Wikipedia:Reference desk/Archives/Science/2009 June 25

= June 25 =

inverse metal
I am trying to start a new article on Inverse metal but I cant seem to find many sources. here is one: http://www.sciencedirect.com/science...21a8092c95ac67 "This material is probably an inverted metal with the deuterons moving in the field from the stationary electrons, which gives a predicted interatomic distance of 2.5 pm, close to the measured value. Thus, we prove that an ultra-dense deuterium material exists."

here is another: http://www2.chem.gu.se/staff/leif_holmlid.html

I was hoping that one of you might actually know about this subject or at least be able to find a good reference for it. just-emery (talk) 01:07, 25 June 2009 (UTC)


 * The article has now been redirected to Ultra-dense deuterium. just-emery (talk) 01:55, 25 June 2009 (UTC)


 * The redirect is now listed for speedy deletion, if anyone's interested. Tempshill (talk) 02:02, 25 June 2009 (UTC)

evolution books
Does anybody have any recommendations on a book covering the topic of evolution that is intended for general readers?


 * The Selfish Gene. Tempshill (talk) 02:03, 25 June 2009 (UTC)
 * On the Origin of Species by Means of Natural Selection, or the Preservation of Favoured Races in the Struggle for Life is supposed to be very good, though I have not read it. Algebraist 02:05, 25 June 2009 (UTC)


 * I agree with Algebraist (and I have read it) - get it straight from the man himself - Charles Darwin's book is remarkably readable. and you can read it online or download it for free. It doesn't cover the role of genetics and DNA because that stuff hadn't been discovered by then.  For specific details on the order that things happened - how and why - with particular emphasis on the path that ultimately leads to humans, I'm fond of reading Richard Dawkin's book "The Ancestor's Tale".  His other famous book on the subject "The Blind Watchmaker" is also very approachable to the layperson. SteveBaker (talk) 02:44, 25 June 2009 (UTC)
 * If you are looking for a basic introduction masked behind a work of fiction I would check out Next by Michael Chrichton(sp?)Drew Smith What I've done 06:36, 25 June 2009 (UTC)
 * Darwin is a good writer, but he is very defensive and thus proceeds at a snail's pace. He also is not yet aware of DNA and the actual mechanisms of inheritance and variation. For a general audience, I would recommend a book that covers the modern synthesis. Dawkins also writes very graceful English. The Blind Watchmaker is more accessible than The Selfish Gene. I also liked The Ancestor's Tale, but it's a very different take on the topic. --Stephan Schulz (talk) 11:07, 25 June 2009 (UTC)
 * I've recently been on a bit of an evolution bender, reading and watching as much as I can find about it. It was Darwin's 200th birthday this year and to mark the occasion BBC made several very good docos, including one presented by Richard Dawkins called The Genius of Charles Darwin and another by David Attenborough called Charles Darwin and the Tree of Life. I think you can pretty much watch both for free entirely on youtube. Also, I have to admit I tried to read on origin of species, but definitely it's a bit of a struggle to read for a "general" reader, the language is dated and I found it very hard to get into a flow, especially since a lot of my reading is on a tram to and from work.. However I found it as an audiobook read by Dawkins and I put it on my ipod and I have to say, it was brilliant and I enjoyed it very much. I watched probably over half a dozen documentaries about evolution before getting the audiobook, but I still got a LOT out of the book. Vespine (talk) 06:21, 26 June 2009 (UTC)
 * You're an evil person and I will be out of US$ 15.47 before this day is over ;-). --Stephan Schulz (talk) 07:40, 26 June 2009 (UTC)

Some other good writers in the area: E. O. Wilson, Stephen Jay Gould, Jonathan Weiner and Matt Ridley. You should be able to sample many of their writing through google books etc, and then can delve into whetever picks your fancy. Abecedare (talk) 08:45, 26 June 2009 (UTC)

gravitational intensity of a moving body
If a body were moving near the speed of light would the intensity of its gravity be greater or less in the forward direction than in the rear direction? -- Taxa  (talk) 05:24, 25 June 2009 (UTC)
 * Neither. The field is symmetric in the forward and reverse directions. -- BenRG (talk) 08:56, 25 June 2009 (UTC)
 * Something to consider though, if you were to go faster than the speed of light wouldn't the gravitational waves have some equivalent of a sonic (gravitonic?) boom? TheFutureAwaits (talk) 17:45, 25 June 2009 (UTC)
 * Nothing can go that fast - so it's a non-question. If you insist on being pig-headed about that and try to plug super-luminal speeds into the lorentz transformations, in an effort to brow-beat the math into submission - you get imaginary numbers in the answers - which is math's way of saying "Give it up already - Einstein was right!".  So there is no meaningful physical answer even in the hypothetical. SteveBaker (talk) 21:04, 25 June 2009 (UTC)
 * Well maybe I will! Nah, you're right just an interesting thought but yeah hard to find the consequences of an impossible circumstance. TheFutureAwaits (talk) 21:20, 25 June 2009 (UTC)
 * Čerenkov radiation is kind of like the electromagnetic version of a sonic boom, but I don't think that has a gravitational equivalent. Unlike electromagnetic waves, gravitational waves travel at c through any medium, as far as I know. -- BenRG (talk) 22:00, 25 June 2009 (UTC)


 * Are you saying that nothing can travel faster than the speed of gravity? -- Taxa  (talk) 03:12, 26 June 2009 (UTC)
 * The speed of gravity is the same of the speed of light, so yes. --Tango (talk) 11:16, 26 June 2009 (UTC)
 * Yes. This is one of the main differences between Einsteinian and Newtonian physics. Light, gravity and indeed even pure "information" all have a speed limit of C. If you had a push rod made of the hardest substance known to man, it could be harder then diamond, doesn't matter, if it reached all the way from the earth to the sun 8 light minutes away, and someone there was holding the other end, when you move the rod the person on the other end wouldn't feel it for 8 minutes. Vespine (talk) 06:04, 26 June 2009 (UTC)
 * Ok. To me, this (good) answer leads to a new question. In your example, would the experienced delay between moving one end of the 8 light minute long rod and sensing the movement 8 minutes later at the other end stem from loose molecular bonding in the material (the distance one molecule has to move before the next molecule moves), the unavoidable inertia of such a rod or are you referring to some other kind of strange limit of the speed of "information" transfer. JimmyVolatile (talk) 13:44, 1 July 2009 (UTC)

matlab how to
okay great scientists sitting over there ...plz any one help me.i am required to show coordinates(x,y) of points in my plot in matlab .how should i get it.

Sameerdubey.sbp (talk)


 * There is a button at the top of the plot window that does exactly that. The button is called "Data Cursor". You click it and then click one of the data points on the plot; the coordinates of the data point then appear in a rectangular box next to the point. To remove, hit Delete key. --Dr Dima (talk) 07:28, 25 June 2009 (UTC)

thanks a lot Dr.dima.Can you suggest me some good book on matlab .if i belong to MECHANICAL ENGINEERING TRADE.


 * I mostly learned Matlab by trial and error, and by using HELP and DOC commands a lot :) . Matlab help files are really good. Matlab debugger is excellent, too; you will find yourself using it a lot once you get to a more advanced stage. A book that I can recommend (though I came across it long after I learned Matlab) is Getting started with Matlab 7 by Rudra Pratap. Hope this helps. --Dr Dima (talk) 21:42, 25 June 2009 (UTC)

how to optimize
which optimisation procedure is used in optimisation of heat transfer problems.i want to optimize one dimensional heat transfer. Sameerdubey.sbp (talk)


 * Please elaborate. Normally, the word "optimization" refers to finding a maximum of a function of one or more variables on a given domain under given constraints. Heat transfer is a phenomenon, not a mathematical function. What is it that you want to optimize? If you want to learn about optimization algorithms in general, you can start with Simulated annealing, gradient descent, and Nelder-Mead method. --Dr Dima (talk) 07:40, 25 June 2009 (UTC)

Gasoline and water
If I soaked a paper towel in water, then got as much gas on it as I could, would the towel burn? I know gas and water don't mix, so I wasn't sure, but I didn't think it would be a good idea to try to find out myself :-) 24.93.116.128 (talk) 14:18, 25 June 2009 (UTC)


 * Depending on the specifics, possibly. The gas vapors could certainly burn.  If there was enough gas, that fire could continue long enough to evaporate the water and then burn the towel.  As a practical matter, though, I expect that there wouldn't be enough gas. &mdash; Lomn 14:36, 25 June 2009 (UTC)


 * Liquid gasoline doesn't burn anyways. In fact, being condensed phases, liquids do not usually burn at all, strictly speaking.  What burns is the vapors above the liquid, due to evaporation.  When those vapors burn, they generate heat, increasing the evaporation of the gasoline and thus feeding more vapors into the flame.  The deal with a gasoline/water mixture is whether or not there is a high enough concentration of gasoline to produce enough fumes to maintain the burning.  When solids burn, like say the paper, the solid will actually burn in the solid phase since heat will remain in one place long enough to raise the temperature to the point where the surface will react with oxygen in the air, and thus support a burning reaction.  In liquids, like gasoline, the fluid nature of the material means that it is almost impossible to get the liquid to maintain local hot spots which are hot enough to both remain in contact with oxygen and support the combustion reaction; at least not significantly so when compared to the vapor combustion happening above the liquid.  --Jayron32. talk . contribs  15:07, 25 June 2009 (UTC)


 * I'm pretty sure it would burn, but nowhere near as fiercely as without the water. 64.42.255.217 (talk) 17:08, 25 June 2009 (UTC)

When ships are hit by bombs or shells or torpedoes and sink, the swimming survivors have often encounters burning oil and gasoline on top of the water. So a layer of gasoline on top of a pool of water should still burn. The towel would not stop it from burning. Edison (talk) 19:10, 25 June 2009 (UTC)
 * See Free Willy 2. Aaadddaaammm (talk) 20:14, 25 June 2009 (UTC)


 * I think the issue will be will the heat from the gasoline layer on top which is burning be enough to ignite the wet paper towel. The paper towel certainly would not stop the gasoline from burning.  65.121.141.34 (talk) 20:14, 25 June 2009 (UTC)


 * The issue is this - the paper can't burn until it reaches its ignition point...that's around 450 degC (Yes, Ray Bradbury screwed up - he should have called his book "Centigrade 451" or "Fahrenheit 844"). But so long as there is still liquid water around - the water will absorb the heat until it boils away as steam at 100 degC.  The gasoline won't mix with the water - and in any case, it's not the liquid gasoline that burns - it's the vapor.   So here is what happens.  Initially the towel is wet, there is a layer of gasoline - the gasoline gives of vapors which burn - thereby heating the gasoline and making more vapor.  Meanwhile, the water is also heating - and will eventually start to boil.  The paper will burn if the water boils away before the gasoline runs out - but not otherwise.  So the answer depends on how much gasoline and how much water are lying around...which is not well-specified in the question. SteveBaker (talk) 21:00, 25 June 2009 (UTC)
 * Dipping one's hand in molten lead is a fairly extreme demo of some of these issues. DMacks (talk) 21:10, 25 June 2009 (UTC)

