across the Universe at near the speed of light. This organized part of the Universe could itself be viewed as a higher level “organism.” Instead of merely following the laws of mechanics and thermodynamics, something unique in our knowledge would occur. The degree of cosmic organization would increase. Life could become commonplace, whereas now it seems quite rare. New rules, the rules of life, would spread far and wide.


"We followed the gulch down from the summit of the mountain into the basin… it was a beautiful sight to see the large pieces of quartz spangled over with gold," Richard Harris said on October 3, 1880. On that fateful day, Joe Juneau and Richard Harris, along with their Tlingit Indian guide, found gold in Silver Bow Basin in a stream they called Gold Creek. This event was the start of a nationwide gold rush to this largely untapped section of the world. Over the years, many people came to the wilds of Alaska searching for this precious metal. Having been there myself, I can tell you there’s ghosts in those hills and towns, too.
Last week, I traveled up the Alaskan coast and stopped at the towns of Ketchikan, Juneau, Sitka, Seward, and Anchorage. The history of these Alaskan towns is colorful to say the least — the gold miners were not the first residents of the area, of course. That distinction goes to the Tlingit Indians, who lived in what is now Southeastern Alaska for several thousand years. The Native American influence can be seen all over these towns, from totem poles and other native woodcarvings in the parks, to Tlingit artwork on the sides of buildings.
During the gold rush of the late 1800s and early 1900s, these Alaskan towns got their start as simple tent villages where miners slept when they weren’t digging or panning for gold. Eventually, buildings were erected, saloons opened, hotels and general stores began to take shape, and these campsites turned into towns.
I came to Alaska to see nature in all of its power and glory, but I also came looking for ghosts. For help on my quest, I spoke with Ron Wendt, author of Haunted Alaska — a collection of ghost stories from America’s last frontier. With Wendt’s help, I found a very "lively" haunting in the state capital of Juneau — a city of approximately 31,000 people. No roads or rails run into Juneau; the only way in is by boat or plane.
Juneau formed as a by-product of the gold rush and grew quickly. The town was originally called "Harrisburgh," but as the locals tell you, Richard Harris was not a very popular character. No one knows for sure who Joe Juneau lobbied to get the town’s name changed in his own honor, but one story says he bought a round of drinks for a large group of town residents and that was enough for them to change the name. In the heart of downtown Juneau, on a quaint street called South Franklin, sits the Alaskan Hotel.
The Alaskan Hotel was built in 1913 by the McCloskey brothers and Jules B. Caro, and it now sits on the National Registry of Historic Places. It is Juneau’s oldest continuously operating hotel. Originally a hotel and bordello, the establishment was set up for miners who were in town for work.
Back during the gold rush when the men significantly outnumbered the women, houses of prostitution were a popular place to be when the men weren’t working. According to Wendt’s research, the ghost that haunts the hotel is that of a woman who was driven to become a prostitute when her husband had gone into the hills to mine for three weeks and didn’t return. She ran out of money and thought that maybe her husband wasn’t coming back at all, so she became a lady of the night. Three weeks later, her husband did return and was so angry when he found out what she was doing that he killed her in the hotel.
I found more than one legend about how the haunting started after speaking with several people who worked at the hotel, some patrons at the bar, and even a former manager. I can tell you that though not everyone agrees on which part of the hotel has the most activity, or how the haunting got started, they do all agree it is haunted. I didn’t speak with a single local who didn’t know of the Alaskan Hotel’s ghost stories.
Jake Good, who was working at the front desk of the hotel when I visited, said, "People have told me they’ve seen things before, like seeing people in the hallways that look like people in paintings around here. I’ve never experienced any of that kind of stuff, but I’ve heard about it. The only reason that I personally believe that it’s haunted around here is because parts of the hotel just don’t feel right. Some parts of the hotel I just don’t feel safe at — I’m constantly turning around."
Good went on to tell me about room 219 in the hotel. He said, "Whenever I walk up into room 219, I get goose bumps. It’s cold in there all of the time for some reason. I personally think there are probably a couple of ghosts around here. I think the one in 219 is the only one that is frustrated or unhappy or tormented, I don’t know."
Good has only been working at the Alaskan Hotel for the past few months, and he told me how guests continually ask to be moved out of room 219. The patrons don’t usually give much of a reason, and Good says he doesn’t ask too many questions — he simply tries to accommodate them.
On a tip from one of the Alaskan Hotel bar patrons, I went across the street and found Scott Fry playing guitar in an acoustic duo — I walked in during the chorus of the old folk/blues tune "Stagger Lee." Fry was the manager of the Alaskan Hotel for 12 years, and I had a chance to speak with him during his break. Fry said, "Her name is Alice if I remember correctly, and she supposedly was a lady of the night. She got killed, and I was told originally it was somewhere in the back of the building. She lost her life to a jealous lover."
Fry also spoke of specific rooms with ghostly activity. He said, "Room 218. I used to get people saying, ‘She’s in my room.’ I’ve had people tell me that she was touching them, or they could see her sitting on the bed. A friend of mine told me if you walk up the top of the stairs, you could see her in the mirror by [room] 308. I’ve also had people tell me she was in the bar coming down the stairs. The bar has a lot of mirrors in it, and it’s easy to see things out of the corner of your eye, especially if you’re tired."
Fry said he has heard of activity in almost all of the rooms on the south side of the hotel. He himself never had any supernatural experiences in the Alaskan Hotel, but he has certainly heard many first-hand accounts from people who did.
Ron Wendt relayed a story he had heard from Elva Bontrager, who stayed in the Alaskan Hotel several years ago. Wendt said, "It wasn’t long after that she started working in Juneau that she started going to the Alaskan Hotel. She went into the bathroom there — it was an old-style bathroom — and then she came back out. The next time she went in, it was brand-new and she says, ‘What happened to the old bathroom?’ Everything had changed. It’s a pretty tremendous thing when the whole room changes while you’re there. She said others had also experienced that."
The people who live on the state’s Southeastern coast, in towns where everyone knows everyone else, have some intriguing stories and folklore to share. I may not have found any precious metals in the streams and hills of Alaska, but I found gold in the ghost stories of the great people I had the chance to speak with.


Learning to drive is an important life skill that provides individuals with independence, convenience, and mobility. However, the process of learning to drive can be daunting for many, especially those who are unfamiliar with the process. One common question that many individuals have is how many lessons does it take to learn to drive?
The answer to this question can vary depending on a variety of factors such as individual aptitude, the driving instructor, the type of vehicle being driven, and the number of hours spent practising. However, research suggests that on average, it takes around 45 hours of driving lessons for an individual to reach the driving test standard.
It is important to note that this figure is simply an average and can vary significantly depending on individual circumstances. Some individuals may require fewer lessons if they have a natural aptitude for driving or have previous experience behind the wheel, while others may require more lessons if they struggle to grasp the basics of driving.
The type of vehicle being driven can also have an impact on the number of lessons required. For example, learning to drive a manual transmission vehicle can take longer as it requires the individual to master the coordination between the clutch, accelerator, and gears. On the other hand, an automatic vehicle may be easier to learn as the individual only needs to focus on accelerating, braking, and steering.
In addition to the number of lessons required, it is also important to consider the quality of the driving lessons. Choosing a reputable driving instructor who provides structured and effective lessons can significantly reduce the number of lessons required. A good instructor will not only teach the individual how to operate the vehicle but also provide them with the knowledge and skills necessary to become a safe and responsible driver.
Furthermore, it is recommended that individuals supplement their driving lessons with additional practice outside of their lessons. This can include practising with a family member or friend who has a full driving licence or practising in a quiet area such as an empty car park. This additional practice can help the individual build confidence and reinforce the skills learned during their driving lessons.
In conclusion, learning to drive is a highly individual process that can vary depending on a variety of factors. While research suggests that on average, it takes around 45 hours of driving lessons to reach the driving test standard, this figure can vary significantly depending on individual circumstances. Choosing a reputable driving instructor, practising outside of lessons, and investing time and effort into the learning process can all help individuals become safe and competent drivers.


