Wikipedia:Reference desk/Archives/Science/2017 October 6

= October 6 =

Can electron quantum tunnel out of a black hole?
If a single hydrogen atom is just at the event horizon of a black hole. Can it's electron quantum tunnel from inside the event horizon to outside it. After all, its location is just a wave function and half of the wave is inside the event horizon and half of the wave is outside the event horizon. 110.22.20.252 (talk) 01:56, 6 October 2017 (UTC)
 * Hawking radiation is at least a bit relevant. Sagittarian Milky Way (talk) 02:15, 6 October 2017 (UTC)


 * Yes, there are generally theories that quantum mechanical effects will allow particles to escape from black holes, albeit with a very low probability. However, as we lack a comprehensive theory of quantum gravity or any direct experimental access to black holes, I would suggest such ideas are rather speculative at present.  I would note though that unless you have some magic way of suspending matter right at the event horizon, then the atom is likely to be falling into the black hole at very high speeds.  The amount of time that any atom might be considered half-in/half-out of the black hole is likely to be extremely small for any normal black hole.  The situation is more interesting in the case of microscopic black holes, if such entities actually exist.  It is possible to imagine, at least in theory, black holes so tiny that particles like electrons are essentially too large to fit in the black hole and even after being eaten there is an appreciable chance that they leak back out again.  Again though, this all rather speculative and untested.  Dragons flight (talk) 02:55, 6 October 2017 (UTC)


 * Jak skazal SMW, see Hawking Radiation. μηδείς (talk) 00:50, 7 October 2017 (UTC)


 * What does jak skazal mean? Sagittarian Milky Way (talk) 01:18, 7 October 2017 (UTC)


 * In what language? User:Sagittarian Milky Way? In Spanish it's "como dijo". μηδείς (talk) 22:26, 10 October 2017 (UTC)


 * User:Medeis: I don't know, it's your language. The Spanish version sounds like Google Translate. Sagittarian Milky Way (talk) 23:02, 10 October 2017 (UTC)


 * As he said.... μηδείς (talk) 23:26, 10 October 2017 (UTC)

Limit of temperature generated by electricity
Hi again ref desk, another impossible to Google question. I heard on a podcast about converting the world to renewables, that creating steel requires around 3000°F and they claimed that using electricity alone, you can't get to those temperatures. So, is this true? If so, given an infinite amount of power, is it a law of diminishing returns? I was thinking they could just turn large chunks of iron into filaments (however impractical) to accomplish this. Anywho, thanks in advance. Drewmutt ( ^ᴥ^ ) talk  04:35, 6 October 2017 (UTC)
 * No, not true at all. Our article on electric arc furnaces says that they can reach temperatures of 3,000 °C (5,432 °F). 2601:646:C101:C8A2:34D5:864B:CE64:F9CD (talk) 05:46, 6 October 2017 (UTC)
 * That just the furnace. The actual arc is hotter.
 * "Electrical arcs produce some of the highest temperatures known to occur on earth, up to 35,000°F (19,426°C). This is 4 times the temperature of the surface of the sun which is about 9000°F (4982°C)."
 * BTW, it took me roughly a minute on Google to find the answer to this "another impossible to Google question". I'm just saying. --Guy Macon (talk) 06:53, 6 October 2017 (UTC)
 * If you want people to Google better themselves, it would help if you included the search strings you used. Sometimes you have to know something about a subject in order to Google it effectively and it's hard to not end up with tangientally-relevant but much more popular results. --185.216.49.78 (talk) 11:42, 8 October 2017 (UTC)
 * (ec)Maybe we should also mention that many high-quality steels are routinely produced in electric arc furnaces (and have been for at least decades), because they offer more control over the chemical composition of the steel (there is no coal to introduce carbon, or other undesirable impurities coming with coal, like sulphur and phosphorous), and they also make the physical process easier to control. Of course there also is a red herring - just because it is hard to replace some fossil fuel applications does not mean that we cannot reduce carbon emissions to a sustainable level - most carbon emitting processes can be replaced or improved. --Stephan Schulz (talk) 10:00, 6 October 2017 (UTC)


