SMF

Tony McC and Sisyphus, what would be the physical mechanism that would damp the oscillations (e.g. reduce the kinetic+potential energy of the rock)? SM

Mrs Zeta, I think you should be more careful when referring to evolutionary processes. Nature doesn’t “need intelligence,” and in your article you say “Nature will follow whatever paths are necessary in order to increase hierarchical sophistication” and other similar statements that are, perhaps unintentionally, teleological, incorrect, and misleading to readers who are not familiar with evolutionary processes. Your thesis of “technology-assisted human intelligence” that leads to an extended lifespan is fun and has been explored (with less biomedical factual support) in science fiction. However, a species can eliminate itself by overpopulation, environmental degradation, and resource depletion, and we humans appear to be working very hard to accomplish this very thing. Even, without extinction, these factors could easily disturb technological society enough to stop the hypothetical progress you suggest. SM

Brew lots of beer in the greenhouse.

The only way to force evolution would be to start another nasty eugenics movement and only allow children whose parents live the longest to breed. This would probably show some results in several thousand years. SM

It turns out that a frictionless object dropped into a theoretical tunnel connecting any two points on the surface of the earth would fall through in close to 42 minutes. This idea goes back to Newton, but was explored by Paul W. Cooper, "Through the Earth in Forty Minutes," American Journal of Physics, January 1966, Volume 34, Issue 1, pp. 68. The Time Magazine story about him is here: http://www.time.com/...,842469,00.html Simple math: http://www.docstoc.c...y-Train-Project More complex math for the shape of the fastest tunnel: www.physics.unlv.edu/~maxham/gravitytrain.pdf SM EDIT- I don't know why the PDF doesn't come up as a link, but it works as cut and paste.

Ethereally Luminous, there is no way to beat the theoretical maximum. Capacitors and the magical suppressed automobile carburetor can't surpass what is possible. A human uses about 100 watts just to stay alive and can sustain production of around 0.1 horsepower on an exercycle. You could probably recharge your cell phone as a part of your exercise program, or run a blender for a short sprint, but this is just not a practical proposition unless we bring back slavery. If you want to recharge a battery as a hobby, go for it. There are quite a few folks who do this and I respect their determination. Just don't think that it is going to change anything but one's average level of health. SM

Here is another factoid regarding this idea- The transit time from the north to the south pole, or the opposite, is slightly less than 42 minutes. Another question- In this transition, what is the region of maximum and minimum acceleration? SM

A rechargeable battery could be maintained by a variety of human powered generators, but humans can't produce a lot of electricity. This idea works fine with very low power digital radios and flashlights, but otherwise figure out how much energy is required and how long it would take to recharge your battery powered electric tool, or run your stereo. I have better ways to spend my time, but it would make a pretty good exercise program. SM

Whole milk is what is left over after removing most of the butter fat so that it has 3% to 4% fat (depending on the country). Condensed milk has the milk proteins of milk concentrated and the fat content is around 7%. Heavy cream, in the US, has at least 36% fat. There are various recipes for mixing condensed milk, whole milk, and thickeners to replace heavy cream in cooking, but in my opinion the flavor suffers greatly. Your mileage may vary. SM

If there was no friction or other factors that would interact with the rock, it would bounce back and forth indefinitely. At the least, this would require a perfect vacuum in the tunnel and a rock made of material that didn't interact with the earth's magnetic field. SM

Marat, your view regarding body donation and gross anatomy courses is very distorted and unfair. I am not a gross anatomist, but I have around 30 years of experience with these programs and first year medical students (in the US), and I have found that 99% of medical students would be very angry at the example you provided. There are always a few unethical clowns that get into medical schools from time to time and they are almost always flushed out because indignant students report their activities. In fact, it is these incidents that serve as necessary important teaching moments for faculty mentoring. Your description of the application process is not as severe in many states but it is not medical ethics gone awry, it is due to our contentious and litigious society. A typical problem is due to some members of the family of the deceased who disagreed with, or were not informed of, the plans of the relative who wished to donate their body to society or a medical school that helped them with their own or a loved one's illness. Without extensive documentation of the donor's intentions, his or her angry relatives and a lawyer can overturn the donor's decision regarding his or her own body. SM