As strange as it may seem, we’re giving you a summary of the history of the miter saws. You might think that it’s not so interesting, but you really would be surprised.
For instance, did you know that the company didn’t actually patent the idea, which would have protected it from the competition for many years?
Bet you didn’t.
However, we must start from the beginning before we get to that part of the story. Believe it or not, there are a lot of people who have benefited from such a labor-saving invention.
The Original Miter Box and Saw, considered as the first miter saws for most carpenters of the time.
The first innovation of miter saws usually had a wooden/plastic three-sided box, as well as 45 and 90-degree slits that will help guide the back saw or hand to make miter cuts. Essentially, the miter saw combines the options of a miter box with a carpenter’s backsaw.
Raymond DeWalt invented the radial arm saw in 1922. Within a few years, his invention became known as the gold standard for cutting long pieces of stock to the proper length.
As a matter of fact, the radial arm saw became the go-to tool for this purpose until the 1960s, when the power miter saw was invented. Learn More
Ed Niehaus invented the power miter saw in 1964 as a project for his boss, Rockwell. Ed Niehaus is one of the most significant names, and there is absolutely no way that you can mention the history of the power miter saw without singling him out. Learn More
When was invented the sliding compound miter saw?
At the end of the 1980s, the first sliding compound miter saw was presented, this new machine uses the principal elements of the compound mitre saw with sliding rails that allowed the cutting head to move for a longer cut. Since then it has been the primary main cross-cut saw for woodworkers, totally substituting the famous chop saw. Learn More
Now Talking About Niehaus invention We all Ask the Same Question
How did this happen?
Well, back in 1964, Niehaus was an employee for Rockwell Manufacturing Co., one of the world’s top manufacturing firms at the time. Niehaus was an engineer with the firm, and he was put in charge of project designers. The company gave Niehaus a challenge to develop a completely new category of tools. Niehaus was a worker at the company’s facility in Pittsburgh, and he was selected to work on it.
Speaking about the project, Niehaus said that he was tasked with building a project which would have been similar in operation to a handsaw miter box, but which will be powered by a motor.
Essentially, the company claimed that they were looking for a tool that could effectively crosscut and miter a 3×4 object. It was also required to be able to miter a piece of standard crown molding efficiently.
Niehaus said that he saw an idea sketch, in which he was shown the movement of the saw. He believed that the design might not be easily stabilized, so he developed a pivoting arm to mount the saw. This improved cutting efficiency a great deal.
So, Niehaus threw in a spring feature and put the arm of the saw to the arc’s top. He also went further by developing a compartment that improved the stability of the spring and maintained its functions efficiently. Then, he built a clear plastic blade guard which made way for the badge when it was time for the latter to work.
The entire table had a wooden material, which increased the speed and effectiveness with which the badge was able to slide through the object. Also, thanks to the seamless design of the table, it was easy for a user to replace it whenever it got too damaged or chewed up due to cutting a lot of angles.
Niehaus also added some awesome features. For instance, there was a blade brake and a dust port. In case you are confused concerning the blade brake, take a look at a miter saw’s handle top. The node is the safety switch to see there. It might have a modernized look or name, but it was initially developed by Niehaus
The entire project by Niehaus and his team took about three years of careful planning and product design. When it was all said and done, Rockwell launched the model 34-010 power miter saw to their customers.
The product was a smashing success at the time. It had a blade that measured 9 inches, so it could pretty much be used for a wide array of cutting exercises. Within a short amount of time, the tool began to outsell pretty much every other thing that Rockwell ever produced.
It was the goose that laid the golden eggs for Rockwell.
Niehaus said, “We couldn’t believe the sales numbers. They increased every year. That’s when we knew we were really onto something.”
The only problem here was that Rockwell didn’t get a patent right on the product for reasons unknown to this day. If they had, then they could have protected themselves from any other company which wanted to ride off the success of their product and design something even more revolutionary. Sadly, they didn’t.
As soon as the company’s counterparts realized that the miter saw was getting even more popular than other tools, they inquired about whether it had a patent. Upon finding out that it didn’t, they set to work and began developing their own versions with minor tweaks and changes to some of its fundamental features.
This wave of innovation is still being witnessed to this day, and now, you can see a lot of miters saw designs in the market.
As things stand, the common types of miter saws include:
The power/standard miter saw:
This is a powered version of the miter saw. It helps to seamlessly make straight crosscuts on a piece of work, and it provides the opportunity to do so at various angle ranges. A lot of the time, these saws are used to make 45-degree straight cuts in a framing project.
Compound miter saw:
This form of miter saw is a single compound miter saw, essentially implicating that the head can only rotate when it is angled to aside. If you are looking to get inclined cuts in the other direction, then you will have to flip the board.
Dual compound miter saw:
This type of miter saw makes it possible for the head to rotate, especially when it is angled on both the right and left-hand sides. Most people who use these do decorative trim projects.
The sliding compound miter saw:
These miter saws can move the head of the saw backward and forward on a sliding rail. They work in a similar fashion to the radial arm saws. Thanks to this saw head movement, the size capacity of the cutting board will be significantly increased.
The LED/laser miter saws:
These are most likely the most recent innovation in miter saw designs. They come with laser guides, which help with making more accurate cuts. The laser is made of a disc-shaped washer which is attached to the saw blade. It shows a line for which the saw will cut.
Many saws also have LED features, which help with better illumination.


Country operational research priorities pending.
- What factors are associated with the availability, accessibility, and acceptability of MDA?
- What is the impact of an adapted and tailored intervention package on effective coverage?
Identify the sampling strategy for tracking positive cases after TAS 2 and TAS 3 that optimizes the chances of correctly identifying evidence of active transmission, while saving program resources
To compare the performance of the diagnostic tools currently available for O. volvulus in terms of their relative sensitivity, species-specificity and practical use by countries. Comparison of the utility of these tools for mapping and surveillance in settings with different levels of endemicity for onchocerciasis (Oncho), lymphatic filariasis (LF) and/or loiasis.
To study the feasibility of LF and Oncho (Filariases) integrated transmission assessment survey (iTAS) according to both LF and Onchocerciasis WHO elimination guidelines
To determine the feasibility of the use of entomological traps by community members for onchocerciasis and lymphatic filariasis entomological assessments.
Compare coverage evaluation methods to identify a method that is statistically rigorous and feasible for programs. This study will focus on assessing MDA coverage for lymphatic filariasis by comparing the cost, time and feasibility of 3 different methods: the EPI approach (n=1768), LQAS design (n=95) and probability sampling alternatives (n=1768).
Primary Findings and Lessons Learned
Coverage surveys are an important tool for programs to evaluate their reporting systems and to determine whether effective MDA coverage has been achieved. However, for various reasons coverage surveys are seldom implemented. Some key challenges are: perceived technical difficulty, lack of resources, and lack of standardized guidance on how to conduct coverage surveys. This protocol seeks to address the 1st and 3rd points by comparing the feasibility of three different coverage survey methods (EPI approach, LQAS, and segmentation). This study was completed in 3 districts in Burkina Faso. All 3 districts found that their survey coverage was above the WHO target threshold (65% for LF). Furthermore, in all 3 cases the survey coverage validated (or nearly validated) the reported coverage. Taken together this suggests that the Burkina Faso program is working well. The feasibility results found all 3 methods to be very similar with regards to time, cost and perceived difficulty. Because only the segmentation approach results in a probability sample, this method was recommended by the M&E Working Group and ultimately approved by the STAG. Since the approval, significant work has been underway to create guidelines for conducting coverage surveys for preventive chemotherapy. An excel tool was created to improve the usability of the tool and online learning modules are currently in the works.