 * As pointed to above, the problem is not the maximum temperature. But a key consideration is that coal is used to bring not only heat but also carbon content to the steel in blast furnaces (historical note: Wootz steel), which can help the economics of coal vs. electricity - you would need a source of carbon if you heated by electricity.
 * Blast_furnace says that there have been electrical blast furnaces in Sweden but I cannot track down a source. I found this report considering switching to biomass (which counts as "renewable" by most standards). Tigraan Click here to contact me 09:46, 6 October 2017 (UTC)


 * I would also note this, from our article on Tantalum hafnium carbide: " Tantalum hafnium carbide is a refractory chemical compound with a general formula TaxHfy-xCy, which can be considered as a solid solution of tantalum carbide and hafnium carbide. Individually, these two carbides have the highest melting points among the binary compounds, 4,150 K (3,880 °C; 7,010 °F) and 4,201 K (3,928 °C; 7,102 °F), respectively, and their "alloy" with a composition Ta4HfC5 is believed to have a melting point of 4,263 K (3,990 °C; 7,214 °F). Very few measurements of melting point in tantalum hafnium carbide have been reported, because of the obvious experimental difficulties at extreme temperatures.  " (Emphasis added) --Guy Macon (talk) 16:20, 7 October 2017 (UTC)

Global warming
So when people think global warming is made up, what is their reasoning for why they think scientist would just make it up? Is it just random conspiracy nuts? C T F 8 3 !  09:30, 6 October 2017 (UTC)
 * It's very much not random - it's carefully seeded by people and organisations that profit from the old-school carbon-based economy and want to reduce or delay changes. A modern classic on the topic is Merchants of Doubt, but you will find plenty of additional sources via Google Scholar. --Stephan Schulz (talk) 09:40, 6 October 2017 (UTC)
 * There are not many global warming denialists. Temperature is quite easy to measure after all. Denialists mostly deny it's man-made, and hence, believe nothing should be done.
 * They normally explain the consensus as a result of aggressive activism, as a Chinese invention, or whatever. See Global warming conspiracy theory for the whole story. --B8-tome (talk) 11:45, 6 October 2017 (UTC)


 * To be fair, those of us who grew up in the 1960s and 1970s were regularly served up gloomy scientific predictions; the world would run out of food or water (or both) at some time in the 1970s, we could be thrown back into the stone age by a power cut, we would completely run out of oil in 1984 and millions would die when the next ice age arrived early in the 21st century. So although I agree fully with what Stephan Schulz says above, there has been an awful lot of crying wolf beforehand, so some scepticism is understandable.  Alansplodge (talk) 12:06, 6 October 2017 (UTC)
 * @Alansplodge: If I'm not mistaken global cooling has always been a minor view among actual climatologists. People who naïvely noticed that recent interglacials are about 10,000 years long didn't realize that the Milankovitch contribution is about as bad as it'll get for many thousands of years and yet glaciers still aren't advancing as they must for an ice age to start (Little Ice Age was temporary) and we've got about another 10,000 years left. And didn't realize that every 400,000 years there's an especially long interglacial (4 ice ages ago is so long ago that its topographical features are almost obliterated by now and ice cores that deep didn't exist in the 70s) Also humans add carbon dioxide on top of that so of course there's not going to be another ice age for many thousands of years. Sagittarian Milky Way (talk) 23:42, 10 October 2017 (UTC)
 * We know now all about the Milankovitch cycles and the increase in carbon dioxide, but things were not as clear in the 1960s, and global warming seemed to have stopped (we now know why). The media seemed to be convinced that another ice age was on its way, and probably found climatologists who supported their scaremongering.  I recall no climatologists who challenged their view, but that might just have been because that viewpoint didn't make good news at the time.    D b f i r s   00:05, 11 October 2017 (UTC)
 * World population growth rate 1950–2050.svg one thing really helped with the running out of food and water: the population growth rate stopped rising and halved. Now if we can just get people to stop making baby so much, especially in the places where the new human will be given a life of poverty and war over limited resources, then a lot of the 21st century problems could be ameliorated for free. Cause no one wants to be unborn once they're already sentient and once the cat's out of the bag we have to let them consume scarce planet for a century. (well very few) Sagittarian Milky Way (talk) 01:24, 11 October 2017 (UTC)