In the US, call the anatomy department of your most local, or preferred, medical school and they will have someone whose job is to answer question, and who will send you an information pack regarding body donation. It does have to be set up ahead of time to minimize the period between your death and chemical preservation of your tissue in order to minimize degradation, and some departments prefer preservatives that are different from that used by the typical embalmer. You should be aware that very few donations are accepted for the study of specific medical conditions and depending upon the condition your donation may be denied. Most cadavers are used for training medical students in a gross anatomy course and there is concern about infection that students might contract, and the desire to have a complete normal body for study. Anatomical boards in different states have different rules regarding donation, and some take all donations whether they are usable or not. At most medical schools there can be research projects that require tissue from the gross lab and you can ask the body donation representative about this. Donating ones body is a wonderful gift and all medical schools specifically train medical students to respect this donation and take their anatomical study seriously. SM

The question is-- Have any of the nontraditional therapies, for which there is no known mechanism to explain how they might cure an organic condition, or the mechanism is just magical thinking (e.g. Homeopathy or acupuncture), been shown by a reliable scientific trial to be effective? SM

Scilearner, you are correct that rotating the water container doesn't rotate the water, at least directly. Newton's first law of motion says that stuff (pardon the informal language) stays still, unless it is moved by something, and once moving will continue until something stops it. The water glass, and your semicircular canals, connect to the fluids they contains by friction with the walls of the containers. A smooth water glass will not have very much friction with the water and it takes a while for the moving glass to cause the water to turn. If you made a glass with a rough internal surface the water would catch up with the rotating glass much faster. A semicircular canal has quite a bit of friction between its internal membrane and the fluid (endolymph), because there is much more surface area, relative to the endolymph volume, than a glass of water. This friction relationship has been evolutionarily tuned to give the best sensory function for typical head movements, and this gets fooled when you get dizzy. Here is some added information. You can move your head all around and up and down while looking at some place on a wall, and your visual world will appear to stay still and constant. We all take this for granted, but if you took a video camera and rotated all around while holding the camera to your body the video you made would be an impossible to watch blur. To make a good video you would have to try to keep the video camera pointed at exactly the same place on the wall while you rotated, and this is hard to do. How about if you were sitting in a desk chair and somebody else turned you back and forth irregularly, keeping the camera straight would be impossible. This is the problem that your visual system has to deal with when you turn your head or walk around. There are several mechanisms that help you keep your visual world steady while you are moving and the most important one is the input from the semicircular canals that tell your eyes to counter-rotate when your head rotates. It is amazing that this system is so accurate. When you spin until you get dizzy, and the world seems to be spinning around you, the endolymph keeps moving and your visual-motor control system thinks you are turning when you are not. What this tells you is that you are a well tuned device and someone who has had an infection in, or damage of, their vestibular system can tell you about the horrors of having this system broken.SM

Asking "why" regarding evolutionary processes can sometimes get you into problems. There are other energy carriers, including GTP, but ATP is the main one. Phosphorylating AMP, or more commonly ADP to make ATP is a relative simple reaction. When ATP is is hydrolyzed back to ADP, the inorganic phosphate is often donated to a protein that, when it binds, causes it to change its conformation to perform some function. For example, a membrane channel or pump can open and pass molecules into or out of a cell., or the conformational change might regulate the activity of an enzyme. SM

Precession adds a little variability to the tilt over long time periods.

Swansont, what is the coordinate system that deals with angular acceleration as linear? I read a fun piece a while back that talked about the use of centrifugal force as being appropriate for some engineering problems, but the coordinate system of a physicist observer looking at rotating objects from outside the system, would require that centrifugal force be fictive, while centripetal is not. Similarly, because atmospheric physicists are rotating within the earth coordinate system, Coriolis force is a useful concept, but a physicist observer outside the earth coordinate system would say it is fictive. Then along comes Einstein, and from his viewpoint, at least in terms of orbiting systems, gravitational force is fictive. This is a slight divergence from the thread, but I find the notion of coordinate systems and their generalized everyday analog, “frames of reference,” is fascinating. SM