In the context of discussing animals that are produced from the mating of different species (see yesterday’s daf), the Gemara introduces a koy – an animal that has the features of both a wild animal and a domesticated one. At first, the Gemara assumes that the koy is the result of a union between a deer and a goat, but on today’s daf Rav Yehuda suggests that it is a beriah bifnei atzmah – it is a unique creation – about which the Sages could not conclude if it is a wild animal or a domestic animal. The Gemara points out that this is a disagreement that hearkens back to the time of the Tannaim, quoting a baraita where Rabbi Yosei echoes Rav Yehuda’s position that the koy is a unique species, while Rabban Shimon ben Gamliel testifies that it is a domesticated animal – the family Dushai would raise flocks of them.
Identifying the koy is a difficult task. Even though it is mentioned many times in the Mishna and Talmudic literature, that is not because it is a common animal, rather because its status between a wild and domesticated animal allows it to serve as a test case for many halakhot. The disagreement as to its identification began in the time of the Mishna, when some of the Sages argued that it is the offspring of a deer or similar animal with a goat. Others claim that it is a unique type of animal – an Ayal ha-bar ( a wild ram).
The Ayal ha-bar can be identified with the ovis musimon, which, according to many, is the forerunner of domesticated cattle. It is distinguished by its short hair and grey color, and it lives in mountainous regions, where it is a nimble climber – today mainly in uninhabited areas in Europe. It is likely that the clear similarities between a koy and a sheep, together with its being a wild animal, led to the Sages’ confusion about its classification.
Its name, “koy” and even the pronunciation of the name, are themselves the subject of disagreement.


2 Answers | Add Yours
There is an increasing distrust in traditional education--cost, efficiency, effectiveness, bullying, etc. Home schooling--by committed, conscientious adults--not only avoids these shortcomings but also adds many advantages, such as indivualized attention, flexible concentrations, convenience of travel, etc. Years of experiment and trial have refined home-schooling practices, such as group activities for several families together. Instead of teaching toward a government standard, parents can build learning modules with projects that teach multiple skills at the same time, rather than breaking things into artificially time units. Finally, art, music, etc. can be incorporated into the day without sacrificing other subjects.
Home schooling has the ability to curtail learning methods and curricula to the student. It can give choices and is more constructivist in nature. Home schooling may also give high achievers an advantage in that they will be actively involved in their learning at all times. They will also be able to work at their own speed.
We’ve answered 317,706 questions. We can answer yours, too.Ask a question


He discusses behaviors that he has observed in marriages that are successful and those that are detrimental to marriage based on his research conducted at his love lab in Seattle, Washington. He has outlined seven principles that will reinforce the positive aspects of a relationship and help marriages endure during the rough moments.
1. Enhance Your Love Maps.
Gottman defines a love map as the place in your brain where you store information pertaining to your partner. This is crucial in really knowing your partner, their dreams, hopes, interests, and maintaining their interest throughout the relationship.
2. Nurture Your Fondness and Admiration.
This means laying down a positive view about your spouse, respecting and appreciating their differences.
3. Turn Toward Each Other Instead of Away.
Acknowledging your partner's small moments in life and orienting yourself towards them will maintain that
necessary connection that is vital for the relationship.
4. Let Your Partner Influence You.
It is important to maintain your own identity in a relationship, but it is equally important to yield to your partner and give in. If both partners allow one another this influence, then they will learn to respect one another on a deeper level.
5. Solve Your Solveable Problems.
It is important to compromise on issues that can be resolved, which Gottman believes can be accomplished by these five steps: soften your startup, learn to make and receive repair attempts, soothe yourself and each other, compromise, and be tolerant of each other’s faults.
6. Overcome Gridlock.
Major issues that cannot be resolved because both partners’ views are so fundamentally different involves understanding of the other person and deep communication. The goal is to at least get to a position that allows the other person to empathize with the partner's view, even if a compromise cannot be reached.
7. Create Shared Meaning.
Create a shared value system that continually connects the partners through rituals/traditions, shared roles and symbols.


Perfectly sharp images are what many photographers want and strive for. A blurry shot will look mediocre compared to one that is sharp, no matter how spectacular the subject matter is. Fret not. It's easy to get up and start taking pictures; it doesn't take much work to get those clear, sharp photographs you've been hoping for, either. It takes just a little familiarity with some technical trivia.
1Avoid camera shake. Watch your shutter speed. As a general rule, you should not allow this to fall to a speed slower than the reciprocal of your 35mm equivalent focal length. However, if you're using digital (or are willing to use your film up a bit quicker), you can try taking several shots in succession and hopefully one will have a satisfying level of sharpness.
- Turn on vibration reduction (also called "image stabilization", depending on the manufacturer), if you have it. When VR/IS is on, the lens element(s) or image sensor move so that the image stays in place when projected onto the sensor. As a result, camera motion is less likely to affect the sharpness of your photographs. Turn it on whenever the lighting conditions makes getting a sharp picture difficult. Keep it off when you're shooting on a tripod; it isn't needed and actually makes your photographs less sharp.
- Use a shorter lens (or zoom out) and get closer. Remember that, according to the reciprocal rule of photography, reducing your focal length will give you less camera shake at any given shutter speed. Additionally, when you're using a variable-aperture zoom, you can often use a larger aperture with shorter focal lengths. Furthermore, getting closer might force you to be more creative when framing the picture.
2Set your aperture wisely. Most lenses are sharpest two or three stops wider than the minimum aperture (usually around f/8 or f/11).
 Using smaller apertures will force longer shutter speeds, too, which will increase the risk of camera shake causing your photos to be unsharp.
(With that said, if it's a choice between necessary depth of field and diffraction, then you might choose to err on the side of diffraction over defocus. Diffraction is a relatively simple phenomenon compared to defocus, and it might be easier to correct later on in software. Defocus is not; it'll differ on the same lens depending on aperture and subject distance, and varies again from lens to lens.) If you need to stop down because you want a longer exposure, purchase an ND filter.
3Watch out for focus misses. This can be caused by either human error (you) or camera error.
- Haoda Screen.
- Make sure your autofocus is not missing. Some combinations of lenses and cameras do this, for reasons probably best known to the people who make them. Try it out; if you get consistent focus misses on a known good lens then you should return your camera for servicing.
- Use your AF lock. If your subject doesn't fall under an autofocus point, select the AF point nearest to your subject, move the point over the subject, lock autofocus, and reframe. Keep in mind, however, that locking the autofocus also locks the auto-exposure. If so, you may have to use exposure compensation.
- Get your rangefinder calibrated, if you're using a rangefinder camera. These often fall out of calibration after a while.
4Watch your ISO speed on digital cameras. Most digital cameras apply more noise reduction at higher ISO speeds; sometimes this smears subtle textures and makes pictures look less sharp than they are. Turn off noise reduction if it affects the sharpness of your pictures. Don't shoot at high ISO speeds in daylight. If you have a top-end DSLR (like the Nikon D3 or Canon EOS-1Ds Mark III), you don't have to worry about the ISO speed.
5Use the Continuous Shooting mode. The camera will move slightly as your finger overcomes the resistance of pressing the shutter button. Also, if you have a DSLR camera, the movement of the mirrors in the body will add to camera shake. You can avoid some of this by using the Continuous Shooting mode available on your camera. This mode will take images as long as the shutter button is held down. In addition to avoiding camera shake from the initial button press, you will also have a choice of which image is best.
6Use your "Unsharp Mask" plugin in Photoshop, GIMP, or your favourite image editor. This won't make up for poor focus, camera shake or the spherical aberration that often comes with shooting lenses wide open (these are all way too complex phenomena to correct this way), but it will give it a bit of a sharpness "kick". Use a small radius (perhaps a pixel or less) and a large amount. If you're clever with layer masks, do this selectively so that only the parts that merit your viewer's attention are extra-sharp (hint: gaussian blur your layer mask with a very large radius).Ad
We could really use your help!
- You can use a flash whenever you're in range, even (and especially) in full light. The extremely short duration will not only fill in shadows but also freeze fine details like individual hairs making the entire photo look sharper. Two or more flashes are better than one for this effect. Use the flash on the camera and one on a handle too.
- Many web browsers display images at 100% resolution, so you can open an image with your web browser if you want to view it at 100%.
- If you must buy a new lens, and this article rightly assumes that most lenses are sharp enough when used properly, then consider going for a prime lens (lens with a fixed focal length, meaning you cannot zoom). Lenses like 50mm f/1.8 on a cropped sensor camera are popular, cheap, sharp, and great for portraits. Normal lenses (50mm equivalent on a 35mm film camera) are useful in a wide range of situations. On the cheaper Nikon and Canon DSLRs, a normal lens has a focal length of about 35mm. Primes tend to be sharper, cheaper, and faster (you can use a faster shutter speed). But don't buy another lens to make your pictures sharper unless you've played with all the things mentioned.
In other languages:
Thanks to all authors for creating a page that has been read 159,827 times.