Body hair and odor - Vestigial?
Why humans have less body hair than other members in family Hominidae? What is the function of body hair other than thermoregulation? Those who artificially removed body hair do not have any problem with thermoregulation. Then how much effect body hairs have on thermoregulation? Google search does not show any scholarly reference. I found this which claims body hair can also play a role in sexual attraction. How is it possible, in fact hair removal is more sexually attractive than having body hair. Finally what is the function of body odor? This claims armpit odor helps in mating. But people use deodorants to get rid of armpit odor and body odor. Should not human body odor and body hair be considered vestigial? Njuot (talk) 14:26, 25 June 2009 (UTC)
 * I'm sure a great many users have a variety of fascinating opinions on this, or even reports of others' opinions, but for me this is a great case where Science Inc. can earn itself rare humility points by shrugging its shoulders and saying "we don't really know". --Dweller (talk) 14:34, 25 June 2009 (UTC)
 * It's worth appending, however, that several of the points above are purely opinion. The presence or absence of body hair or body odor is neither universally advantageous nor disadvantageous.  People vary, and their preferences vary.  Additionally, a statement that "hair is not required for thermoregulation" in no way disproves a statement that "hair aids in thermoregulation".  I think Science Inc. can do a greater service (though at the loss of humility points) by noting that there's very little science in the question. &mdash; Lomn 14:40, 25 June 2009 (UTC)
 * It is a complex question. The one reason for that, that stands out in my mind, is that vestigial is in the final analysis hard to define. Everything has a bearing on some other things. And even body odor and body hair are hard to define. Are we talking about 2 days without a bath body odor, or the more pronounced variety from months without a bath? And is it proper to call body odor a primary aspect of the human body, or is it more properly characterized as a byproduct, which could be altered by evolution, but only in a complex relationship to other biological aspects, such as the thermoregulation that the questioner brings up, and to biological waste removal -- another function of skin secretions including sweat. When we talk about hair -- which hair? Some could indeed probably be considered vestigial. Hair in other places on the body is probably functional in our present species. I think the question is too broad to have a simple answer. Bus stop (talk) 14:54, 25 June 2009 (UTC)

I mean overall body hair except facial hair, head hair, armpit hair and pubic hair. By body odor, I mean naturally occuring odor like armpit odor and odor in public region. Njuot (talk) 15:06, 25 June 2009 (UTC)
 * The fact remains. Your claims that such hair and odor are advantageous or disadvantageous are merely opinion, and your positions are certainly not universal. &mdash; Lomn 15:19, 25 June 2009 (UTC)


 * I think vestigial is a concept. It is abstract. It can be regarded isolated from the rest of the functioning of the organism. But how can one say that body odor is vestigial, except after considering it in a relationship to the complex biological processes that result in body odor? All things cost the organism something, and bring the organism some benefits. I don't think it can be simply answered one way or the other, without a complex examination of the processes that lead to body odor. Would body odor be vestigial if a great cost savings were afforded by releasing wastes through the pores of the skin in this way, despite the fact that we might not smell so good sometimes? Hair is in my estimation a little more straightforward. I don't see hair as being so intertwined with other bodily processes and functioning, but I could be wrong about that. I am just opposed to jumping to hasty conclusions about parts or processes of the human body being classified vestigial. Why not say that flatulence is vestigial? Did body odor ever serve a function that contributed to the species' survival or reproduction? Bus stop (talk) 15:50, 25 June 2009 (UTC)

I don't have time to pour through it right now, but there is actually a good deal of science on the issue. Someguy1221 (talk) 20:18, 25 June 2009 (UTC)

As an explanation of why humans have less body hair than other hominids, I rather like the aquatic ape hypothesis, although I think it's more poorly received by academics than our article might suggest.- gadfium 22:14, 25 June 2009 (UTC)


 * Oh, I don't know; I think the reception section deals with it rather well, though my time in archaeology/anthropology is now more than a decade gone. It's a really neat hypothesis, but it suffers from some rather crippling deficiencies (as outlined in our article). I think it's true that it perhaps hasn't been given an entirely fair shake among professional anthropologists (among whom there is an insane amount of politicking), but supporters resolutely fail to provide any testable forms of the hypothesis, which is the ultimate raison d'etre for any hypothesis - to be tested. Instead, they provide a bunch of very nice points that indicate an aquatic background; that's good enough for laypeople, but it just can't convert a reasonable skeptic. Matt Deres (talk) 00:59, 26 June 2009 (UTC)

Click for Hair. Cuddlyable3 (talk) 23:19, 25 June 2009 (UTC)

Human hair is important during Sexual selection, so it still is getting selective pressure. -- JSBillings  23:42, 25 June 2009 (UTC)


 * It just occurred to me that the original question compares modern humans to other members of the family hominidae (including chimpanzees, gorillas, humans and orangutans). That is an incorrect comparison. I just want to point that out. Concerning vestigiality the proper comparison is to our own ancestors. See article Human vestigiality. Bus stop (talk) 13:21, 26 June 2009 (UTC)


 * Sure, but as we don't have good samples of proto-hominid skin, the next best thing is to assume that traits shared by all-but-one surviving species of the clade are ancestral. —Tamfang (talk) 03:23, 25 July 2009 (UTC)

Dew point in UK
What is the highest recorded dew point in the UK?


 * Well, it's probably the same as the highest air temperature ever recorded because there's always going to be somewhere with 100% humidity...near a waterfall or something. SteveBaker (talk) 20:50, 25 June 2009 (UTC)


 * Whoa! The air at 100% humidity "near a waterfall or something" will be cooled by the evaporating water; it won't be as warm as the nearby air at lower humidity.  --Anonymous, 23:57 UTC, June 25, 2009.


 * OK, what's the highest Dew Point recorded at a weather station?


 * A Google search finds this, reporting a dew point of 23.8° C (about 75° F) in July 1983, but in Shannon, Ireland, which of course is not quite the UK. Looie496 (talk) 01:07, 26 June 2009 (UTC)

Upcoming Malaysian Tsunami
Are there any indications that a tsunami is due to erupt out of the sea sometime in the next few months? Are these things predictable at all? I am hearing chatter in the undergrowth, if that metaphor applies to the sea. Chatter in the kelp? 82.111.24.28 (talk) 14:59, 25 June 2009 (UTC)


 * Sometimes a tsunami can be predicted, but it is on a scale of minutes or hours, not months. 65.121.141.34 (talk) 15:04, 25 June 2009 (UTC)


 * Right. A tsunami can be predicted fairly well once its triggering agent occurs.  Your most common tsunami triggers are volcanoes and earthquakes.  Prediction of volcanic activity, while an inexact science, can at least give some indication of the danger (though it's not going to improve the minutes-to-hours timeframe of a tsunami warning).  Earthquake prediction is even less granular, so you're not going to gain anything except that a given region is at risk generally.  All that said, there are a couple ways that a tsunami could be accurately predicted months or years ahead of time.  A sufficiently large impact event over ocean will likely create tsunamis and there's a very good chance we'll know that said large impactor is coming and when it will hit (though perhaps not precisely where).  A sufficiently large underwater nuclear test could likewise generate a tsunami and the timing will be known in detail to at least a few people. &mdash; Lomn 15:17, 25 June 2009 (UTC)


 * The only "indication" is this email hoax. Jay (talk) 10:21, 26 June 2009 (UTC)

half-filled and full-filled shells
our chemistry teacher just taught us that half-filled and full-filled orbitals are more stable than others, like for ex. p3 is more stable than p4 and likewise, d10 is more stable than d7. can anyone explain WHY?? (if there's a wiki article about this, please tell me) thanx —Preceding unsigned comment added by 122.50.128.194 (talk • contribs)
 * You can start D electron count. --Wirbelwind ヴィルヴェルヴィント (talk) 16:50, 25 June 2009 (UTC)
 * Actually, there is a concept in quantum mechanics known as Angular momentum coupling, more commonly called "spin-spin coupling" or something similar. Basically, electrons which have "matched" spin states are slightly more stable than electrons with "anti-matched" spin states; in other words electrons which are all "spin-up" will "couple" in such a way as to make the system slightly more stable than a situation where some electrons are "spin up" and others are "spin down".  It is a very small effect, but in a few rare cases it is enough to create some non-intuitive electron configurations.  In the classic case of Chromium, the expected electron configuration of "[Ar]4s23d4" has five "up-spin" electrons and one "down-spin" electrons.  The alternate configuration of "[Ar]4s13d5" produces a configuration where all six of these electrons are "up-spin".  That small increase in stability is actually enough to overcome the tiny energy barrier between the 4s and 3d levels, which are almost (but not quite) the same energy.  Since 3d is only VERY SLIGHTLY at a higher energy state than 4s is; the small loss of energy by the spin-spin coupling present in the "[Ar]4s13d5" configuration is enough to overcome the energy difference between the 4s and 3d states, and this configuration, and not the expected one, occurs.  --Jayron32. talk . contribs  01:51, 26 June 2009 (UTC)

Why can slower cars turn in tighter circles?
I'm sure this is an elementary problem. But why does my car have a smaller turning radius when I'm moving slowly as when I'm moving quickly. It's a normal ten year old front wheel drive with power steering (and no four wheel steering). I can understand if I was driving 50mpg with tire slippage on the surface. But when trying to squeeze into a parking space, I'm only going less than 1 mph. --Navstar (talk) 16:53, 25 June 2009 (UTC)
 * How do you know that it has a smaller turning radius when going more slowly? How do you determine this? Bus stop (talk) 16:57, 25 June 2009 (UTC)


 * (ec) What makes you believe this is the case? The only obvious explanation I can think of would be if you were going fast enough and trying to turn tight enough to produce understeer, but it sounds like you're saying that's not happening.  Discounting loss of traction, I'd expect turning radius to be speed-independent. Friday (talk) 16:58, 25 June 2009 (UTC)


 * It's not true - your car can turn just as tightly at any speed...except of course that you risk skidding and rolling over if you actually try to turn that tightly at higher speeds. The radius of turn is determined solely by the angle that the front wheels will turn and the length of the wheel-base (ie the distance between front and rear wheels.  The way to imagine it is if there was a pair of long rods sticking outwards from the centers of your wheels - parallel to the axles.  If the rods are long enough then when you turn the steering, the rod coming out of the front inside wheel will cross the rod coming out of the rear inside wheel.  The point where they cross is the center of the turning circle - because if neither wheel is skidding, they must be moving at a tangent to that circle.  (That's actually an over-simplification because the outside wheels follow a different track and the front wheels aren't actually parallel (see toe in)...but it gets you thinking about what's going on).  None of that geometry changes depending on the speed you're going...so unless the wheels are skidding - your turning circle is independent of your speed. SteveBaker (talk) 20:46, 25 June 2009 (UTC)


 * Four-wheel steering deserves a mention here. There are systems which do reduce your minimum turning radius at low speeds by allowing the car's rear wheels to pivot.  That said, the added cost, weight, and complexity of these systems has limited their adoption; four-wheel steering has only been offered on a few, generally high-end or specialty, vehicles, and the option has often been withdrawn due to lack of popularity.  (See, for example, GM's Quadrasteer system.)
 * Note that this response likely doesn't apply to the original poster's question, however. TenOfAllTrades(talk) 22:59, 25 June 2009 (UTC)