 * The reason I've heard is funding, that if global warming wasn't real, climatologists risk losing their funding. A Quest For Knowledge (talk) 12:15, 6 October 2017 (UTC)
 * Because as a rule scientists are motivated by money and choose their profession because scientific careers pay so well? Or because there is a hive mind controlling all scientists? Note that anyone who puts a serious dent into a widely accepted theory would be set for life - compare Albert Einstein (who killed Newtonian mechanics), or Barry Marshall and Robin Warren, who showed that most gastric ulcers are caused by infections, and not (directly) by stress and diet. --Stephan Schulz (talk) 13:37, 6 October 2017 (UTC)


 * It isn't just because it is in the interest of some very big companies, there is also a desire in people to not believe they are doing any wrong by driving cars or taking holidays by plane or any of the other countless good things of modern life that need fuel to be burnt. And in particular in America it basically says you can't be altogether free to do whatever you like which is one of the beliefs the country was built on. So lots of people are quite happy to engage in what psychologists call denial. Dmcq (talk) 13:55, 6 October 2017 (UTC)


 * As hinted above, there is a habit of grouping anyone and everyone who disagrees with anything at all about global warming into the "stupid denier" section. If I were to point out a prediction from Gore's Inconvenient Truth that didn't happen, I would immediately be as much of a denier as some guy who claims that it is all made up by the illuminati. 209.149.113.5 (talk) 17:25, 6 October 2017 (UTC)
 * That is simply not true. Scientists were quite happy to point out some problems with the film An Inconvenient Truth. They didn't however make the leap from that Al Gore made some mistakes in his film to that global warming isn't happening. Dmcq (talk) 15:37, 7 October 2017 (UTC)
 * Ok thanks all! C T F 8 3 !   17:30, 6 October 2017 (UTC)


 * It is because the vast majority of lay people (whether they have doubts about global warming or not), don't know much about how science works in practice. In particular, they lack knowledge about the rigorous review procedures. The way the media reports on science in general, not just about climate change, doesn't help. There is usually nothing in news reports about science that gives you any clues how the review processes work. Because usually the news media will try to interview the leading experts in the field, this then leads to a skewed picture of how science works, it then looks like professors ultimately decide what is going to be accepted as proven facts. Then some lay people will find that reasonable, while other people who have read elsewhere that all these professors are left wing liberal tree huggers, cannot be trusted, will have severe doubts.


 * Contrast this with the justice system. People know a lot more about the procedures of that system and the way the media reports about crime and court cases usually will contain something about the relevant procedures. Then, without even reporting about the details of the evidence that led to a conviction, most people will typically accept the verdict. In exceptional cases there may be doubts, but even in such cases were someone is alleged to have been wrongly convicted, will people still argue that there should be a retrial based on e.g. new evidence. So, people know about the procedures of the system and at most they would want a new hearing within the system. In case of global warming, the deniers buy into arguments presented outside the system and they want conclusions reached via the procedures of the system to be ignored. That's analogous to releasing someone convicted of murder based on a newspaper editorial without going through the procedures set out for that (e.g. appeal and retrial or applying for parole or pardon). Count Iblis (talk) 19:26, 7 October 2017 (UTC)