How will driverless cars affect our cities?
Who will you meet?
Cities are innovating, companies are pivoting, and start-ups are growing. Like you, every urban practitioner has a remarkable story of insight and challenge from the past year.
Meet these peers and discuss the future of cities in the new Meeting of the Minds Executive Cohort Program. Replace boring virtual summits with facilitated, online, small-group discussions where you can make real connections with extraordinary, like-minded people.
Driverless cars are an imminent reality
Google is the most conspicuous developer of autonomous vehicles, but it is hardly alone in pursuing this venture. Most automakers are competing to introduce their own driverless cars to the public, and are doing so piecemeal, system by system. The components of the upcoming driverless car are being introduced into current models as ever more elaborate mechanisms to aid the driver, such as self-parking features and automated collision avoidance systems. Recently, a group of researchers at Oxford University developed a self-driving system which can be installed in existing manually driven vehicles, and whose cost is hoped to fall as low as 150 dollars within a matter of years.
Driverless cars will dramatically affect urban form, in two ways
Many anticipated consequences of driverless cars have already received attention on this blog and elsewhere, such as their impact on the mobility of the elderly, on taxis and car sharing services and on the future of the car industry. A crucial aspect which has escaped attention is the impact of driverless cars on urban form, which I anticipate will follow two broad predictions:
- Cities will greatly expand, again: Faster and more efficient transportation will convert locations that are currently too remote for most users into feasible alternatives, abundant with space. Like suburban rail in the early twentieth century and the mass consumer automobile that followed, driverless cars will generate a gradual, but dramatic expansion of cities.
- Buildings and parking will be uncoupled, freeing up valuable land: After dropping off passengers, driverless cars will independently seek parking (or their next car-share customers) and they will show up for the return ride at the tap of an app. As soon as driverless cars are common enough, the demand for adjacent parking will dwindle and parking lots in areas where land is sufficiently valuable will be ripe for conversion to other land use. As parking in high-value areas is thinned out or altogether purged, the micro-structure of cities will change – you guessed it – dramatically!
Why will cities expand?
Driverless cars will make it less “costly” for people to travel a given geographic distance, partly because they will be free to engage in other activities while travelling, but primarily because of reductions in travel time. Unlike human drivers, autonomous vehicles will follow optimal routes given real-time traffic conditions without fail. More crucially, as soon as suitable roads such as freeways (or lanes thereof) are declared off limits to manual driving, driverless cars will travel – safely – at much higher speeds than we do today. Gains in efficiency will follow from coordinated traffic management protocols, too. Once vehicles communicate with each other traffic through intersections and merges will flow much more smoothly than permitted by today’s traffic signals, stop signs and merging lanes, leading to substantial gains in travel time (a partial, human-mediated step in this direction is explored in this article).
If people currently forego affordable, spacious dream homes because the associated commute is too long, a technology that condenses the time needed for commuting along the same route – and allows doing so in the back seat – will make those homes more agreeable. Similarly, businesses whose location depends chiefly on access to appropriate labor or clientele will find that potential locations which are currently too remote will become feasible. It will still be crucial for them to sit “close” enough to their talent pools or their customer base, but because what matters for “closeness” is travel time rather than geographic distance, these firms will be able to reap the benefits of more remote locations without giving up “closeness.”
How far will cities expand?
The extent to which cities expand will be determined by the extent to which travel times are reduced. The more efficient traffic flow becomes the broader the geographic range in which living and working becomes feasible.
Will we ever hit a point at which people are no longer interested in the extra space offered by more distant locations? This is unlikely. Today swimming pools and three car garages are common in suburban homes, but who would have imagined that possible before the advent of the mass consumer automobile? Perhaps the current equivalent is the wish voiced by some home buyers – typically just beyond the urban fringe – that neighbors’ homes be out of sight. That seems like a lot to ask in today’s suburbs, but it could well become the norm looking forward.
When will this happen?
Most estimates suggest that the arrival of the fully self-driving car on the consumer market will occur within a decade. Provided that it will be possible to install these systems in existing manually driven cars – much as hands-free cellphone devices can be installed today – then there will be no need to wait for the entire stock of cars to gradually be replaced, and a much faster process of adoption will ensue. The speed of the process will be determined by people’s willingness to give up the driver’s seat, and by the adaption of the legal environment, first to permit driverless cars and then to secure them an exclusive right of way (a separate lane on the freeway). Google and the automakers will go to great lengths to ensure that legal barriers are removed and that the driverless car is adopted quickly. The devotion of a separate right of way may be a more challenging feat, but it will be difficult to reject in light of the gains it will offer.
Following these developments, the gradual process of city expansion will take place over many decades, much as the ramifications of the mass consumer automobile continue to play out almost a century after its arrival.
Is this good news or bad?
Ultimately, the accelerated drift of the city past the current metropolitan fringe implies sprawl on an unprecedented scale. This is unwelcome news for those readers who, like this author, share a romantic view of dense urban life. But there is good news as well.
In his 1991 classic, “Edge City”, Joel Garreau wrote that it is “the suburban home with grass all around that made America the best-housed civilization the world has ever known.” If the widely spaced mansions of the future are to today’s suburban home what today’s suburban home is to yesterday’s urban tenement, then we are in for a glorious improvement in our material welfare. But this grates the city lover’s ear and there is good news for city lovers, too.
The uncoupling of buildings and parking
Once most people stop driving manually, there will be a far less compelling need for buildings and parking to be adjacent. This does not mean that all parking lots will be converted to other land use – the total need for parking will only be reduced if other developments like increased car-sharing take off. But it does mean that parking lots on the most valuable land will be available for infill development. Driverless cars will gladly navigate to abundant off-site parking that will substitute for the lost parking on less valuable land.
The places in which infill development takes place will become denser and more walkable. The busiest suburban shopping districts will probably be among the first to see their parking built upon, as will clusters of suburban office towers which often spread out over vast areas. In so doing these areas will attain a more urban feel.
Of course the broader environment will remain suburban, but the local clusters of walkable density we have today – primarily old town centers engulfed by sprawling metro areas – will be joined by a new breed born of formerly pedestrian-free suburban centers and infill development upon parking. Given that the overwhelming majority of dense walkable areas in this country were built before World War II, a new generation and breed of walkable locations is rather exciting.
And what about the carbon footprint, you ask?
Traveling greater distances at greater speeds will require more energy. Full stop. Car sharing will not undo this in spite of reducing the total number of cars, because car sharing essentially only does away with the time cars spend parked.
Under the pessimistic premise that each car continues to emit greenhouse gases at current rates, the effect of driverless cars on urban form spells out a magnified carbon footprint. But technology is not stagnant. Today’s gasoline powered cars are already far more efficient than they were even a decade ago, and the ongoing transition to electric vehicles means that the energy needed for traveling greater distances at greater speeds will no longer need to come from fossil fuels. Instead, cars can be powered by any source of energy used to produce electricity, including more sustainable alternatives.
Contrary to the intuition that associates rapidly advancing sprawl with environmental disaster, persistent progress in sustainable energy could ultimately dissociate the suburban lifestyle from the greenhouse gas emissions it implies today, severing an important link between sprawl and climate change. The crucial question in this respect is whether the greening of our energy will precede the brunt of our cities’ future spatial expansion or not.
Leave your comment below, or reply to others.
Please note that this comment section is for thoughtful, on-topic discussions. Admin approval is required for all comments. Your comment may be edited if it contains grammatical errors. Low effort, self-promotional, or impolite comments will be deleted.
Read more from MeetingoftheMinds.org
Spotlighting innovations in urban sustainability and connected technology
Since the Great Recession of 2008, the housing wealth gap has expanded to include not just Black and Brown Americans, but younger White Americans as well. Millennials and Generation Z Whites are now joining their Black and Brown peers in facing untenable housing precarity and blocked access to wealth. With wages stuck at 1980 levels and housing prices at least double (in inflation adjusted terms) what they were 40 years ago, many younger Americans, most with college degrees, are giving up on buying a home and even struggle to rent apartments suitable for raising a family.
What makes it hard for policy people and citizens to accept this truth is that we have not seen this problem in a very long time. Back in the 1920s of course, but not really since then. But this is actually an old problem that has come back to haunt us; a problem first articulated by Adam Smith in the 1700s.
More than ever, urban transit services are in need of sustainable and affordable solutions to better serve all members of our diverse communities, not least among them, those that are traditionally car-dependent. New mobility technologies can be a potential resource for local transit agencies to augment multi-modal connectivity across existing transit infrastructures.
We envision a new decentralized and distributed model that provides multi-modal access through nimble and flexible multi-modal Transit Districts, rather than through traditional, centralized, and often too expensive Multi-modal Transit Hubs. Working in collaboration with existing agencies, new micro-mobility technologies could provide greater and seamless access to existing transit infrastructure, while maximizing the potential of the public realm, creating an experience that many could enjoy beyond just catching the next bus or finding a scooter. So how would we go about it?
Dedicated anti-trafficking actors across the nation are trying to build better systems in big jurisdictions like New York, San Francisco, and Los Angeles, and in smaller but scrappy jurisdictions like Waco, Texas and Boaz, Alabama. They all share the same need, for stronger interconnectedness as an anti-trafficking field, and more collaboration.
The Forging Freedom Portal is a one-stop shop where a police officer planning a victim-centered operation can connect with their law enforcement counterparts, and the right service providers ahead of time, collaborating to make sure they’re planning for the language skills, social services, and legal support that victims may need. The portal is a place where the people who care most about ending human trafficking, who are doing the hard work every day on the ground, can learn from each other and share best practices to raise the collective standard of this work.