 * Anyone who has while driving in a straight line encountered a sudden crosswind knows this causes the car to deviate its direction. This is the nature of the small patch of flexible rubber in contact with the road, it does not rigidly define the direction of wheel roll regardless of side forces. (This has nothing to do with skidding and the OP surely means mph not mpg.) Perhaps SteveBaker's car has spiked metal wheels. Cuddlyable3 (talk) 23:05, 25 June 2009 (UTC)


 * I suppose you wouldn't be able to turn as sharply since you'll have travelled a greater distance in the time it takes the to turn the steering wheel, but once you've got the wheel in position the speed shouldn't be a factor (other than the caveats mentioned above). --Tango (talk) 23:23, 25 June 2009 (UTC)


 * You might "suppose" that - but you'd be wrong. Find a nice empty parking lot.  Turn the steering wheel on your car until it locks.  Drive slowly in a circle...gradually increase the speed and you'll see that the diameter of the circle doesn't change until your tyres are squealing.  Don't take my word for it - do the experiment. SteveBaker (talk) 03:02, 26 June 2009 (UTC)
 * Have you actually done this experiment? Rubber tires can "walk" without actually slipping. This is very obvious with studded wheels, as on most mountain bikes, but the principle applies to all flexible tires. A new stud will initially be perpendicular to the surface of the tire. As soon as it comes into contact with the road and starts bearing load, it will bend sideways in reaction to the sideway force it transmits to the bike, and hence give way. As it is unloaded, it returns to its original position. Thus, each successive stud will result in some sideways "not-slippage". For unstudded tires, apply the No cat Theorem. --Stephan Schulz (talk) 07:58, 26 June 2009 (UTC)
 * Do you want to check whether that No cat Theorem link works? Cuddlyable3 (talk) 10:43, 27 June 2009 (UTC)
 * Well OF COURSE I've done the experiment! I'd hardly tell someone to do it if I hadn't!  When I was into autocross driving, I bought an accelerometer for my car to allow me evaluate the cornering force for different tyre and suspension setups.  In the course of experimenting with that - I needed to be sure that the radius and speed of the turn was known so that I could calibrate the accelerometer (it's not as simple as it sounds because it depends on where within the car you mount the thing - and because of things like the toe-in of the steering, different parts of the car are going around in different circles).  So I did this driving in circles thing in a disused parking lot using the parking space markings and a video camera on a tripod to see where the wheels went.  I even did it on concrete and tarmac to see if there was a difference.  At speeds below where the tyres lose grip (which at maximum lock is surprisingly slowly) - the radius of the turn remains the same at 1mph as it is at around 20mph - at least to within inches (which was about what my experimental error was).  If the effect Stephan is talking about is real - it's also negligable. SteveBaker (talk) 15:21, 26 June 2009 (UTC)


 * You misunderstand me (perhaps because there is a typo in my response! now fixed). I'm talking about turning the wheel while moving. If you are going in a straight line at 10mph and try to turn 90 degrees while maintaining that speed you will be able to do so in less space than if you tried the same thing at 30mph. --Tango (talk) 11:13, 26 June 2009 (UTC)


 * Right, this could account for it seeming like a larger turning radius, even when it's not strictly speaking true. And the faster you attempt to turn the wheel, the more likely you are to induce understeer.  I don't see this question as very practical- how often do you really turn the wheel all the way while going faster than a crawl?  Friday (talk) 14:39, 26 June 2009 (UTC)


 * Certainly when tyres slip - which is likely if you jerk the steering with high momentum - then the turning radius is going to change...it might get larger (understeer) or perhaps smaller (oversteer). All bets are off once you're losing grip.  But even then, our OP may be wrong - if your car oversteers - then there is a possibility of turning tighter at higher speeds because the back wheels are slipping outwards and the front are not.  The fastest way to turn my car is a 'handbrake turn' when the car can be made to do a 180 degree U turn within a tiny amount of space!  (Although this is generally under-rated as a driving technique because of the alarm it engenders in bystanders! :-) SteveBaker (talk) 15:21, 26 June 2009 (UTC)


 * It's a poor answer to tell the OP that what they observe doesn't exist because it shouldn't exist. At least SteveBaker is constructive about the value of an OR experiment. Here is an experiment for SteveBaker. Sit in your car at rest. Can you swing the steering wheel a little (no steering lock engaged) ? I think you can, and that is because your rubber tyres have flexible rubber walls. Those walls are capable of twisting above the area of tread in contact with the road. That results in the car moving in a different direction to the angle at which the front wheels are rolling. Please don't insist that the dynamic behaviour of a car at speed is exactly predicted by its static Euclidean geometry. Cuddlyable3 (talk) 10:43, 27 June 2009 (UTC)
 * I'm not denying that tyre walls flex (but not by much!) - but I am strongly denying that it has much effect on the radius of the turn when they aren't slipping. Sidewall flex alters the amount of side-force you can apply without them slipping - but until they slip the diameter of the turn is totally independent of speed.  This is more than just a casual remark - I've studied this quite carefully in my efforts to be a better autocross competitor. SteveBaker (talk) 01:33, 29 June 2009 (UTC)

How to produce protein homology schematics as seen in scientific journals?
How are diagrams like this produced? Does one have to manually fashion this in an image editing suite or are there specially-designed tools available on the internet? --94.212.39.7 (talk) 17:03, 25 June 2009 (UTC)
 * FWIW, the image comment says "Created with GIMP", and GIMP will not remove a pre-existing comment if some other software has put one in. It's suggestive that they just created it in GIMP, but not definitive.  --Sean 20:09, 25 June 2009 (UTC)
 * You can make a figure like that in a few minutes using the drawing tools in PowerPoint, or if you want a really publication-quality image go for Adobe Illustrator or something along those lines. The hard part is deducing the domain structures of the proteins you're trying to depict.  But that's a different question. --- Medical geneticist (talk) 00:15, 26 June 2009 (UTC)


 * MyHits database seems good at locating domains but then one has to manually construct the schematic which would be a lot of work if you wanted it to scale (the above example is not to scale). I was hoping that some such database had an automatic schematic output. --94.212.39.7 (talk) 08:40, 26 June 2009 (UTC)
 * Start by seeing what tools the author of such diagrams cites in the journal article. Some software requires that it be cited in publications that use it. DMacks (talk) 21:04, 27 June 2009 (UTC)

How does the compass in the iPhone work?
Just curious. It seems to work the same if the phone is held upright or flat, unlike a regular camping compass. Is there some microscopic bead floating in fluid? --70.167.58.6 (talk) 17:06, 25 June 2009 (UTC)


 * I suspect it is a GPS receiver and not a magnetic compass of any sort. If you are not afraid to do so, you can try to move a weak magnet around your iPhone and see what happens. Magnetic compass will react, GPS will not. I do not own an iPhone so I cannot test this. --Dr Dima (talk) 17:54, 25 June 2009 (UTC)
 * Also, GPS will likely cease to function in an elevator or in any space with poor or no reception of the radio signal; however, metal walls can not block a constant magnetic field. Therefore, magnetic compass in an elevator will still point in a definite direction (either to the North or to the nearest permanent magnet). --Dr Dima (talk) 18:05, 25 June 2009 (UTC)
 * From here, "See which way you’re facing.
 * The new iPhone 3GS does in fact have a built-in Magnetometer as well as a GPS. I think the OP is asking how the magnetometer in the iPhone 3GS works.  --Zerozal (talk) 20:35, 25 June 2009 (UTC)

A built-in digital compass rotates maps to always match the direction you’re facing. You can also use the compass on its own.1". Not very useful, but the footnote says "Compass reliability may be affected by usage conditions such as nearby magnetic fields". Do you have to calibrate the compass or anything? I have an old cellphone that I have to rotate 360degrees and then it works. Aaadddaaammm (talk) 20:10, 25 June 2009 (UTC)


 * I believe that is a true magnetic compass, similar to what is used in the G1. Dragons flight (talk) 20:14, 25 June 2009 (UTC)


 * It must be a real digital compass - GPS doesn't get you direction - only position. GPS units that have a direction indication (eg in a car sat-nav system) work by detecting the direction you're moving - not the direction you're facing.  Digital compasses are pretty cheap devices now - there are chips with three-axis compasses so you can have the thing work in any orientation. SteveBaker (talk) 20:38, 25 June 2009 (UTC)


 * Yeah, you're right. GPS can determine the direction you are moving, but not the direction you are facing. So there must be a magnetometer in there... Nice! --Dr Dima (talk) 22:49, 25 June 2009 (UTC)


 * I'm wondering whether or not putting the phone in the microwave would be an effective way to test whether it was magnetic or not. From my understanding microwaves are similar to a Faraday cage (I don't mean turn on the microwave). Would the Faraday cage prevent it from receiving cell phone signal? (I know it can block radio)


 * Our page is rather poor on this subject, but the relevant link is Compass. --Polysylabic Pseudonym (talk) 01:37, 26 June 2009 (UTC)
 * And a bit more - the iPhone most likely uses a 3-axis hall effect magnetometer. In other words it will use an integrated circuit with three hall effect magnetic sensors, one pointing up/down, one pointing left/right, one pointing front/back. Based on the strength of the local magentic field in those three directions the device can work out which way is magnetic north. --Polysylabic Pseudonym (talk) 01:46, 26 June 2009 (UTC)

"From my understanding microwaves are similar to a Faraday cage (I don't mean turn on the microwave). Would the Faraday cage prevent it from receiving cell phone signal?" -- The microwave oven is designed to block any radio waves with a frequency up to and including the millimeter-wave rays used for microwaving the food (that's to keep you from microwaving yourself and everyone else in the kitchen), so it will block any radio signal in the cell phone band (which has a frequency at least 100 times lower). 76.21.37.87 (talk) 06:41, 26 June 2009 (UTC)


 * does the iphone read magnetic north, or true north? 65.121.141.34 (talk) 13:16, 26 June 2009 (UTC)
 * The sensors must be returning magnetic north - but if you have GPS and some means to know how the magnetic pole is drifting (the iPhone has the Internet - so it does) - then you can easily convert magnetic north to true north in software. Whether it actually does that is anyone's guess.  I'd hope that whatever compass "app" was being used would have a menu option to switch between the two...but I have no idea whether the authors were really that smart. SteveBaker (talk) 14:44, 26 June 2009 (UTC)
 * Can anybody who has an iPhone do an experiment? Get an ordinary magnetic compass and see whether it points in the same direction as the iPhone's compass.  I'm curious about 65.121.141.34's question myself.  --Bowlhover (talk) 22:30, 29 June 2009 (UTC)

Why do some globe willow trees have what appear to be blossoms?
We recently moved into a new home and planted six new globe willow starts. All seem to have taken root and are doing well, but only one of them has what appears to be blossoms. It's totally loaded with them! Can you help me to understand if this tree is really blooming, and why it only happened with the one tree? Thank you 505LilaC505LilaC (talk) 17:15, 25 June 2009 (UTC)