 * The OP's asking why some people question global warming. That is a political debate if lay people (or corporations, who are legally "people" when voicing opinions in the United States, under the Citizens United Supreme Court ruling). That fork of the discussion   properly belongs in Reference desk/Miscellaneous.
 * If climatologists and meteorologists with solid credentials question some aspects of global warming theory, as Science and Operations Officer at the US National Hurricane Center Chris Landsea does, it's a scientific debate and belongs here.
 * I mention Dr. Landsea as an example of a scientist with undeniable credentials who does question the common assertion that hurricanes are becoming significantly more intense and common because of global warming. Dr. Landsea thinks the contribution of global warming to hurricane wind speed is at most a one to two percent increase.
 * While a research meteorologist at the University of Colorado at Boulder, Dr. Landsea withdrew from taking part in the IPCC Fourth Assessment Report because its sponsors, the United Nations Intergovernmental Panel on Climate Change (IPCC). In his resignation letter Landsea cited his reason for doing so was "a process that I view as both being motivated by pre-conceived agendas and being scientifically unsound." Dr. Landsea claimed the IPCC had become politicized and their leadership ignored his concerns while he took part in the study they sponsored of hurricane activity and global warming before he left.
 * So, to answer your question, OP, people can question global warming theory (especially as explained by the IPCC for political motives such as the ones mentioned by other posters here, or on scientific grounds. Dr. Landsea was concerned specifically that the IPCC publicly cited a paper of which he was a co-author before the researchers had finished analyzing their data (the IPCC stated their preconceived notions, not the actual data and conclusions of that important study - they not only lied to the public, but in the names of the people doing the actual research).
 * There are instances on both sides of the scientific debate on global warming in which faulty logic and analysis, not to mention scientific malpractice amounting to fraud were present. loupgarous (talk) 10:27, 9 October 2017 (UTC)
 * As to hurricanes the IPCC makes no strong predictions about them in the near term. This talk of 'common assertion' does not have any basis in fact as far as climate scientists are concerned. If there is a difference with what Chris Landsea said I can't spot it but scientists do go off in a huff sometimes over small differences. My guess is it was the organizational and political aspects that really irked him. I think this 'common assertion' is probably media headlines of the type 'Has climate change increased the severity of hurricanes?", in such cases take account of the question mark - it is because they don't have any basis but want a good headline and they can always selectively quote things like The Impact of Climate Change on Natural Disasters to give an apocalyptic slant. Dmcq (talk) 12:55, 9 October 2017 (UTC)

Is there a wikipedia article debunking the "Never Adjust for Curvature of Earth" claim of Flat Earth?
Is there a wikipedia article debunking the "Never Adjust for Curvature of Earth" claim of Flat Earth? Basically the stupid argument of flat earthers is that an aeroplane flying level on a spherical earth would fly off into space. Since the pilot of the plane NEVER adjust for curvature of the earth, the only conclusion a sane person can draw (with his kindergarten crayon) is an earth that is as flat as a pancake.

I know how to debunk it, it involves the vector from the centre of mass of the aeroplane to the centre of the earth. The aeroplane naturally balances itself on the centre of the mass, in the direction of the centre of the earth. So just imagine the aeroplane like a see saw with the pivot being the centre of mass of the plane. However it takes too much words, diagrams and effort to explain the idea to the Flat Earthers. So I am looking for a wikipedia article to explain this concept so that I can just direct them to the article. 110.22.20.252 (talk) 10:21, 6 October 2017 (UTC)


 * Gravity adjusts the plane for curvature of earth. That's like Earth is longeing the plane.
 * PS: I hope you don't meet many flat-earthers in your day to day. I have some just through the internet, and thought they were a parody of creationists. This was a classical case of Poe's law. --B8-tome (talk) 12:01, 6 October 2017 (UTC)
 * If those flat-Earthers admit the existence of gravity anomaly, it might be a starting point to argue that "gravity is not always vertical" (or rather, that if by definition vertical = in the direction of gravity, all verticals on Earth are not parallel), and the plane goes perpendicular to the gravity field, etc. But I am not sure of what is causing g in their world model, so... Tigraan Click here to contact me 12:11, 6 October 2017 (UTC)