The Elements of a Manufacturing Bill of Material
If you are working in manufacturing or you are new to manufacturing, you may have heard many times the terms bill of material or “BOM” regularly. A bill of material is a structured arrangement of components or parts of a larger object, in particular, particularly complex products or assemblies.
The “Bill of Material” is the skeleton of a product defining every part comprising it. It is often represented in the form of a tree showing which components are part of each subassembly from the top-most finished good down through all subassemblies to the purchased raw materials.The bill of materials contains all the components, sub-components, and raw materials necessary to produce a good or provide a service, providing valuable aid in the management of the warehouse and the organization of supplies. It allows for a concrete framework on the raw materials needed for the production of a finished manufactured product.
BOM information is one of the most important data structures of a manufacturing company because it documents components for every particular product manufactured and sold by the organization. The bill of material is needed not only for manufacturing planning but also for purchasing and scheduling since many items the bill of material do not need to be on-hand or in stock when new manufacturing orders are released because the bill of material is time-phased and parts are ordered or manufactured just in time for the next operation requiring their use.
The BOM will follow particular principles:
- It will bring together all the components necessary for the manufacture of a product.
- Each component, subassembly, and raw material will be identified by product code.
- A specific product code must identify each product variant described in a BOM.
- The BOM also defines the quantities required per component. For example, it may take 4 screws or bolts to fasten a part to a larger assembly.
- The BOM may also contain data for the materials used that is essential for engineering. For example, the tensile strength or chemical composition of some materials (or lots of material) may need to be defined for particular assemblies. This is especially true in highly regulated industries such as nuclear, automotive, aerospace and defense, etc.
The bill of material may also contain other data helpful for manufacturing planning. For example, some items must be sourced or purchased from specific vendors. As such, the BOM may reference a particular supplier. Some BOMs must also utilize materials with specific attributes. These materials are purchased or manufactured to inventory and then the attributes of those inventory lots are used to determine which specific materials to utilize in work orders referencing the specific bill of materials with attribute requirements. For example, a specific bill of material may require the use of metal products with at least 5% zinc content.
The bill of material presents a uniform product structure with common product-related data that is supplemented by user-specific data. The common product-related data includes the part number, the parts designation, the unit of measure, and the respectively required number or quantity as well as the hierarchical arrangements of the components.
All users from the various specialist areas of a company (production, procurement, logistics, sales, finance, etc.) access this uniform product structure, while the respective departments can only access the application-specific data. For reasons of security and clarity, the departments have different access rights and one each application-specific view of the BOM data.
BOMs can be evaluated and sorted by product and application according to various criteria. Variant BOMs must obtain only the required information for each product variant. BOMs are especially needed for deterministic needs assessment, work planning and preparation, and the creation of work instructions.
Bills of material often start during the original part design process in computer aided design (CAD) systems. These engineering bills of material (also known as eBOMs) represent the designed structure of the item. They are then recreated manually in an enterprise resources planning or ERP business system as the manufacturing bill of material or mBOM. There could, and often are, differences between the eBOM and mBOM. For example, the engineer may have used a generic part or component as a placeholder during the engineering process but the manufacturing bill of material may define the exact parts to be used. Further, an engineering drawing may utilize a stocked subassembly which is not necessarily defined down to it’s individual components in the CAD application. But in ERP, the subassembly bill of materials must be defined in the mBOM for accurate material planning and production scheduling.
Some ERP systems utilize other types of bills of material. These can range from a sales BOM which is sometimes called a kit containing components that are typically not “assembled” until ordered by the customer as well as template bills of material which are used as a basis for creating new bills of material for similar items. Another bill of material type commonly used in manufacturing is the phantom bill of material. Phantom bills of material represents the components for an assembly that is never manufactured to stock. Instead, the bill structure is inserted into other bills of material to manufacture the assembly during the larger production of a finished good. For example, you may have a phantom bill of material for a power supply. You never create work orders to make the power supply by itself but every time you create a work order to make any type of machinery or equipment the bill of material will reference the phantom BOM and insert the components and operations required to make the power supply during the overall manufacturing process. Phantoms are sometimes also known as blow-through, transient, or pseudo bills of material.
Looking at the physical structure, the basic types of BOM includes the structure BOM, the modular BOM, the single-level BOM, and the complex or multi-level BOM. The distinction mainly refers to the concrete representation on the screen or in an expression. ERP systems generally store parts list information in the form of a building block BOM, because all other required types can be generated from this by vertical BOM.
For complex products that are produced in flow production (e.g., automotive industry), you can often find the structured BOM from which you can also generate building block BOMs and usage statements.
A structural parts list contains all assemblies, individual parts, and raw materials of a product and shows the composition of a product in tabular form across all production stages. It corresponds in its information content to the product structure. The quantities refer to the total product or each unit of quantity.
Single-level or building block BOMs are distinguished by the fact that only one level of the product structure is considered at a time.
In a modular bill of materials, several bills of material are summarized on a form according to DIN 199-1: 2002-03 to be able to list different objects with a mostly high proportion of identical components. In an electronic parts list system, the various product variants are stored together with the different options of the parts and assemblies. One or more attributes distinguish each product variant.
These respectively applicable attributes are then stored in the corresponding parts and assembly variants, so that a correct assignment to the product variant is possible.
The configurable BOM also called selection BOM or maximum BOM, is a variant of the variant BOM in which all variants of a product or assembly are mapped together. To be able to differentiate between the configurable and to assign the parts and assemblies to a single, specific product variant, these must be provided with product-related attributes. These attributes are features that describe the product in more detail.
A particularly useful type of attribution is the specification of an algebraic expression that refers to a set or subset of the product variants. It requires an algebraic product definition (product encryption) with the help of features. Depending on which product is concerned, features can relate to the equipment, functions, colors, materials, or even geometric, physical or chemical properties of a product.
The features may either have only a loose relationship with each other or form a structure in the form of an algebraic union. This type of product definition is found mainly in industries producing complex and varied products. In the automotive manufacturing industry, the vehicles are described by a large number of features that can be selected with the aid of product configurators. Accordingly, many vehicle manufacturers use algebraic complex parts lists. Depending on the specific form of the product definition, these then differ in the type of attribution.
A multi-level bill of materials is a bill of materials that lists the components, assemblies, and parts essential to make a product in a parent-child, top-down method. From a specific lot size, the quantities of one or more materials change, or new components are added, then this multi-level BOM is converted into a multiple BOM. Thus, alternatives to the original parts list are formed. These are also called multi-level BOMs.
As a whole, the BOM makes it possible to monitor the costs for the procurement of raw materials and labor (based on the time needed to complete the production process).
There are a lot of different types of bills of material and CADTALK works with all of them. CADTALK leverages artificial intelligence to transform the eBOM from CAD to mBOMs in your ERP system in seconds allowing your engineers to do what they do best –create great products.