 * A photo and your country of location would be helpful.86.4.190.83 (talk) 18:06, 25 June 2009 (UTC)


 * Globe willow, Salix matsudana, is dioecious, and so are its hybrids. So, there are "male" trees and "female" trees. I guess it is possible that in the particular cultivar you have the male and female trees start blooming at a different age, or that one of the genders is sterile and produces no flowers at all. I do not know the genetics of willows, but in general there is a Haldane's rule for hybrid sterility. --Dr Dima (talk) 18:18, 25 June 2009 (UTC)

Grow Your Own
Would it be possible for a man living in a 920 sq ft apartment in New York City to grow all his own food year round? Assuming the apartment rarely gets direct sunlight but you could use hydroponics, artificial lights and whatever chemicals is this actually feasible? (My friend Marcus actually wants to do this and asked me if it was possible but I don't know where to begin...) TheFutureAwaits (talk) 17:41, 25 June 2009 (UTC)
 * Even if you could, you would need to buy in lots of energy, fertiliser, etc. so if the intention is to be self-sustaining, this wouldn't count. Do they have allotments in NYC? That would be a better way to do it. If the intention is just to do if for the sake of it, it could be pretty almost possible - there would be some things you would need to buy to get a balanced diet (you would need some salt, for example). The internet is full of advice on this kind of thing, just Google it. (I did and found this site, which looks fairly good.) --Tango (talk) 17:56, 25 June 2009 (UTC)


 * Looking at it from a purely calorie point of view, assume that an average corn yield is 100 bu/acre. That is 2,535 kg of corn.  1 kg of corn has 900 kCal.  The apartment is .021 acres.  Assuming 2,000 kCal a day to live, you need to grow 730,000 kCal, or 811 kg of corn.  That is 16x higher yields then a midwest US farm gets (using 100% of space for corn mind you), so I would say that this idea is very unlikely to work.  65.121.141.34 (talk) 18:09, 25 June 2009 (UTC)


 * Well I'm not sure corn would be the best choice (big plant and only a small amount is actual eaten). I think the key requirement would be fast growing, high density and almost entirely edible. Maybe tomatoes or carrots? Are there other veggies that would meet these requirements faster? I assume Marcus could grow some beans, fruit etc on the side to get his vitamin requirements but for the daily calories he would probably focus on one crop.

Oh and he also mentioned lining the walls with shelves and basically stacking shelves and lights wherever he could so I think that would dramatically increase the amount of space available.TheFutureAwaits (talk) 18:33, 25 June 2009 (UTC)


 * I'm not sure something like carrots would be a good source of calories. You need a high carbohydrate food. If cereals aren't a good option (and you are probably right there), how about potatoes? Hydroponics does usually make more efficient use of space by staking, so I wouldn't rule it out just yet. It would be easier, however, to buy a sack of rice, or something, and just grow all the other food he needs himself. Still a very satisfying project, but for more achievable. --Tango (talk) 18:42, 25 June 2009 (UTC)


 * Assuming the friend is only planning to grow his vegetable needs,and will be buying meat, oil, sugar etc commercially, it can be done. Intensively farmed, an open garden about 600 sq.ft. will provide for a family of four for about 8 months of the year, ie excluding mid winter. Indoors with controlled temperature and light, 150 sq.ft might provide for one all year round, with small successive plantings, but some fruit would have to be bought in.
 * Root vegetables are not suited to hydroponic growing, so potatoes, carrots, onions etc would need be grown in tubs or barrels. But these are low-growing, so could have several banks of hydroponic plants above them, eg tomatoes, salad greens and brassicas. Tall plants like corn and beans could not be layered.
 * There would not be much space for fruit trees, but one dwarf tri-graft citrus (lemon, orange and grapefruit perhaps) would fit in a tub and be decorative enough to be kept in a living area, away from the "farm". Strawberries, pineapples and melons could be grown. (WP:OR: I have these and salad vegetables on a 3 ft.x 8 ft. balcony).
 * With good design and plant rotation, the 150 sq.ft. could be reduced to a floor space of about 90, using commercial pallet racking to stack the growing areas 2 or 3 high. Grow lights are very expensive, but, appropriately mounted, a small number could be rotated between the stacks. Ventilation is also important.
 * Even so, the additional electricity usage might attract the attention of authorities on the lookout for illegal indoor plants. Pity about the poor sunlight, otherwise he could generate some solar power.- KoolerStill (talk) 18:44, 25 June 2009 (UTC)
 * Wouldn't solar powered grow lights be rather pointless? Just put the plants in the sun... --Tango (talk) 18:48, 25 June 2009 (UTC)
 * He might have ONE window or outside wall that gets enough sun for a solar panel; that still won't get in to the back walls and between 3 layers of deep shelving.Grow lights can be rotated to run 24/7. - KoolerStill (talk) 18:51, 25 June 2009 (UTC)
 * You can't generate more light using solar power than you receive from the sun (and will, in fact, generate less due to inefficiencies). You can use mirrors to move the light around, if you like, but you can't make more of it without some other source of energy. --Tango (talk) 18:55, 25 June 2009 (UTC)
 * LED growlights (in theory) only emit light on the precise frequencies that photosynthysis is most efficient at. So it's not inconceivable that you could wind up with a net gain. But I still doubt it's possible in the real world with solar panels that you could actually buy.
 * Or you could use a subtractive technique. Certain frequencies of green contribute almost nothing to photosynthesis if you could somehow divert those colors onto a solar panel while leaving the others un-touched to be directly absorbed by your plants you could theoretically get a gain there too. (And that's only the visible spectrum.) I still doubt it would be practical, but the concept can't be dismissed entirely. APL (talk) 00:33, 26 June 2009 (UTC)
 * Yes, I suppose theoretically there is some gain to be had, but the efficiency will never to high enough to take advantage of it with current affordable technology. You can pretty much ignore the non-visible part of the spectrum - for reasons that are not at all coincidental, the sun emits most of its light in the visible part (I don't have the exact figures, but I think it is a sizeable majority). --Tango (talk) 03:10, 26 June 2009 (UTC)

Very cool! This is starting to sound doable! Only thing is the idea is for him to be totally independent of outside food (so no meat, sugar, vegetable oil, etc). Is that a game changer? TheFutureAwaits (talk) 18:57, 25 June 2009 (UTC)


 * A serious amount of food could be grown in 920 sq ft if the ground rules allowed unlimited electricity for lighting and for the considerable ventilation needed to remove the excess heat produced by the lights, to supply sufficient carbon dioxide, and to regulate the humidity. Regular grow lights only produce a tiny fraction of the light the sun supplies. Take a look at proposals for a greenhouse as part of a long duration space voyage. Racks/shelves could be used to allow several levels of planting. Hydroponics are good at producing lush greens like lettice.  There is a bit of confusion evident in the question and comments in not understanding what food groups are necessary to a healthy diet and what fruits or veg supply them. One solar power would not produce enough electricity to do much grow-lighting. A greenhouse with sun exposure is a more reasonable approach, like the experiment with people living in a sealed greenhouse in the Western U.S. Otherwise plan on a huge electric bill, probably more cost than buying fruits and vegetables at the store or a farmers' market. Remember that seeds and fertilizer cost money. Beans supply protein, though incomplete. Sweet potatoes supply sugar, starch and vitamins. Spinach supplies iron. I suppose oil could be pressed from peanuts, olives or corn. Edison (talk) 19:08, 25 June 2009 (UTC)
 * Sugar he can go without, salt he must have. To go vegetarian, he'd need more carbohydrates (I only allowed him some potatoes and corn, not enough to use as flour) and a lot more protein, which would be in the form of soya (not enough floor space) or nuts (no room for large trees). There's no room for wheat or rice. And no room for enough of any feasible source of oil.
 * If he's not averse to killing pets, he could keep chickens: he'd have eggs and meat. Rabbits maybe. (Until he's evicted for it).These would live well on vegetable leaves and some bought grain (or leftovers of last year's corn). A goat for milk. There are noise, hygiene and odour issues with keeping livestock, as well as probably a whole raft of laws and regulations.
 * On a suburban lot, apart from the regulations issue, he'd be able to do it, even on a family scale. Being able to have full-size trees would help with fruit and (olive) oil, climate permitting. - KoolerStill (talk) 19:29, 25 June 2009 (UTC)
 * Animals are a very inefficient food source, I would advise against them. You'll do better just eating whatever you would be giving them to eat. --Tango (talk) 20:01, 25 June 2009 (UTC)
 * Chicken feed will not be nutritionally correct for a human over the long term. APL (talk) 00:41, 26 June 2009 (UTC)
 * Well, no, but you could use the money you are spending on chicken feed to buy human feed. There was never a suggestion to eat entirely chickens, anyway, so you wouldn't be eating entirely chicken feed. --Tango (talk) 03:10, 26 June 2009 (UTC)
 * Spinach has no more iron in it than other dark green leafy vegetables. Someone put the decimal point in the wrong place in the original study that showed high levels of iron in spinach. (See Spinach.) --Tango (talk) 20:01, 25 June 2009 (UTC)

So if I've got this right he'll need stacks of hydroponics for potatos and a mix of some fruits and protein sources along with the occasional larger crops for essential vitamins. Is it true he would get in trouble for having a high electricity bill because they would assume he's growing weed? I mean he does have some (not a ton of) hydroponics equipment already for a reason... TheFutureAwaits (talk) 19:49, 25 June 2009 (UTC)
 * If someone questions the electricity bill all he would have to do is show the police round and let them see that he isn't growing anything illegal. That's not a serious problem. --Tango (talk) 20:01, 25 June 2009 (UTC)


 * If he can afford a 920 sqft apartment in NY, I would assume the electric bill is not a huge concern? Would having plant density that high cause air problems?  Like not enough CO2 for the plants?  65.121.141.34 (talk) 20:12, 25 June 2009 (UTC)

Well he's not loaded but he is kind of an artsy type who would do this for the (hopefully) resulting media attention. Also into the green revolution, vegetarianism, all that stuff... TheFutureAwaits (talk) 20:21, 25 June 2009 (UTC)


 * (ec) It would be easier to grow the illegal and spend the proceeds at the local markets. I disagree about animals being inefficient. The ones I've chosen don't take much space and they don't graze. All would survive on leaves and stalks, which there would be plenty of as byproducts. In fact disposing of them would be a problem. (Though a pig would also live nicely on this diet, and solve the fat problem as well). The rabbits and pig for meat. The chickens are just for eggs, and the goat for milk. A pint of milk has about 20 grams of protein, about half the daily requirement, which would take over 1 lb of beans (green or dried) to equal. The space to grow this amount, day in day out, is not available (it takes an acre to grow 500lbs shelled weight of lima beans). The one goat, eating byproducts, will produce a fresh pint (and more) every day. Eggs are around 6 grams each. Both eggs and milk are useful in cooking and baking, too.