 * There are a few effects here. Conservation of energy is one, things just don't change their gravitational potential energy unless there is some trade of energy going on. So planes don't change altitude against gravity unless they're either driven by their engines, they perform a zoom climb and trade speed for altitude, or light gliders might climb in a thermal.
 * Then there's the classic balance between lift and weight, thrust and drag. When these are balanced, there's no vertical movement (Note to Newton - there's no vertical acceleration because they're balanced. But there's also no vertical speed because of the work against the gravitational field).
 * Finally there's the angle of attack issue. Aircraft move vertically because of the lift/weight imbalance. But flat earthers think aircraft "go where they're pointed" and so presume that any aircraft pointing "up" flies in that same direction.
 * Underlying all of this though, is the flat earth refusal of either gravity (at all) or their belief that gravity acts parallel and perpendicular to a flerf, rather than symmetrically and radially. Andy Dingley (talk) 12:15, 6 October 2017 (UTC)


 * Wikipedia has an article Flat Earth but does not as far as I know address this claim. If you get a reliable source discussing it then you could try adding it somewhere I guess. However I don't see the point of the question. No flat-earther is going to be convinced by some rational scientific argument about what a plane does or gravity or whatnot if they think pictures of the earth from space are part of some conspiracy theory. Dmcq (talk) 13:48, 6 October 2017 (UTC)


 * Flight instruments would appear to be relevant.  The pilot will use his instrumentation to ensure his craft is an appropriate distance above the ground.   This is important because aircraft are segregated laterally and vertically. 92.8.220.234 (talk) 15:19, 6 October 2017 (UTC)
 * So do you follow the flat earth claim here? That aircraft only maintain altitude, rather than flying straight above an Earth curving away beneath them and so heading off into space, because the pilots are deliberately steering them downwards?
 * Perhaps we need an article on the legal fallacy of riding two horses as well? Globe Earth aircraft maintain a constant altitude as an equilibrium, because of gravity. The same gravity shapes the form of the Earth too, so we end up with a constant gravitational height approximating a constant altitude over a plain. This is the same case for both globe and flat earth models.
 * The fallacy of flat earthers claims about aircraft depend on two underlying fallacies. Firstly that aircraft climb "by pointing upwards", rather than by having an excess of lift. Secondly, a flat earth aircraft would fly straight and level above a flat earth, and a globe earth aircraft would follow the same altitude around a globe Earth. The fallacy is to claim that a flat earth aircraft, following flat earth physics, would somehow be above a globe Earth, dropping away beneath it! Aircraft over a globe Earth are flying by globe Earth physics. Andy Dingley (talk) 15:50, 6 October 2017 (UTC)

This is serious. This is NOT A LAUGHING MATTER. THIS IS SO SERIOUS THAT a man took a spirit level on an airplane to prove that the earth is flat. [Man takes spirit level on an airplane]. 110.22.20.252 (talk) 16:42, 6 October 2017 (UTC)
 * The easiest way to understand why a plane does not fly off the Earth is to consider the frame of reference fixed with respect to that plane. In such a frame the plane is not moving at all but instead the Earth rotates beneath it. The air follows the Earth and moves relative to the plane creating a lift that balances the total gravity force. So, it is not surprising that plane stays bound to the Earth. Such a frame is, of course, generally non-inertial save one special case. However one of the two inertial forces – centrifugal force – is just added to the true gravity forming the total gravity force and is essentially unobservable. The second inertial force – Coriolis force – is small (depending on velocity relative to the plane) although it will readily reveal itself once you conduct a Foucault pendulum test. Ruslik_ Zero 18:26, 6 October 2017 (UTC)
 * You are not going to convince a flat-earther with rational argument. See Duty calls for what I think about your capital letters about that this is so serious. Dmcq (talk) 18:49, 6 October 2017 (UTC)
 * Flat-earthers don't believe in gravity; they believe that the earth is accelerating upwards at the rate of gravity. If you think the Earth is a globe because you can see the curvature of the horizon, try this: take a long pole that you know to be perfectly straight from sighting along it. Grasp it at its centre with one hand; hold that arm out in front of you at full arm's length so that the pole is horizontal and level with your eyes. Look at the hand. Do you see anything unusual about the pole in your peripheral vision? Explain that. Akld guy (talk) 21:15, 6 October 2017 (UTC)



Talk about the amount of ignorance of physics. 99% of the youtube videos explaining why the airplane does not fly off the earth in a level flight is COMPLETELY WRONG. Right result but wrong explanations.