The world around us is amazing with a variety of different mysteries. One of the keys to the mysteries of the universe is numbers. As far back as Pythagoras said: “The world is built on the power of numbers.”
In my school course I studied the signs of divisibility by 2, 3, 5, 9, 10. This is not enough and I decided to expand my knowledge on this subject. That is how the work on this topic began.
In studying the topic: “The signs of the divisibility of natural numbers by 2, 3, 5, 9, 10” we were interested in the question of the divisibility of numbers. It is known that not always one natural number is divisible by another natural number without a remainder. When dividing natural numbers, we get a remainder, we make mistakes, as a result – we lose time. The signs of divisibility help, without doing division, to determine whether one natural number is divisible by another natural number. We decided to write a research paper on this topic.
To supplement the already known signs of the divisibility of natural numbers studied at school and to add to their knowledge of the signs of the divisibility of numbers.
1. To investigate additional literature that supports the hypothesis of the existence of other characteristics of divisibility of positive integers and the validity of our identified characteristics of divisibility.
2. Write out the signs of divisibility of natural numbers in 7, 11, 12, 13, 14, 19, 37 found from additional literature.
3. Draw a conclusion.
If the divisibility of natural numbers by 2, 3, 5, 9, 10 can be determined, then there must be signs by which the divisibility of natural numbers by other numbers can be determined.
We encounter numbers at every step, they accompany us from birth to old age.
At school in math classes, we study different numbers and perform operations with them. Often we have to do division to solve a problem.
From mathematics lessons, I learned about the divisibility of numbers by 2, 3, 5, 9 and 10. According to these rules I can now, without doing division, find out whether a given number is a multiple of, for example, two or nine.
In the decomposition of numbers into prime factors I had to divide the number by 7. How do I know if I am dividing with or without a remainder? Are there no signs of divisibility by 7? What about other numbers?
I found a definition of the divisibility sign in an encyclopedic dictionary.
Divisibility is a rule that allows you to quickly determine whether a number is a multiple of one or another number.
With the help of the Internet and additional literature, I have found the signs of divisibility of numbers, which I have not studied in school program:
1) A number is divisible by 7 when the result of subtracting the doubled last digit from that number without the last digit is divisible by 7
(For example, 343 is divisible by 7 because 34- (2*3) =34 – 6=28 is divisible by 7).
I also discovered another way:
2) To find out whether the number is divisible by 7 , divide it from the right hand into faces of 3 digits in each; make the sum of the faces of odd order and from them subtract the sum of the faces of even order (or vice versa). If the difference is divisible by 7, then the number is divisible by 7.
While working on this topic, I learned that there are a couple of very different signs of divisibility by 11.
1) If the sum of the digits in the even places is equal to or greater than the sum of the digits in the odd places, then the number is divisible by 11.
(For example, 14641 is divisible by 11 because 1+6+1=4+4.)
2) The number is divided from right to left into groups of two digits in each group and the groups are added. If the sum obtained is a multiple of 11, then the number is a multiple of 11.
In order to find out whether the number is a multiple of 12, you should check whether it is divisible by 4 and by 3 at the same time.
(For example, 24 is divisible by 4 and by 3, so it would be a multiple of 12.)
So far I have only found one sign of divisibility by 13. It is similar to divisibility by 7, only the last digit should not be doubled, but multiplied by 9.
(For example, 361 is divisible by 9, because 36 – (1*9) = 36 – 9 = 27 is divisible by 9.)
The number that is divisible by 14 can be tested by the same scheme as in 12. Only the number must be divisible by 7 and by 2.
(For example, the number 42 is simultaneously divisible by 2 and 7).
A number is divisible by 19 if and only if the number of its tens added to the doubled number of ones is a multiple of 19.
(For example, 646 is divisible by 19 because 64 + (6 × 2) = 76 is divisible by 19.)
A number is divisible by 37 if and only if, when you divide a number into groups of three digits (starting with ones), the sum of those groups is a multiple of 37.
Signs of divisibility apply to a variety of number focuses. For example:
One person writes down any three-digit number on a piece of paper. Passes it to the other person. The second person adds the same number to the right side of the number and passes this entry of a six-digit number to the third person. Let the third divide this number by 7 and pass it to the fourth. The fourth will divide the result by 11 and pass it on to the fifth. The fifth will divide the result by 13 and pass it to the first. If all the calculations have been done correctly, the first will get the three-digit number he originally wrote on the paper. The surprise in this trick is not that the first one gets the number he wrote down, but that the “trickster” is sure that the number in question is divisible by 7, 11, 13 – which is not very common. The clue is that by adding exactly the same three-digit number to a three-digit number, it is equal to multiplying by 1001. And 1001 equals the product of 7, 11, 13.
I decided to do a survey of my classmates to see if they know the signs of divisibility, such as 7, 11, 33, 14, and whether they want to learn them. The boys’ answers pleased me. It turned out that most of them, like me, want to learn more about the signs of divisibility, this topic aroused their interest.
After learning many other signs of divisibility, I made a conclusion:
Working with different sources, I became convinced that there are other signs of divisibility of natural numbers (by 7, 11, 12, 13, 14, 19, 37), which confirmed the correctness of the hypothesis that there are other signs of divisibility of natural numbers.
Knowing and using the above signs of the divisibility of natural numbers greatly simplifies many calculations, thereby saving time; eliminating computational errors that can be made when performing the action of division. It should be noted that the wording of some of the signs is difficult. Maybe that’s why they are not taught at school.
After getting acquainted with the signs of divisibility of numbers, I believe that I can use the acquired knowledge in my own learning activities, independently apply this or that sign to a particular problem, apply the studied signs in a real situation.
I searched for information on this topic in an encyclopedia and online sources. Everything I found will help me in solving the examples, make my work easier and faster.