 * Ooops if he's vegetarian he can omit the pig and rabbits. The eggs and milk he'd still need, as he hasn't enough room to grow enough high-protein foods. The larger animals would have provided some CO2, but that can be artificially produced, or piped up from the parking garage. - KoolerStill (talk) 20:40, 25 June 2009 (UTC)
 * I agree with Tango that animals would be too inefficient. The idea here is to be as self-sufficient as possible, food-wise.  Inedible leaves and stalks would normally be composed, and used as fertilizer.  If you fed that to a goat, you’d be turning what would be compost into mainly goat manure.  Besides, the landlord of that NYC apartment is much more likely to be tolerant of a lot of plants growing in the apartment, than keeping a goat in the apartment.  And at least in the suburb of NYC where I live, you aren’t allowed to keep large livestock like a goat even on private property, unless you own at least three acres and can hence qualify as a farm.


 * It would be more likely possible to get away with keeping a chicken in an apartment than a goat, but what would he feed the chicken? If he buys grain to feed the chicken, that defeats the whole self-sufficiency idea.  And if he grows grain to feed the chicken, it would be much more efficient to just eat the grain directly, instead of turning most of the grain into chicken manure.  Red Act (talk) 22:15, 25 June 2009 (UTC)
 * He has to buy in fertiliser and seed to start with. He can get grain for the chicken. Next year there'll be corn cobs that are not up to human consumption. Chickens also benefit from some greens in their diet. Chicken manure is excellent fertiliser, you can't go with compost only. Meanwhile he is also getting EGGS which are a valuable protein food. From the goat (I did mention possible legal problems) he's getting MILK, which is going to be his major source of complete protein, because he doesn't have a spare acre to grow the equivalent in beans. Actually compost and fertiliser would be useful only for the root vegetables, corn and beans etc. Half the produce would have to be hydroponic, if for nothing else than space and weight reasons, which requires balanced nutrients he's have to buy ready made, as there is no soil involved, composted or not.
 * Self-sufficiency notwithstanding, he'd also have to invest heavily in plastic sheeting and strong metal shelving racks, as well as the lights and ventilation system. Being self-sufficient in the open air on terra firma is a lot easier.- KoolerStill (talk) 22:47, 25 June 2009 (UTC)


 * This is nuts - there is absolutely no way for 0.02 of an acre under artificial light to feed a person. That's assuming you use every square foot - subtract living space - realise that you can't load the floor with a foot or more of moist dirt over it's entire area without the place collapsing...there are SO many reasons why it won't remotely work.  I strongly recommend this person reads "Five Acres and Independence" Di Maurice Grenville Kains.  Bearing in mind that Kains is talking about someone who has 250 times as much land as we're talking about here...and with bright sunlight, natural drainage, etc...and the book explains how it's only just barely possible. SteveBaker (talk) 02:54, 26 June 2009 (UTC)
 * Hydroponics can be far more efficient that regular agriculture (that's why it exists!). I'm still doubtful it could be efficient enough, especially at any reasonable cost. As I suggested above - if he buys a sack of rice every so often, he stands a fighting chance and it would still be an impressive achievement. --Tango (talk) 03:10, 26 June 2009 (UTC)
 * "Five acres and independence" was written in 1935. He lived in the country, not in a NYC apartment, and the book is completely irrelevant to this discussion. Modern technology was unknown to the author. Edison (talk) 05:42, 26 June 2009 (UTC)


 * Has the technology of the last 75 years improved food production methods by 25,000%? Otherwise I don't think this would work at all.  A better idea might be to grow a lot of herbs, which can be sold fresh for relatively high prices and use that $ to buy your food.  NYC apartments just are not suitable for subsistence agriculture.  65.121.141.34 (talk) 13:14, 26 June 2009 (UTC)
 * Up to the 1960s, many families DID manage to grow most of their needs (including eggs) on half-acre suburban lots. The difficulty indoors is the soil weight, and lack of air and light. Also the refusal to buy in even oil, salt and flour causes problems. But 900 sq.ft. is nominally enough for all but field crops.


 * Based on RDI Marcus will need daily 50g of protein, 20g fat, 25g fibre and 300g carbohydrate. Carbs and fibre are easy to get from vegetables. Protein and fat are not.
 * PROTEIN: We can't look at the grain/meat conversion efficiency of animals. We need to look at space/protein efficiency. One 20 sq.ft. area will hold one goat, which will convert waste vegetable products into daily 2 litres of milk, providing 40 to 50g of protein and some fat. The only vegetable source for complete proteins is soya, containing 36g per 100g of beans. As other vegetables also contain proteins, let's say Marcus needs 100g of soya daily. A fast-growing cultivar takes 90 days seed to harvest, so he could grow 4 crops a year on the same floor area. He needs about 10 kg per crop. At an average yield of 1280 kg per hectare he needs 800 sq.ft. for the same protein the one goat will give him in 20 sq.ft. Peanuts would take a similar area for a similar yield. Corn yields 2lbs about 6-8 cobs for 10 sq.ft.
 * CARBS - 3 crops of potatoes will give 150lbs from 200 sq.ft. This is 3 medium potatoes a day (some dried for flour to make bread), and the major source of carbohydrates, as there is clearly no space to grow field crops of grains.
 * Root vegetables and field crops need soil. 400 sq.ft. could be divided between potatoes, corn, soya, peanuts, carrots/parsnips, sweet potatoes etc, and even a row of sugar beet. At 2.5 ft depth this is about 90,000 lbs (45 tons) wet soil weight (1.56 ins/sq.in.). (It would be good if it's a fairly modern apartment with concrete slab floors).
 * ABOVE these crops can be hydroponic trays (coming to another 60 tons in water weight) to grow cabbages, vine crops (cucumbers, pumpkins, melons), bush crops (tomatoes, bell peppers) leaf greens and herbs.
 * Vine, bush and cane fruits could be grown (grapes, strawberries, other berries, melons) and 100 sq.ft. given over to espaliered dwarf fruit trees.
 * UNLIKE in a self-sustaining outdoor environment, compost and manure would not be of much use. The necessity to grow 4 crops out of season, the shallow soil depth, and use of hydroponics, mean all nutrients would need to be provided in specific measured quantities, ie artificially produced and mixed. Cultivar selection and very detailed knowledge of requirements would be crucial to the success of the project, which would be a full-time job. Additionally, glut crops would have to be frozen, dried or otherwise processed.
 * The total amount of electricity needed, whether bought or locally produced, makes a joke of "green" sustainability, except perhaps on the space station.- KoolerStill (talk) 13:46, 26 June 2009 (UTC)
 * Would you really be able to feed a goat purely on scraps? And I don't count perfectly edible food that you just chose not to eat before you were too lazy to prepare it carefully or didn't finish your dinner as scraps. --Tango (talk) 15:26, 26 June 2009 (UTC)
 * Twenty square feet per goat? That is downright unethical.  Even a "factory farm" does not restrain a goat to such a small area.  According to this, 4' x 5' pens are suitable if there is an additional area for the goat to exercise in.  According to this more reliable University of California (Davis) Meat Goat publication, one goat needs one acre of pasture.  Raising a goat in a 920-square-foot apartment is not only unethical, it is also unhygienic for you and the goat; it is impractical, probably violates local livestock and agriculture codes, and the presumption that the goat can "eat the scraps" of your hydroponic operation belies a poor understanding of the nutritional requirements necessary for an agricultural goat.  Dairy goats will have a huge requirement for water as well - do you plan to pull this through a municipal pipeline?  Livestock is just out of the question in such a space; chickens are at least moderately plausible, but again, hygiene and health are a major concern (without even bringing up the ethical and legal issues).  If you want to be "independently sustainable," a small apartment in an urban setting (especially with a climate like New York City) is not the appropriate place to experiment.  A better location, with cheaper land, more sunlight, and better growing seasons, would be much more productive.  It sounds like this entire operation misunderstands the idea of agriculture, urbanization, and specialization of labor - there is no way that "urban agriculture" can compete with large scale farming in terms of efficiency and productivity.  The environmental costs, if every New Yorker were to do this, would be downright catastrophic - because so much extra energy and water will be required for each miniature, inefficient farm/apartment.  Nimur (talk) 15:58, 26 June 2009 (UTC)
 * I agree KoolerStill's analysis might maybe work - except for the goat. There is no way you're going to have enough 'scraps' (Which are low-nutritional value by definition - and low in quantity) simply because you're deliberately picking crops that have a high edible-to-waste ratio.  You can't get all of those extra nutrients "for free".  When you subtract the goat's contribution - you're back to starving to death in short order.  This is just silly.  There is no way this is going to work.  It's a clever idea for a TV series or a book - but only if it stands a hope in hell of working.  Since it doesn't, all you're going to do is spend a hell of a lot of money on lights and sprinklers - trash a perfectly good apartment and end up sneaking out to McDonalds after the first crop runs out and you have 3 months to wait until you can eat again. SteveBaker (talk) 18:41, 26 June 2009 (UTC)

Okay, discussed this with Marcus, we're not thinking the goat is a realistic idea and would probably garner some negative publicity (which is counterproductive to the aims of the project). Isn't there some method where he could grow protein and fat? We did discuss possibly walking the goat around the city (it wouldn't be a direct violation of the rules if the goat didn't eat any outside food). Though the idea of Marcus taking a goat on the subway cracks me up... TheFutureAwaits (talk) 16:43, 26 June 2009 (UTC)
 * People are over-emphasising the need for a complete protein from a single source. Getting all the essential amino acids is simple when eating a combination of vegtable foods. eg. Peanuts and wheat together offer all the amino acids needed. So you just need to find a combination of plants that can easily be grown indoors that have complementary amino acid profiles. See Protein combining (and note that the controversy is about eating complementary foods in the same meal - no one suggests that plants cannot provide all needed protein)YobMod 18:29, 26 June 2009 (UTC)
 * Yeah, the protein quality of individual foods should not be a significant concern, particularly assuming that some legumes of some kind will be involved in the diet. For example, it’s not that big of a deal that legumes in general have a PDCAAS value of 0.69 instead of the 1.0 that milk would have, even if the other foods eaten weren’t balancing out the amino acid ratios.  All the lower PDCAAS value means is that you’d need to eat about 45% more protein from legumes than from milk to get the same amount of usable protein, if it weren’t for the effect of other foods balancing out the amino acid ratios.