 * The air get more rare as the altitude increases, Therefore the airplane must curve with the shape of the earth. CORRECT STATEMENT but wrong explanation, I can prove this if you replace the plane with a rocket and take away all the air by moving it to the moon. A rocket with thrust (directed towards the centre of the moon) that perfectly balance out the force of gravity over the moon, will still curve with the shape of the moon. The air get more rare explanation is wrong.


 * Gravity makes the airplane confined to a certain altitude above the earth. TRUE but how?


 * The autopilot of the airplane keeps it curving with the earth. WRONG. The airplane will still curve even with no autopilot.


 * The trim of the airplane keep it curving with the earth by keeping it "level with the horizon". WRONG. See rocket on moon explanation. Trim needs air to work on an airplane.

The true answer is that the airplane is like a (weighing) balance scale which naturally balances itself by the centre of mass located at the centre of the aircraft by the wings. As the airplane travels an infinitesimal distance to the right, the front of the airplane dips down an infinitesimal amount and the tail of the airplane rises up an infinitesimal amount. This is because the airplane is like a (weighing) balance scale or a see saw. As it moves to the right, the vector from the centre of mass of the airplane to the centre of the earth changes. So the airplane becomes "unbalanced" and like a (weighing) balance scale or a see saw, it will naturally rebalances itself to make it level according to the new gravitational field. You can say the airplane ALWAYS forms a right angle triangle from the front of the airplane to the centre of the airplane to the centre of the earth. You don't need autopilot and you don't need any other explanation. 110.22.20.252 (talk) 04:09, 7 October 2017 (UTC)

It actually is possible, in theory at least, to use an airplane to test for a flat Earth. If you have an east-west route near the Equator, the Earth gravity you feel is adjusted downward (normally) by 0.3% for centrifugal force. Thus, if you fly 500 mph East, you should weigh about 0.15% less (adding to your speed and the centrifugal force), and if you fly 500 mph West, you should weigh about 0.15% more. In concept an analytical balance can weigh things to this accuracy. The caveat is, I have a hard time picturing that the vibration typical of a commercial flight would actually let you weigh that precisely. But I've never taken an analytical balance on board a plane! (Probably get sent to Guantanamo Bay just to be 'on the safe side') Wnt (talk) 06:21, 7 October 2017 (UTC)
 * Well, the basic plan is good. With a 100kg reference mass, you should notice 300g of difference going one way or the other. To handle vibration, just take a time series for each leg and average the results. There are two caveats: A balance (in the narrower sense) is useless, as the same reduction applies to the reference weights. You need a good weighing scale that directly measures force. Also, using yourself as a test mass is not a good idea - even if you skip the aircraft food (a small sacrifice, ok), it will be hard to maintain exact weight for a sufficient time, due to sweating and breathing. --Stephan Schulz (talk) 06:47, 7 October 2017 (UTC)
 * Wups, clearly you're right about the analytical balance - I should watch those last-minute "improvements". And no, you couldn't literally use yourself for a test mass... not unless you're one of those new robotic airline pilots, anyway. Wnt (talk) 10:49, 7 October 2017 (UTC)

Name of 'Bill Gates just walked in the room effect'
How would you call the statistical effect on income/personal wealth colloquially called 'when Bill Gates just walked in a room'?--B8-tome (talk) 11:41, 6 October 2017 (UTC)


 * ?? ? Andy Dingley (talk) 12:04, 6 October 2017 (UTC)


 * This is related to the Ecological fallacy - the mistake of making assumptions about individual members of a group based on group averages. That article discusses a similar effect where the average wealth of US states is distorted by the super-rich. Smurrayinchester 12:09, 6 October 2017 (UTC)