To edge against market volatility large buyers often strike deals with individual oil producing countries, at a price different from the market.
STEVE AUSTIN | 2014/05/05
Did you ever wonder what makes the price of oil move and why movements in the price of oil don't always feed through to the gas station's prices? Who decides the price of oil and how do all the oil businesses in the world hedge against sudden movements in the price? Although there are well known oil price indices in the world, the mechanism that sets their levels involves a range of factors from politics to transport networks. Buyers of oil for physical delivery rarely pay the price listed on the WTI index or the Brent crude index. In this article, we take a look at how crude oil prices are calculated and why gasoline prices are not always linked to the price of crude oil.
The price of oil as discussed in the news is the price of a commodity different from the gasoline you fill your car with; it is in fact crude oil. Crude oil is the base product that gets processed into gasoline at oil refineries. So, if the price of oil goes up, the price of gas goes up. However, there are a number of other factors affecting the price of gasoline and that's why the gas price doesn't always fall with the price of oil. Refining capacity can rise and fall. If a major refinery develops problems and has to shut down, then the amount of gasoline that can be produced falls. The price of gasoline rises because of shortages, but the price of crude oil will fall because of gluts.
Transport costs can also affect both the price of crude oil and the price of gas as the oil needs to be taken to the refineries and then the gas needs to be distributed from the refineries to gas stations. So if the price of transport rises significantly on any stage of this supply chain, the pump price of gas will increase irrespective of what the price of crude is doing.
The USA consumes much more oil than it produces, so if some major oil producing countries unexpectedly withdraw their oil from the market as happened during the 1973 oil crisis, the economies of the USA and the developed world can suffer long-term damage. For this reason, the Federal government created a vast oil storage facility called the Strategic Petroleum Reserve, or SPR. The President can take the decision to release oil from this reserve to balance out any sudden drop in the supply of reasonably priced oil. Thus, the nation has a mechanism to protect against sudden spikes in the price of oil. To limit consumption, state and Federal governments can increase the price of gas by imposing taxes and levies on oil companies, refineries and gas stations.
Oil refineries buy their crude oil by the barrel. Let's say a refinery buys 1,000 barrels of oil for delivery and a set of trucks filled up with oil drums starts rolling in its direction. Surprisingly these trucks will not be carrying 1,000 drums of oil because the volume of a (standard) oil drum differs from the volume of an oil barrel: 55 gallons for an oil drum versus 42 gallons for an oil barrel. Hence the trucks will be carrying 763 drums of oil (same volume as 1,000 barrels of oil, just fewer drums). Think of a barrel more as a unit of measure, like a gallon or a litre rather than as a container. When you hear talk of the price of oil, that price is given per barrel, which is abbreviated to "bbl." A barrel of oil is the equivalent of 42 gallons, or 159 litres. Thus, if you read that the price of oil is $104 that means for 42 gallons of crude oil.
Anyone can strike a deal and there is no law dictating the price. However, whenever you buy something, you want to know what the going rate for that item is, and the oil industry is no different. There are a number of published indices around the world that the oil industry uses. The first of these is the West Texas Intermediate price set at the New York Mercantile Exchange. The second is the Brent Crude Index, which is set at the Intercontinental Exchange in London and the third is the OPEC Basket, which is an average of the prices achieved in all OPEC countries and is managed from OPEC's headquarters in Vienna.
Each index rises and falls depending on how many people want to buy oil on that particular day. Many of the people who invest in oil at these exchanges never actually intend to take delivery. These people just want to buy a contract at a low price and then sell it on at a higher price. When speculation enters a market then many new factors enter the pricing structure. Political uncertainty in some part of the world could disrupt supply and so the price goes up. Trade figures of a major manufacturing nation, like China, might show that country is slipping into recession. That would reduce demand for oil, thus the price would fall on all the indices in the world.
Countries that produce more oil than they consume, like Saudi Arabia and Russia, like the price of oil to go up. Countries that produce little oil, like Japan and Italy, like the price of oil to go down. In the US, it would be in the general economy's interests for oil prices to be low, but a low oil price would damage large American corporations that have influence with national politicians through election fund contribution and targeted job creation. Thus, some countries may try to drag the price of oil down, while others may try to force the price up. Politics, then, plays a major role in the price of oil registered on these indices.
Other investor-related factors may also influence the price of crude oil. The banking crisis of 2008 saw savers looking for places to store their money when it looked like banks might go bust, so they poured money into commodities, including oil. Thus, the price of oil rose despite a general collapse in demand. Speculators like volatility because they then don't have to wait too long before they can sell on their investments at a higher price. Speculators, and the information providers that support them, over-react to world news to try to force dips and peaks so they can buy and sell. Thus, there are many non-oil related factors that can influence the price of oil set on the three main indices.
Buyers of oil for delivery rarely pay the index price. However, the price of a particular index is a factor in the contract price mechanism. Not all oil in the world is the same. Some oil is quicker and cheaper to refine than others. Thus, you would likely pay more for oil that is easy to process, than for oil that is expensive to process. The location of the oil and transport capacity is also a factor. A contract to buy oil in Saudi Arabia would carry a lower price than a contract to buy a tanker load of oil that is just off the coast from a refinery. Therefore, the two factors of oil properties and location influence the price paid on contracts for delivery regardless of what the price of WTI or Brent crude is.
Oil companies understand the short-termism of speculators and so oil price contracts tend to work on the average price over a certain period. Rather than striking a price at the Brent Crude Index price on the day of delivery minus $3, a contract is more likely to take the price from the index averaged across the week of delivery and then apply a premium or a discount. This avoids a buyer being hit by bad news on the day of delivery jacking up the Index for a few days.
Although the WTI index is based in America, the Brent Crude Index is based in Europe and the OPEC Basket is based mainly on oil prices in Arabia, contracts for oil do not have to rely on the price of the closest Index. Thus, American buyers may strike a price based on the Brent crude index, even though they are buying oil from Arabia.
All these factors boil down to oil price indices operating as "benchmarks" for the oil industry rather than a common price. The relative movements of the indices do affect the price oil companies charge for oil, but the actual price is a matter of individual contracts accounting for many different factors rather than a global standard price.
The index prices of crude oil are important throughout the oil industry. However, if you are interested in how much buyers actually pay, do research the contract terms arrived at for individual deals. For example, the China National Petroleum Corporation recently signed a joint venture with the UAE's Abu Dhabi National Oil Company. This deal would undoubtedly grant cheaper oil prices to China than those listed for the OPEC Basket, of which Abu Dhabi's oil market is a constituent. Taxes, politics, transport networks, geography, economic expansion and the weather all play a part in the complex calculation of setting the level of oil price indices. However, deal-making, contract conditions, side benefits and commercial interests override all other factors when setting the price for individual oil supply contracts.
Published on 2014/05/05 by STEVE AUSTIN


UCI Contracted to Develop Space Gym
NASA recently granted UC Irvine researchers $1.5 million to construct a fitness apparatus to keep astronauts healthy in space.
The Yo-Yo inertia Wheel Technology, named for its resemblance to the childhood favorite, was built to maintain muscle tone while providing a workout in space. Bearing resemblance to a rowing machine, in which the user pulls a weighted bar from feet to chest while sitting. The Yo-Yo would provide astronauts with resistance training that is similar to that done on a rowing machine.
Although astronauts have always been required to exercise on a daily basis, developing resistance training in the absence of gravity has proved difficult. Traditional aerobic exercise devices do not provide enough resistance to benefit the muscles, or even to reduce the negative effects of microgravity.
Microgravity, the condition in which lack of gravity results in weightlessness, quickly contributes to muscle loss and the degeneration of bone density.
While gravitational resistance constantly forces muscles and organs to work harder, microgravity renders muscles useless and decreases the intensity of other organs, such as the heart, which pumps less in the absence of the pull of gravity. The result is demineralization and loss of strength.
Furthermore, microgravity negatively impacts the nervous system. The legs, which are normally activated due to the pull of gravity, stop sending messages via neural pathways to the brain when in space. Decreased use negatively affects the feedback loops in the nervous system and contributes to atrophy.
Although the effects of microgravity are mostly reversible upon returning to earth, the Yo-Yo ensures less of what is essentially an accelerated aging process of the bones and muscles, in addition to making the healing process of sore muscles easier on returning astronauts.
Under conditions where even barbells and dumbbells are weightless, the Yo-Yo exploits microgravity and creates resistance to target muscles and bones in longer flights.
“The Yo-Yo allows you to mimic weight squats, and you can get aerobic exercise through a rowing motion,” said Gregory Adams, UCI physiologist and head investigator of Yo-Yo experiments on campus.
Furthermore, the Yo-Yo does not require external power, and Adams said that he plans to make the device compact enough to fit into carry-on vehicles on space shuttles.
Adams has begun to test his fitness machine by asking local UCI students to experiment with it, specifically male students from the ages of 18 to 35 who do not exercise, smoke or have any types of brain, bone or heart disease. Volunteers must also be able to commit to five weeks of training, in sessions of two to three hours per week.
“I don’t see how this is beneficial,” said first-year undeclared student Raisha Kruckmeyer. “It sounds like too much money being spent for the wrong reasons … do astronauts really need a gym in space?”
First-year business economics major Yuliana Sanchez agreed. “The money that NASA is spending is from the government. The United States could use this kind of funding to help so many other problems facing our nation. It does not make sense how public schooling gets so many cutbacks while programs like this receive abundant funding.”
However, researchers around the world continue to test the device in the hopes of eliminating the possibility of broken bones and other problems for astronauts at the height of long-term missions.
Inventor Per Tesch has been researching the device for 15 years after being commissioned by the Swedish National Space Board and NASA.
The device was recently delivered by the U.S. space shuttle Atlantis to the International Space Station (ISS), the first in-space test. However, results are not expected for another couple of months.
Thus far, ground experiments with the device in training centers around the world have proved successful.
Tomasz Owerkowicz, a UCI staff member working on the project, asks anyone interested in volunteering to contact him at either email@example.com or at (949) 824-3356.