Marat. There is a recent research article that checked whether the placebo effect would work if the patient was informed that they were taking a placebo that had no known health effects at all, and it still worked as good as the uninformed placebo control. I heard this on NPR so it shouldn't be hard to find. I find this to be bizarre and can hardly wait to see how this issue comes out. What if all it has to do with is a little attention from someone who is sympathetic and helps the patient focus on their problem in a less reactive mode? There has been a lot of recent research on the placebo effect and ways to use it in therapy should soon be available. SM

Scilearner. This textbook description is poorly done. To get the principle, imagine a glass of water on the counter. Rotate the glass clockwise and the water stays still. If you had fastened a piece of some bendable plastic sheeting to the inside wall of the glass (artificial cupula), rotating the glass clockwise, with the water staying mostly still, would bend the plastic in the counterclockwise direction. If you continue to rotate the glass, friction will eventually cause the water to also turn clockwise along with the glass so that when you stopped rotating the glass the water would continue to rotate clockwise and bend the plastic in the clockwise direction. One big difference between the glass and a semicircular canal is the amount of friction between the fluids and the container. You would have to turn the glass for a minute or so before the water caught up, while in the semicircular canal it is 10 or 15 seconds. I am not exactly sure regarding this time, but sit in a desk chair that you can spin around in and do the experiment. SM

Gopla, I am not sure what your question is. Alpha helices, beta barrels, and some more exotic transmembrane elements are evolutionarily designed to fit exactly into a membrane. These structures display hydrophobic domains on their exterior so that they can associate with the hydrophobic center of the membrane, and this is what keeps them in place (and how a membrane is made by amphipathic components for that matter). If an alpha helix were too long some portion of the hydrophobic region would be exposed on the outside or inside of the membrane and this would cause problems. Under normal circumstances the genes program for the exact amino acid sequence required to do the job. SM

Steevey, actually Monster92 is correct regarding CO2. Because of the persistent greenhouse effect provided by the CO2 in our atmosphere the earth, without it, would be in a perpetual ice age. SM

Humans have been programmed by their evolutionary past to respond to sensory information both automatically and to learned responses to sensory information. This also includes all the other senses, not just vision and audition, and this evolutionary programming presumably allowed our species to survive. Information processed by sensory brain areas is passed off to multiple other brain systems and if the pattern matches an automatic or learned trigger it causes a response to occur. Your question is a bit vague, and so is this answer, however, much of the high level neural processing beyond sensory (and motor) areas is poorly understood. One interesting recent illustrative finding involves the study of mice that don't have an amygdala (a brain area), bilaterally, that don't show fear behaviors. The researchers found a woman with a rare genetic disease, Urbach-Wiethe disease, in which both the right and left amygdalas are destroyed in middle age. This person was not afraid of anything, not a very dangerous situation that happened to her, not scary movies or animals (she completely lost her earlier fear of snakes and spiders), and not having to talk in front of an audience. In light of previous research, this finding is not a very big surprise. Knowing this bit of information makes it easier to understand how some sensory information (e.g. a large approaching spider) is processed into knowledge of what it is, and then assigned as fearful by the amygdala. SM

Scilearner. Your first diagram shows what you would see in each eye separately. A shows that you would not see at all in your left eye, but would see most of the whole visual field, monocularly, but only with the right eye. B is bitemporal hemianopia in your second post. In this you would only see central vision, but binocularly with the two images fused. C shows that you would only be able to see the left visual field, but binocularly. By the way. The photographs you provide shows the two views of both eyes, not overlapped as they would normally be. You can see them binocularly as they would normally appear, with some depth perception, by crossing your eyes carefully until the two fields lock together into a single field. SM

Ewmon, I live in the US but the only way I can access all the recent journal articles I wish to see is by going to the library. The closest one to me is three hours away. I am emeritus faculty, but my university doesn't even provide access unless I maintain an office on campus. If you have a way to gain access online, please let me know. SM