 * Protein quantity should also not be a significant concern. Protein has 4 calories per gram.  So on a 2000-calorie diet, the RDI’s 50g of protein amounts to getting 10% of your calories from protein.  It’s impossible to get less than 10% of your calories from protein, as long as at least 10% of the calories in every food you eat comes from protein.  And with the exception of fruits, practically all whole plant foods have at least 10% of their calories in the form of protein.  For example, potatoes have about 11% of their calories in the form of protein.  And legumes, of course, have a lot more protein than that, like around 25% for most legumes, and 33% for soybeans.  So as long as you eat a modest amount of some kind of legumes every day and don’t overdo the fruit or junk food, neither protein quantity or quality should be any concern, without needing to give any thought to how the amino acids in various foods will be complementing each other.  Red Act (talk) 20:39, 26 June 2009 (UTC)


 * I am mostly curious as to how they are going to prevent the floor from collapsing, or how the person who is attempting this will keep from going mad living in a place with no room for sleeping, cooking, or bathing, as well as spending hours a day watering and harvesting their plants. Aren't there better things to do in NY?  65.121.141.34 (talk) 19:19, 26 June 2009 (UTC)


 * Well it's going to be almost entirely a hydroponics setup (maybe a few potted plants). So it's not like the floor will be covered a foot deep in wet soil; weight shouldn't be an issue. Regarding sleeping and eating a hammock came up as an idea and he probably wouldn't cook much just to digest as much nutrients as possible. Bathing he can do in the shared bathroom and after living in NY for a few years you learn to be creative. TheFutureAwaits (talk) 19:35, 26 June 2009 (UTC)


 * As a metacomment, I am very proud of the answers people have contributed in this thread. They have been thoughtful and informative. A goat does not need an acre if she is provided feed. A chicken could be in a cage like a factory farm. Imagine it is a greenhouse on a long duration space flight. How much food could come from 920 sq feet by about 8 feet high? It is not a midwestern farm by any means. Rabbits could live in a screen wire hutch, their droppings could feed worms which are fed to tilapia and the effluent from the fishpond could water and fertilize the crops which feed the rabbits and people. This was put into practice decades ago. The humans eat vegetables, fish and rabbits. A dairy goat would be an expensive treat. Hydroponics rule: the dirt is just along for the ride. Edison (talk) 03:03, 27 June 2009 (UTC)


 * Well, I thought the nanny could wander around in the hydroponics corridors, too, not be tethered in that tiny space 24/7. Ditto the chickens could "free range" among the soya and corn. The poorer ears of corn would go to the animals. Tango, by "scraps" I don't mean table scraps, but the stalks and leaves we don't eat, but they do contain nutrition and animals like them. (Did you know about 15% of the cabbage you buy has been discarded as inedible outer leaves?). A goat will NOT drink more than a bathtub of water a day, which the municipal system has no trouble delivering.


 * TheFutureWaits said hydroponics won't be too big a weight. Well, sorry, they'd have to be at least 6 ins. deep and water has weight, too. It would be about the same as the soil. And root crops won't grow in water, yet they generally contain more protein and energy (potatoes, sweet potatoes, yams, sugar beets etc). Potatoes are THE staple carb in Central Europe. But to get enough protein from them, Marcus would have to eat 4 lbs a day (about 20 medium spuds) (and taking the whole 900 sq.ft to grow) and the quantities are equally unlikely from other low-protein sources.
 * Vegetarians often get much of their protein from nuts (a compact source, 4 to 6 g in an ounce) but nut trees are large and take 10 to 15 years to start producing. Tofu and other soya products are also a major source, but I've shown growing enough soya would take 800 sq.ft. Deciding to vary the sources does not undo this number...whatever you reduce, something else equally space-hungry will have to replace. Much of Mexico subsists well on beans and corn, which do provide a good balance of the essential proteins, but both these do take space to grow.


 * This diet will be woefully inadequate in fats, without animal products, because there is no space to grow oil seed crops. An established large olive tree can produce 500 lbs of olives; a small espaliered one might be lucky to produce 80 or 100, giving 12 to 15 lbs oil as the whole year's supply.
 * Calories are not a big issue, as fruit and vegetables contain plenty. Steve, all those lights and fans give full climate control, so he could plant smaller crops every few weeks, to stave off the McDonald's trip. I've allowed him extra electricity to power a freezer for any excess, although drying is another storage method. Salting and pickling he won't be able to do, for lack of the necessities.
 * If the apartment is older, it would have 12 or 14ft ceilings, which helps with building up, but the floors would be timber, so the weight becomes an issue.


 * 'Proposal ONE:' We've calculated "acreage" needed for individual higher protein plants. Naturally a mixture would be better. The total area required will STILL be at least that needed for a single high-value crop. At least 400 sq.ft would have to be SOIL to provide root vegetables. My 45 tons figure could come down to maybe 30 with lighter artificial soils. It would go back up again with an additional 150 sq.ft. used for 6 or 8 espaliered trees (herbs under-planted).There would be minimum same amount of weight in water, for the hydroponic part of the operation, two or three levels high over the same 400 sq.ft.
 * The first year, the diet must be supplemented by purchased goods. The hydroponic growing mediums must always be purchased. Some compost can be bagged and sold, the proceeds spent on salt,sugar, oil and flour (or McDonald's) and baking soda ad yeast, if there are to be no eggs.
 * It would still be a good project, and reduce the necessary floor space to 300 sq.ft., if Marcus would just grow his own PLANT-BASED food, 100% of it, and still buy meat, milk, fat and salt. Are there pigeons in New York? hahaha. They could be trapped at the window and roasted or baked into pies.


 * 'Proposal TWO:' Replace the goat with a pig (fat and meat) but you'd need to buy salt to cure the meat. And take it out to be butchered. I'd not want to eat a pet, so I don't like this one. Keep a few fish in the bathtub? New fish fry would have to be bought in regularly.


 * OK I'm off to my 30 sq. ft. balcony now to harvest my tomato, leaf lettuce, basil and lemon for my dinner salad, a combination I am lucky to get right 5 or 6 times a year. With bought steak and potatoes and butter. - KoolerStill (talk) 08:38, 27 June 2009 (UTC)


 * This thing just won't fly with any traditional fruit and veggies. First there's your floors collapsing (hydroponics won't solve that and "stacked shelves" won't levitate).  Second there's the moisture issue.  Even with perfect ventilation, either it will be so dry your plants will wilt or so moist your walls will rot.  Ventilation, water processing (third party) and lighting ((about 500 MJ/m2 someone plse. do the math using standard lighting efficiency figures ) will eat much more energy than would be expended if you bought stuff off the supermarket shelf.  The only types of plants that would be conceivably suitable would be Algae and Fungi.  Finding the right species can take decades, though.  There are species of algae that produce oil, but most of the current research tends to go towards Algae fuel.  Growing fungi would cut down on your lighting requirements and would make you a bit less dependent on growing cycles.  Yeasts will also provide some essential vitamins.  Still, whatever you grow you're going to have to feed it.  Be it soil, compost, fertilizer, hay (do you guys know just how much a goat can eat each day? ) or growing substrate.  The conversion is nowhere near anything like 100% efficient.  So you are going to have to buy in tons of materials to get what little harvest you can.  Just a couple of comments on some half-baked ideas: fish won't grow in a bathtub. An Aquarium will weigh 8.3 lb per gal or 1 kg/liter.  As our article states that would give you about 1 cubic meter per 2,200 lb  plus the not inconsiderable weight of the tank.  Look at this link [] for what kind of setup you'd need to just grow a few food-size fish - nowhere near a regular source of food.  They also don't grow over-night and you'd need to feed them, pay oodles for filtration, lighting and temperature control.  Most plants are more finicky with their growing cycles than just requiring light and water.  Just because a plant has a growth period of 90 days till harvest doesn't mean you can mathematically expect it to mature out of season.  Soybean have a good modern day yield at 400g/m2 or 0.88 lb per 10.8 sq. ft. that would give you roughly 75 lb per your entire floorspace.  Even if you could find a hybrid that accepts hydroponics and could stack the plants 3 or 4 high, that just doesn't add up to all that many quarter pound veggie burgers.  Although you'd probably get a higher yield from farming algae and fungi in vats, you'd very likely starve before your year was up. 71.236.26.74 (talk) 11:25, 27 June 2009 (UTC)


 * According to TheFutureAwaits, it sounds like Marcus is a vegetarian ("into ... vegetarianism" was the exact phase). So any suggestions regarding buying meat, or of keeping pigs or fish, isn’t going to be a part of the plan.


 * As I pointed out in my message above, it’s easy to get the 10% of calories from protein you need from plant foods, as long as you eat enough calories to maintain body weight, and don’t overdo the fruit or eat junk food. The problem is not growing enough protein in the apartment, it’s growing enough calories in the apartment.  Unless the plan is based too heavily on fruit, any plan that manages to grow 2000 calories per day in an apartment will have the protein requirements met “for free”.  I gave the 11% of calories from protein for potatoes as an example, but most other plant foods (except for fruit) also have at least 10% of their calories in the form of protein.  As further examples, here are the percentages of calories from protein for a few other plant foods: acorn squash—14%, tomatoes—20%, broccoli—45%, beets—15%, corn—14.5%,brussels sprouts—47%,carrots—10%, spinach—50%.  The reason I focused on potatoes before (and legumes to a lesser extent) is because I figured that’s where most of the calories in the diet would be coming from, since the consensus seemed to be that it was impractical to grow grain.


 * The problem is, how do you grow 2000 calories per day in a 920 ft2 apartment? For example, potatoes have 279 calories per pound.  Even if all 2000 calories in the diet came from potatoes (which I’m not recommending), the 7.2 pounds of potatoes required per day would, at the density levels you listed, require 1620 ft2.   And most other vegetables (tomatoes, broccoli, beets, carrots, etc.) don’t have nearly the caloric density that potatoes do.


 * I don’t know much about hydroponics, but the hydroponics article lists potatoes as something that can be grown hydroponically, with vastly greater yields than with potatoes in soil—like 8 times as much per acre. And it lists soybeans, too, with a yield of 2.5 times as much as with soybeans in soil.  So growing 2000 calories/day in 920 ft2 is more plausible if you plan on growing potatoes as the staple, and soybeans as a supplement, hydroponically.  It does seem like it’s probably still an unrealistically difficult challenge, though, for reasons pointed out by others.  Red Act (talk) 12:47, 27 June 2009 (UTC)


 * P.S. Just to make sure it won’t be misinterpreted, in my last paragraph I wasn’t suggesting that only potatoes and soybeans would be grown.  I was just listing those two crops as being crops that should be grown hydroponically, as opposed to in soil as was being previously assumed.  There would obviously be a broad variety of other crops grown, too.  Red Act (talk) 12:55, 27 June 2009 (UTC)


 * If the nanny (when I first read that word in this thread, I though it was a lady to tend the children) or the pig is free to wander, say goodbye to the tasty vegetables. I expect that it is always going to be more efficient to eat the vegetables rather than turning them into meat.  As for weight, since there is no budget limit on this thought experiment, I will run girders between bearing walls and hang all the trays and equipment via steel cables. Does 24 hour illumination produce a higher yield for some plants than a normal light dark cycle? That could help. So could ideal temperature, moisture, freedom from bugs,birds, rabbits and deer,  and so could ideal amounts of fertilizer. Edison (talk) 20:10, 27 June 2009 (UTC)

Disciplining my kitten
I have a three-month old kitten who bites constantly. It's in play, but he just doesn't get that his playing hurts people. My hands are covered with bite marks. I've tried thumping him on the nose, squirting him with a water bottle, holding his jaws closed, and I've even swatted his behind, but nothing works. Any suggestions? Who then was a gentleman? (talk) 21:05, 25 June 2009 (UTC)