How can we nurture our innate ability to experience happiness? How do we define this elusive emotional state for ourselves? These are questions that many of us have considered, especially when we face situations like chronic stress, serious illness or loss.
“Just as pain serves as an alert for our bodies, we can be guided by being aware of commonly learned but ‘painful’ ways of thinking – or being with our feelings – that lead to unhappiness,” said Mark Roa, MA, LP, CBC, an integrative health psychologist at the Penny George Institute for Health and Healing.
In his work, Roa helps people who are facing health challenges, a disability, or significant anxiety or stress regain a sense of wholeness and happiness. “Those who study happiness recognize that it is associated with states of satisfaction and good self esteem, and also with the traits of gratitude and compassion,” Roa noted.
For Roa, happiness is strongly connected to our thoughts and our views of self. He has observed that all of us have learned thoughts and beliefs about ourselves, others and the world around us. Some of these are helpful and deserve our reinforcement, like maintaining the view that we are loveable. But others are very unhelpful, especially self-criticism or fear-based assumptions like, “I’ll never be good enough,” “They think I am weak and foolish,” or “I don’t fit in.”
“These seemingly automatic negative thoughts and beliefs require our gentle rethinking,” said Roa. This is the basis of cognitive therapy, but Roa believes that we can each incorporate some self-nurturing practices (see below) into our daily lives that can help foster feelings of happiness.
- Be aware of self-talk. Frequently ask yourself: What am I thinking? What am I feeling? Are these thoughts or feelings helpful to me or to others?
- Strive to adopt an intentionally compassionate, gentle and understanding view of yourself. This influences every aspect of your life positively.
- Practice mindfulness or being in the present moment. Learn how to let go of processing the past or anticipating the future.
- Consider, as needed, which is more detrimental to yourself: resentment or forgiveness.
- Don’t try to manage difficulties alone. Reach out to friends, loved ones and readily available supportive community resources. People truly want to help.
- In times of great distress, know that anxious and fear-based thinking increase the intensity of feelings, and intensity always passes.


British Royal Air Force (RAF) engineer officer and Air Commodore Sir Frank Whittle, OM, KBE, CB, FRS, Hon FRAeS was born 1st June 1907 . He is credited with independently inventing the turbojet engine (some years earlier than Germany’s Dr. Hans von Ohain) and is regarded by many as the father of jet propulsion. The Turbojet Engine was designed to overcome the limitations of traditional piston-engine turbo-prop engines, which could only fly up to a certain speed and height, because above that the air-flow was too fast and too thin for it to perform effectively. From an early age Whittle demonstrated an aptitude for engineering and an interest in flying.
Determined to be a pilot, he overcame his physical limitations to be accepted into the RAF, where his abilities earned him a place on the officer training course at Cranwell. He began his RAF career as an apprentice where he demonstrated an aptitude for engineering and an interest in flying. Determined to be a pilot, he was eventually accepted into the RAF, where his abilities earned him a place on the officer training course at Cranwell, where he excelled in his studies and became an accomplished pilot.While writing his thesis there he formulated the fundamental concepts that led to the creation of the turbojet engine, taking out a patent on his design in 1930. His performance on an officers’ engineering course earned him a place on a further course at the University of Cambridge where he graduated with a First.
Despite this success, official interest in the Jet Engine was limited, so Without Air Ministry support, he and two retired RAF servicemen formed Power Jets Ltd to build his engine with assistance from the firm of British Thomson-Houston. Despite limited funding, a prototype was created, which first ran in 1937 culminating in the historic flight of May 16th 1941 and leading the way for others. Official interest was forthcoming following this success, with contracts being placed to develop further engines, but the continuing stress seriously affected Whittle’s health, eventually resulting in a nervous breakdown in 1940 so he resigned from the board in 1946 In recognition for his acheivements Sir Frank was later knighted by King George VI and In 1948 Whittle retired from the RAF and received a knighthood. He joined BOAC as a technical advisor before working as an engineering specialist in one of Shell Oil’s subsidiaries followed by a position with Bristol Aero Engines. After emigrating to the U.S. in 1976 he accepted the position of NAVAIR Research Professor at the United States Naval Academy from 1977–1979. In August 1996, Whittle sadly died of lung cancer at his home in Columbia, Maryland on 9th August 1996, but his legacy lives on, and three examples of Whittle’s Jet Powered Gloster Meteor can be found at the RAF Aerospace Museum in Cosford.


Paramillo Tapaculo Scytalopus canus and Paramo Tapaculo S. opacus have been split following a decision by the AOU South American Classification Committee (http://www.museum.lsu.edu/~remsen/SACCprop446.html) based on recommendations made by Krabbe and Cadena (2010). Differences in vocalisations and the level of genetic divergence between these taxa support the view that they are sufficiently distinct as to be treated as separate species (Krabbe and Cadena 2010).
It is proposed that S. opacus, which ranges from the Central Andes of Colombia, south through Ecuador to northern Peru, be listed as Least Concern on the basis that it does not approach the thresholds for Vulnerable under any of the IUCN criteria. The species’s range does not approach the thresholds for Vulnerable under the range size criterion (Extent of Occurrence less than 20,000 km2 combined with a declining or fluctuating range size, habitat extent/quality, or population size and a small number of locations or severe fragmentation). The population trend appears to be stable in the absence of evidence for any declines and substantial threats, hence the species does not approach the thresholds for Vulnerable under the population trend criterion (at least a 30% decline over ten years or three generations). The population size has not been quantified, but it is not believed to approach the thresholds for Vulnerable under the population size criterion (fewer than 10,000 mature individuals with a continuing decline estimated to be at least 10% over ten years or three generations, or with a specified population structure).
Mapping by BirdLife of the known range of S. canus in the Western Andes of Colombia suggests that its Extent of Occurrence (EOO) is c.940 km2. This indicates that the species may be eligible for Endangered status under the B criterion. To qualify for Endangered the species’s habitat must be shown to be severely fragmented, i.e. over 50% of suitable habitat in patches too small to support viable populations, or occur at five locations or less, with an ongoing decline observed, inferred or projected in the EOO, Area of Occupancy, area, extent and/or quality of habitat, number of locations or sub-populations or number of mature individuals. Note that for the purposes of the Red List criteria ‘location’ defines a “geographically or ecologically distinct area in which a single threatening event can rapidly affect all individuals of the taxon present. The size of the location depends on the area covered by the threatening event and may include part of one or many subpopulations. Where a taxon is affected by more than one threatening event, location should be defined by considering the most serious plausible threat” (IUCN 2001). Krabbe and Cadena (2010) do not seem concerned over the conservation status of S. canus, pointing out that it occurs in two protected areas and may be present on other areas of páramo. However, these protected areas may offer little in the way of de facto protection (P. G. W. Salaman in litt. 1999). In general, the main threats to páramo habitats are livestock-grazing and fires set by tourists or to encourage vegetation to shoot (Wege and Long 1995, Kessler and Herzog 1998, P. G. W. Salaman in litt. 1999, Koenen and Koenen 2000).
Draft BirdLife range map for Paramillo Tapaculo
With all this in mind, further information is requested on S. canus, in particular the likely population size, estimated population trend, level of habitat fragmentation and the severity of potential threats.
IUCN (2001) IUCN Red List Categories and Criteria: Version 3.1. IUCN Species Survival Commission. Gland, Switzerland and Cambridge, UK: IUCN.
Kessler, M. and Herzog, S. K. (1998) Conservation status in Bolivia of timberline habitats, elfin forest and their birds. Cotinga 10: 50-54.
Koenen, M. T. and Koenen, S. G. (2000) Effects of fire on birds in páramo habitat of northern Ecuador. Ornitol. Neotrop. 11: 155-163.
Krabbe, N. and Cadena, C. D. (2010) A taxonomic revision of the Paramo Tapaculo Scytalopus canus Chapman (Aves: Rhinocryptidae), with description of a new subspecies from Ecuador and Peru. Zootaxa 2354: 56-66.
Wege, D. C. and Long, A. J. (1995) Key Areas for threatened birds in the Neotropics. Cambridge, U.K.: BirdLife International (BirdLife Conservation Series 05).