JohnB: These comments come with apologies to the management because this response has only a marginal relationship to the original post, as are the ones I am responding to. I am really concerned about how attacks on individual scientists are being substituted for well documented scientific discussion. John, I just don’t see where all your anger is coming from. The problem is that the Reuters article just doesn’t support your contentions. You cite a scientist that contradicted what Dr. Trenberth said, but it was a pretty mild statement, and you didn’t note the quotes from Australian scientists that supported his viewpoint in the same article. Here is the version in the Daily Sun: http://www.daily-sun.com/?view=details&type=daily_sun_news&pub_no=97&cat_id=1&menu_id=12&news_type_id=1&news_id=19771&archiev=yes&arch_date=14-01-2011 Keep in mind that these are not statements in a peer reviewed journal, but interviews of experts regarding their opinions about underlying mechanisms of weather. What Dr. Trenberth has said is pretty conservative and obvious. What it amounts to is that it is known that the oceans are warmer, and that weather patterns are known to be affected by warming, so it is likely that any weather event will have a warming component. This is further elaborated in the AMS piece. Some people wish to be more cautious. Big deal. Similarly, I and many thousands of other scientists agree with Trenberth’s AMS piece on science communication that you linked. He pretty much explains what is happening to climate science as the result of concerted disinformation efforts by antiscientific blogs and others who are not actually practicing scientists. The illegal hack of the computers at the University of East Anglia (UEA) Climate Research Unit (CRU) and the Freedom of Information (FOI) requests that he talks about are excellent examples. Here is a little background on the FOI incident. The requests were publicly organized on an anti-science blog. They sent 50 requests over a two day period asking for raw data used in some CRU climate reconstructions that came from meteorological stations in a variety of different countries. These requests were not legally enforceable because the CRU didn’t own the data sets, and they were already available directly from the individual meteorological stations. Here is link to the UK FOI act: http://www.legislation.gov.uk/ukpga/2000/36/contents Look at Part II, 21. Information accessible to applicant by other means. Further the requests were clearly intended to harass the CRU, not to do any science. Only one request was needed, when denied they didn’t appeal, and they didn’t subsequently go to the data sources and get the information. The CRU is a small department and employs only three scientists, and they are required to spend a certain amount of time on each request (I think it is around 12 hours) before making a decision. The scientists clearly, and I think correctly, thought that they were under siege and said things in their private e-mails that are much milder than I would have said about the vandals under these circumstances. This attack was highly disruptive and essentially stopped all research activities for weeks. This type of FOI request is not legally enforceable. See FOI Part I, 14. Vexatious or repeated requests. Regarding the request to destroy documents-- This statement was not made by Dr. Trenberth. He has said that the comment was not appropriate. The comment was lifted out of context from stolen private documents so we don’t know how the conversation actually went. Most important, no documents were actually destroyed. Angry private comments are not illegal, deleting information under request is. See FOI Part VIII, 77. Offence of altering etc. records with intent to prevent disclosure. Not only are such comments not illegal, they are not even very interesting because they are private. If you think they are important, see how many people you know who would be willing to publish all of their private e-mails that discuss a contentious issue. Don't you think it is OK to discuss what you really think with your friends? Have you never heard somebody say something like "I am gonna kill that SOB." Was this illegal or even of interest? There has been no legal action against any of the scientists. There is more information regarding this stupid incident, and the outcomes of the resulting investigations, in the Hasselmann (2010) Nature article referenced in the Trenberth PDF (Communicating Climate Science…) that you linked. Regarding your discussion with Swansont regarding the troublesome tree ring series, I think you are making way too much out of it. This one tree ring series had a divergence problem. This was never hidden, it was reported in detail in the original research article about this series and many times since, and the problem, in turn, has generated a whole new research area. It is interesting that the Spiegel On Line you referenced earlier has an article on recent research of a pine tree series that begins to fill in the divergence. http://www.spiegel.de/wissenschaft/natur/0,1518,661726,00.html But, if you don’t like this series, there are plenty of other tree series that document the hockey stick. But if you don’t like trees, there are plenty of other proxies that document the hockey stick. If you have some peer reviewed scientific information that makes a big difference, please cite a peer reviewed research article that claims to do this. Why not leave out personalities and just stick to the scientific research; this is what is important and completely avoiding the anti-science blogosphere when looking for accurate information would be a good start. SM