 * But you keep offering your finger. Wear gloves and don't pull your finger away, so it's not an attractive moving item to be hunted. Then HISS at him when he does it. That's the normal sound for anger, in cat talk. Follow it up with a single loud deep NO!! in human talk. Any touching him becomes part of the game, so don't touch. When he next approaches the finger, if you have time, clap your hands together very loudly, repeating the hiss and the no!.Give him toys he is allowed to bite. A piece of rope, or a thick cord like a dressing gown belt, can be wiggled like a snake, and be good to chase and satisfying to sink teeth into. Praise him for biting the cord, turn "angry" if he goes for your finger. It will take him 3 or 4 weeks to learn, by which time his probably now emerging teeth will be grown and he'll feel less need to bite anyway. This is all WP:OR as our article on cats says nothing about this. It does mention squirting against scratching furniture, and for that it does work, if the stream of water comes unexpectedly and not obviously from you. - KoolerStill (talk) 21:25, 25 June 2009 (UTC)


 * When I worked at the shelter I was told that its called 'overstimulated'. I was told that when the cat starts biting 'playtime is over'. http://www.treehouseanimals.org/Tree%20House%20Site-E-OS.htm just-emery (talk) 22:06, 25 June 2009 (UTC)


 * That's certainly what works with dogs - simply withdraw - turn your back - walk away. Wait a few minutes and then interact with the cat again.  Absolutely ANY time teeth meet flesh - immediately withdraw, turn your back, walk away again.  Rinse and repeat until moggy learns that biting equals no fun.  But you have to be fast and 100% consistant...no matter what.  Set your limit - and the very instant the cat oversteps the mark - it's game over.  You should see results in just a few days.  With dogs, it also helps if you yelp like a hurt puppy when they do it...but I have no clue what vocalisation might help with a cat.  SteveBaker (talk) 22:21, 25 June 2009 (UTC)


 * A kitten needs to use its first weeks to explore the world it finds itself in. Chasing anything that moves and sniffing, scratching and trying to bite anything that looks interesting or edible is its essential learning behaviour that humans interpret as "playing". A responsible owner can guide this learning. When kitty bites your finger push your finger gently into kitty's mouth. Kitty will learn that fingers are no fun to bite very quickly - faster than you learned not to stick toys in your mouth. The only other kind of limit you can teach a cat is the concept of territory. When Kitty does something objectionable, a HISS and a puff of air in his/her face is all that is needed to assert your right to a particular place or thing. It must be done immediately because it is difficult for a cat to understand a delayed reaction. A cat finds being squirting with water most offensive but is likely to experience that the water sprayer is a new enemy without connecting that with its behaviour. The OP seems to have mismanaged their kitty's upbringing badly. Cuddlyable3 (talk) 22:43, 25 June 2009 (UTC)


 * Please, how did you teach territory to the cat? Do you mean personal space or outdoor perimeter? ~ R.T.G 08:56, 26 June 2009 (UTC)


 * A territory I defended was my dinner plate. I allowed my cat to use our dining table by the window which was its favourite place from which to watch the world outside. My message was Food on MY plate is for ME alone! which the cat quickly learned and gracefully accepted. A hiss and a puff was all that was needed. Cuddlyable3 (talk) 17:59, 26 June 2009 (UTC)


 * Oh I thought you were out hunting with it or something, lol. ~ R.T.G 18:40, 26 June 2009 (UTC)

The dog thinks Wow these people feed me, they keep me safe, they care for me, that means they must be gods! The cat thinks Wow these people feed me, they keep me safe, they care for me, that means I must be a god! Cuddlyable3 (talk) 22:43, 25 June 2009 (UTC)


 * More detail: He isn't biting my finger, he's biting every part of my body.  My hands are covered with marks, but once the kitten wakes up in the morning, he comes running into my bed and starts biting anything and everything--arms, legs, feet, my nose.  If I'm sitting in a chair watching TV, he jumps up and starts biting.  I can't walk away every time, or I won't be able to sit anywhere.  Who then was a gentleman? (talk) 22:57, 25 June 2009 (UTC)


 * Don't worry. The cat is in the process of domesticating you. Given some time, either it will stop biting you, or you will come to love it. What's a small amount of blood loss compared to a purr from the very master (or mistress) of the universe. --Stephan Schulz (talk) 23:45, 25 June 2009 (UTC)


 * I've had a few kittens that have done this. They've all grown out of it spare one.  She still sometimes bites my wife while my wife is sleeping if there isn't any food in the food dish.  Dismas |(talk) 04:53, 26 June 2009 (UTC)


 * If you're at your wit's end, get a shock collar. You hold down a button on a remote control and he gets an electric shock.  Or hold down a different button and a tone is emitted from the collar; you'll only have to use the tone after you shock him a couple of times.  Tempshill (talk) 05:33, 26 June 2009 (UTC)


 * Try operant conditioning as stated above. Aversive stimuli or withdrawal of attention should decrease the frequency of undesirable behaviour. If he is an unredeamable attack cat, consider euthanasia. Edison (talk) 05:36, 26 June 2009 (UTC)


 * At the risk of sounding like an abusive pet owner I suggest you go with the tried and true method of spanking the animal. Use common sense when determining force. If the kitten seems to still be in pain after a few seconds, you obviously used too much force. This method works for dog, cats, and, in some rare instances, children. The behavior will cease after two weaks. But you must be consistent.


 * On the other hand, if you do not pay enough attention to your kitten, he/she will never cease the behavior, no matter how you punish it. It will see the punishment as attention, and cherish it.


 * One last thing, never. Ever. Euthanize an animal simply because it misbehaves. Shame on you Edison for even suggesting it.Drew Smith What I've done 07:09, 26 June 2009 (UTC)


 * I disagree. Considering that there are many perfectly well-behaved animals that are euthanized each year due to overpopulation,  it doesn't make sense to invest too much in those that misbehave.  Of course, in this case, it will likely stop this behavior after it finishes teething. StuRat (talk) 17:24, 26 June 2009 (UTC)


 * An alternative if there is no way to get the cat to stop biting would be to find a new owner who enjoys having a cat bite him or her. The euthanasia suggestion was for an animal which cannot be broken of biting. Edison (talk) 17:06, 26 June 2009 (UTC)


 * Spanking does NOT WORK....the only disciplines (reward OR punishment) that work are those the creature (animal or child) can associate with the actions that trigger the discipline. Older children can be told what earlier offense they are being spanked for; a kitten cannot. Shock collars may be appropriate in extreme cases for dangerously violent dogs, NEVER for playful kittens.


 * First of all, a three-month kitten is TEETHING. He NEEDS to bite.This The poor little mite also sounds like he was taken from the mother too young (under 8 weeks)and has some unsatisfied oral needs. Get him a soft plastic teething toy (sold for kittens or babies) and some WOOL (an old woolen jumper will do, but not synthetic). Put them in a large box you can close. Put the kitten in the box when he gets too bitey. This achieves isolation without having to (impossibly) walk away, plus puts him in with something he CAN chew. Talk to him comfortingly while boxing him up.


 * At night when he is asleep, put out some dry food, so he can help himself to his own breakfast without having to bleed you into getting up to provide it. HISS and NO! at him when he bites. Call him to follow you for other meals, and let him wait while you prepare it, hissing if he bites, praising if he waits peacefully. Train him to "beg" for food by hanging a (longish) strip of meat over his head, so he has to balance on two legs to get at it, praising all the while. Calm him by stroking his head from behind so he sees no biteable hand approaching.


 * Keep a sleeve of that woolen jumper near your chair, to feed to him when he jumps in your lap. Then you can cuddle and stroke him safely, and he will calm down. He will also learn he gets more attention and affection when he is acting calmly. But occasionally play a "grab the cord snake" game with him, to get rid of excess energy without harm to yourself. - KoolerStill (talk) 10:52, 26 June 2009 (UTC)


 * Drew, one REALLY last thing - never, EVER edit someone else's comments, especially to make them appear to change their position. If you have strong feeling about something, make your point and move on, but do NOT vandalize someone else's post or you risk being treated as a vandal. Matt Deres (talk) 10:45, 26 June 2009 (UTC)


 * Can I just point out, training an animal can be quite difficult depending on the temperament of the animal. We've all taking Psych 101 and think we're little experts in operant conditioning but to get the kinds of results you want in domestic animals (rather than just having your dog salivate when you ring a bell) can take a bit more than that. Consider going to the library and finding a reputable book on training; consider talking to your vet about it. Animals are complicated and have complicated psychologies. (Read a book by Temple Granden if you need some evidence of that.) Most people don't have the slightest clue how to get their animal to do what they want it to; it's usually simultaneously both harder and easier than one might expect. Animals do not reason about the world the same way we do, and thus any training program has to be arranged from their odd little points of view. --98.217.14.211 (talk) 15:07, 26 June 2009 (UTC)


 * This may sound stupid, but just live with the cat. Don't do anything. Is the cat killing you? It will probably outgrow the biting stage. It will adjust to you, and you will adjust to it. You should be glad it has mind of its own, even if it is infuriating. Or put it up for adoption. Be fully open with any prospective owner about the problems. Or give it to a shelter. But I am not so sure that there are answers to idiosyncrasies. This will also sound stupid -- but cats can read your mind. They are not completely unaware of how you feel about them and about their various behaviors. Even if a cat is not looking at you I think they can tell what your attitude is to them. I think it is better to under-react than to over-react. Over-reacting runs the risk of misunderstanding. But under-reacting will eventually be figured out by the cat. If you merely express mild disapproval the cat will eventually get the message. Bus stop (talk) 17:28, 26 June 2009 (UTC)


 * This is the science desk, not the "lets be cute about cats"-desk. Cats are NOT telepathic.  Telepathy doesn't exist.  Cats are small mammals with relatively small brains.  Much like dogs, they are probably pretty good at reading body-language because that's mostly how they communicate with each other in the wild...which to the uncritical thinker might come over as "telepathy" because humans are relatively poor at understanding body language - but it's not telepathy.  That's why using body language to express yourself to your cat/dog works so well.  The cat is a simple learning machine - the algorithm for which is something like:
 * You want something (let's call it 'X').
 * Try some random behavior (let's suppose you pick 'Y').
 * Did 'X' happen?
 * If "Yes" then...
 * Increase the probability that you'll pick 'Y' in the future.
 * Do 'Y' again.
 * Go to 3.
 * If "No" then...
 * Decrease the probability that you'll pick 'Y' in the future.
 * Go to 2.
 * In this case 'X' is probably something like 'Get attention' and 'Y' is obviously 'Bite'. So the way to get your cat to stop biting is to cease giving it attention immediately it even looks like biting...and to give it all the attention it wants when it randomly happens to try doing something cute.  If the cat is indeed teething - then you obviously need to provide things for it to chew...and make it clear which things those are.  That way you get a cute cat - not a bitey one.  Punishment doesn't work well when 'X' is 'Get attention' because while the cat may not enjoy being punished, it still meets the 'Get attention' criteria - so you just end up with a mean, nervous 'bitey' cat.  It's worked with every dog I've ever owned - I'm pretty sure it'll work with a cat too.  Our lab/retriever loves to play 'rough' - she loves to make a great display of snarling, snapping and jumping around - her teeth will come within a hairs-breadth of your skin - and may even brush gently against it - but no pressure whatever is ever applied.  When she was a 6 week-old puppy - she was all teeth - but simply ignoring her and becoming a very boring owner whenever teeth touched skin was enough to teach her a life-long lesson in just a few days.  But the entire family has to work at it - and the turning off of attention has to be immediate and obvious and 100% consistent. SteveBaker (talk) 18:10, 26 June 2009 (UTC)

The "kitten" of the OP could be a young beaver, hedgehog, rabbit, rat, skunk or squirrel, but we assume it is a felis catus - domestic cat. I have kept several cats and they have been relationships with exquisitely sensitive, graceful and highly evolved pets. Some points for maintaining a good cat-human relationship are to introduce yourself to the cat by inviting the cat to sniff your hand before any kind of physical interaction, and to stroke especially the sides (cheeks and ears) of the cat's face. Both those points are due to the cat's reliance on scents, yours and it's own, to identify who is whom. I support the post by KoolerStill who with Bus stop seem the only posters here fit to be trusted with a cat, in the midst of the above appalling accounts of supposedly responsible humans abusing a small animal that is, by their choice, dependant on them. Cuddlyable3 (talk) 18:32, 26 June 2009 (UTC)


 * I admit the cat is not telepathic. I stand corrected. I don't believe there is such a thing as telepathy. But there are means of gauging humans that cats may have that we don't understand. They are probably the usual senses, but enhanced or in different ranges. One point that I would stick by is that a little bit of communication goes a long way. I think the human/cat interface is poorly understood. I think that in many instances if you are going to try to explicitly communicate with a cat you are running the very real risk of the wrong message coming across. As far as the original questioner's cat biting him, I strongly suspect that something that is being done is actually strengthening the biting behavior. Or there is some unexplained and unexplainable reason for this, in which the cat should probably be given away. I really don't think something as idiosyncratic and odd as a cat biting you first thing in the morning! while you are still sleeping! is going to be addressed by any explicit response. My hunch is that by doing very little the cat will nevertheless get the message. As long as your response is displeasure, and the original questioner is clearly indicating displeasure, then I think that displeasure is going to be communicated. My hunch is that by doing nothing, this behavior is eventually going to stop. If it persists for months I would give the cat away. Bus stop (talk) 21:04, 26 June 2009 (UTC)


 * I was once highly skilled in training rats and pigeons. But instinct trumped operant conditioning every time. Chickens who were rewarded for pecking a little piano keyboard would scratch the floor, for no apparent reason, due to instinct. As for attack cats, I have known a few, and it was due to kids rough-housing with them and encouraging attack behavior.  If a given person cannot train and control a cat, perhaps someone else can. I have seen vast differences in the ability of bright college students to condition a rat or a pigeon to perform a desired behavior or to avoid an undesired behavior.  One trick is to place something which tastes aweful (Tabasco?) on the spot they bite. This is akin to a shock collar.  I was able, with judicious application of electricity, to train cats not to touch the birdcage. A squirtgun is a fairly harmless device to discourage undesired behavior by a cat. What would mama cat have done to bring up her young not to misbehave? A hiss and a harmless slap. A loud "NO" is something a cat should learn to avoid.  Consistency and promptness are essential in operant conditioning. But there is backsliding, so successive approximations of the desired behavior are used in shaping a response. A quick consistent correction can discourage undesired behavior. If attention is what the cat wants, then "bad behavior" gains "attention" is a recipe for unhappiness. Mild but swift punishment for misbehavior and withdrawal of attention for misbehavior, and lavish praise and attention for good behavior is the way to go. Cats are not easy to train. I trained one to jump up in my lap on voice command, and to lie down on voice command, and to run to the kitchen to get a can of cat food on voice command. Harder to train than horses, dogs, rats parakeets or pigeons. Edison (talk) 02:43, 27 June 2009 (UTC)
 * The creature with the superior intelligence is the one who has to adjust to the understanding level of the other. There are videos hereand here of a Russian cat circus, starring over 100 cats which were picked up as strays. I saw a TV interview once with the owner. He said training has to be entirely trust and affection based. "If you hit a cat just once, it will never come on stage again" he said. I have a cat that spent her first 7 years hiding under a bed from an abusive owner; she now runs to greet visitors and is confident outdoors (that took 18 months). I have another, adopted as an abandoned 9-month-old over the objections of rest of the household ....so he kept looking to me to veto what others told him (mostly "get lost"). He came to trust me to the point of accepting walking on a leash from the first attempt (for a 3-day road trip) and obeys sign language commands for come here/there/up/down/away-from-that. All done with praise and trust, no punishment.- KoolerStill (talk) 09:25, 27 June 2009 (UTC)
 * I second the "friendly reminder" training approach. If you can't withdraw yourself, then move kitty promptly to the bathroom and close the door for some time-out if he bites you.  (Even if you have to boot yourself rapidly in the morning to do so.)  After a short while pick kitty up and cuddle him in a mildly constraining way (wrap in a towel if nothing else works for you) so he can't bite you, pet him gently and talk to him in a soothing voice (aka corporal cuddling ;-).  Speaking of voice, "ee" and "ae", "itty", "ikky" and "brt" sounds sound friendly to cats, while "oo", "ou", "gr" and hissing noises sound hostile.  Try to control the noises you make.  Then put in some play time with a toy on a tether or offer a treat.  Never offer your hands, or any human item like gloves or socks to your kitten as a toy.  Older kittens may have learned the difference between a sock with a foot in it and an old sock used as a toy, this one hasn't yet.  OR I once had a 20 lb tom hanging from my behind because he wanted to play with the strings of my apron. Yowl!  Thumping him on the nose and holding his jaws shut would just be interpreted as a part of your way of roughhousing and your kitten is unlikely to get that it overstepped some boundary.  Withdrawing (yourself or him) is sending the message that you don't want to play.  IMHO a shock collar would only get you a neurotic cat.  Consistent response, persistence and patience will do the trick.  (Another bit of OR: our cage full of wild cats would behave like the sweetest house cats when someone entered the enclosure carrying a broom.  Loose the broom and they would attack.  No one had ever threatened or hit any of them with a broom.  It was just a symbol to them that you were in charge.) 71.236.26.74 (talk) 12:37, 27 June 2009 (UTC)
 * I'm not convinced by "time-outs". Is the cat really going to connect the time-out to the prohibited action? If you're going to move your cat as part of the punishment it needs to be done by picking them up by the scruff of the neck, anything else will likely be interpreted as a positive thing (or will make them associate being picked up with being punished, which would be unfortunate). --Tango (talk) 19:34, 27 June 2009 (UTC)
 * You treat picking up by the scruff as a negative, punishing action? Undignified perhaps, but tapping into being-mothered sensations. Certainly it would likely be needed if you're going to move a bitey, overexcited cat quickly, but that's only because it sends the cat into good-kitten-being-carried mode. (and I generally wouldn't recommend lifting by the scruff to someone that I'm not going to be around the first 5 times they try) 89.168.19.118 (talk) 20:16, 27 June 2009 (UTC)

Earth's core as Time Keeper
Could a clock be invented that uses magnets, the Earth's core, or the Earth's rotation as the means of keeping time? --Ye Olde Luke (talk) 23:10, 25 June 2009 (UTC)


 * Earth's rotation? See sundial. For the others, no, I don't think so. There is nothing periodic about them. --Tango (talk) 23:12, 25 June 2009 (UTC)
 * Or Foucault pendulum, which is perhaps more interesting. --Tango (talk) 23:16, 25 June 2009 (UTC)

To be more specific, is there a type of clock that would stop working correctly if taken away from the Earth and to, say, a different planet? --Ye Olde Luke (talk) 23:22, 25 June 2009 (UTC)


 * Sure, any pendulum-driven clock depends on Earth's gravity for its timing. &mdash; Lomn 23:34, 25 June 2009 (UTC)
 * (ec) A grandfather clock or any other clock with a pendulum will not work correctly away from the Earth - the rate at which a pendulum swings is dependant on the length of the pendulum and the strength of gravity (but, interestingly, not on the weight of the pendulum). If you go to a planet with different gravity it will swing at a different rate and will tell the wrong time. The principle still works anywhere with gravity, but you would need to alter the clockwork or the length of the pendulum or something to compensate. Obviously sundials and Foucault pendulums won't keep time properly either. I think any other common method of keeping time will work. Quartz will oscillate the same way wherever you are, for example (if it is kept at the right temperature, anyway). --Tango (talk) 23:37, 25 June 2009 (UTC)
 * Would an egg-timer keep good time on Mars? A water clock?  I kinda doubt it.  Candle clocks are a bit of a non-starter! SteveBaker (talk) 00:39, 26 June 2009 (UTC)
 * Egg-timer I'll accept (although I really don't know if gravity is a factor there or not, it wouldn't surprise me if it was, but I'm not sure either way). Water and candle clocks I don't accept as "common". --Tango (talk) 00:51, 26 June 2009 (UTC)


 * By egg-timer do you mean a sand-glass? That runs on gravity, as do water-clocks. (I wonder whether the speed of a sand-glass is linear with respect to gravity.) —Tamfang (talk) 17:33, 27 June 2009 (UTC)


 * So, a Foucault Pendulum clock depends on the Earth's rotation, and a normal pendulum clock depends on the earth's gravity. I suppose you were hoping for something more exotic, I wonder if a Foucault "pendulum" clock could be made with a gyroscope instead of a pendulum. That'd be pretty cool, but I suspect that it wouldn't really work, minor faults in the gyroscope would overwhelm the effects from the Earth's rotation. APL (talk) 00:24, 26 June 2009 (UTC)
 * A gyroscope should work, yes. Very precise gyroscopes have been created for things like Gravity Probe B, although they were in zero-g. I expect it could be done if somebody wanted to. --Tango (talk) 00:51, 26 June 2009 (UTC)


 * I suppose that you could build a very precise compass needle and track the motion of the magnetic poles in some clever way. The North pole drifts around at between 10km to 50km per year - a super-accurate compass could be used to drive some kind of mechanism and thereby obtain a clock of sorts.  Sadly, the rate and direction of magnetic pole's movement changes from year to year - and it's not readily predictable over more than a few years - but you'd probably be able to get pretty reasonable accuracy if you recalibrated your clock every few weeks.  But the precision of this machine would have to be spectacular in order to measure such a slow change accurately enough to use as a clock that would read hours and minutes.  I doubt that it's a practical proposition. SteveBaker (talk) 01:00, 26 June 2009 (UTC)


 * It also depends on what level of accuracy you require. Geomagnetic reversal has been a useful method for timing events on a geologic time scale; events like Plate tectonics were only able to be put into a proper temporal relationship once Geomagnetic reversal was understood.  So, as a "clock" whose "second hand" ticked every hundred thousand years or so, the Earth's magnetic field could be quite reliable.  However, working on the human timescale, probably not.  --Jayron32. talk . contribs  01:35, 26 June 2009 (UTC)


 * The problem with using geomagnetic reversal as a clock is that it only works if it has first been calibrated using another clock. The orientation of the Earth's magnetic field appears to wander chaotically; given all the historical data we have, plus all the information on Earth's current field, we still can't predict which way the pole will be pointing fifty or a hundred thousand years in the future.  In other words, it doesn't 'tick' uniformly, and it's only useful if you already know what year it is. TenOfAllTrades(talk) 13:47, 26 June 2009 (UTC)