 * Don't know the name, but this is used to show the importance of using median incomes instead of average incomes. If you have a billionaire in a room with a thousand homeless men, their average income makes them millionaires, but saying "the room contains a thousand people, who, on average, are millionaires", is highly misleading.  Yacht salesmen would be advised to look elsewhere.  The median income correctly shows that most people in the room are dirt poor. StuRat (talk) 14:21, 6 October 2017 (UTC)


 * This effect might work out to the benefit of Paddock's victims, given his supposedly high net worth, as long as they take Hamlet's advice on the lawyers. μηδείς (talk) 19:32, 6 October 2017 (UTC)


 * In statistics it is known as the outlier problem. Looie496 (talk) 13:17, 7 October 2017 (UTC)


 * Not sure if that's quite right. The problem with incomes is they do not follow a bell curve, but are extremely lopsided.Thus, any statistical methods based on even distributions, like averages, don't apply to incomes. StuRat (talk) 04:00, 8 October 2017 (UTC)


 * An actual reference:
 * — 2606:A000:4C0C:E200:CCE8:62C2:FF45:AE7B (talk) 05:46, 8 October 2017 (UTC)

Skin moisturizer as universal solvent ?
The first 4 ingredients in my skin moisturizer are water, mineral oil, stearic acid, and cetyl alcohol. So, it should dissolve substances which are water-soluble, oil-soluble, acid-soluble, and alcohol-soluble, right ? Is there some reason this is an important attribute in a skin moisturizer, or is this just a coincidence ? StuRat (talk) 14:29, 6 October 2017 (UTC)


 * Err yes & no. These are just the ingredients for making a Cream (pharmaceutical) which can be washed off. If you have a liquidizer in the kitchen you can make your own – and even eat what's left over. The important omega 3 fatty acids are left out of commercial products as they go rancid quickly and start to smell off. Aspro (talk) 15:37, 6 October 2017 (UTC)


 * That article says that water and oil are essential ingredients, and certainly for a moisturizer the goal is to add water to the skin, and oil is needed to hold it in and prevent immediate evaporation. That article also says an emulsifier and thickening agent are needed.  Do the acid and alcohol serve those purposes ?  If not, what do they do ? StuRat (talk) 16:38, 6 October 2017 (UTC)
 * From the stearic acid article: its primary use is as a "surfactant and softening agent" SemanticMantis (talk) 17:33, 6 October 2017 (UTC)


 * As I understand it oil & water are necessary to make a cream rather than a greasy ointment. The 'goal' of the moisturizer which one buys, is to generate profits for the share holders of the company. Any water can only affect the upper lays of the skin File:Skinlayers.png; like if one stays in the bath too long and ones fingers turn white and fingerprints expand, unlike bathing in sea water. No moisturizer on Earth will reach down to the lower layer where wrinkles form. Proprietary products use emulsifiers in order to combine oil & water (like egg yolks are used to combine the fat of dairy cream to make ice-cream and mayonnaise etc). See a dermatologist, for to find out what skin-care (note: I did not say treatment)suits your skin. If he says you have very thick skin – just point out to him, that as a WP editor -it is a necessity ;-) Aspro (talk) 17:54, 6 October 2017 (UTC)


 * I'm not looking for any medical advice, I only use skin moisturizer on my dry feet. Just wondered why it seems important for a it to be able to dissolve everything. StuRat (talk) 22:11, 6 October 2017 (UTC)


 * As an aside: Do you wear 'real' leather shoes and sandals? They (I assume) made the skin of my feet very thick around the edged of the heal. Assume it was the chromium tanning compounds leeching out and tanning my skin, stopping it flaking of in the normal way until they cracked and became sore. Found that with no leather no problem. Spanish leather riding boot etc' from Argentina don't seem to cause this effect. Maybe this is due to a different tanning process but anyway this all anecdotal. Aspro (talk) 20:51, 7 October 2017 (UTC)


 * No leather footwear, no. My issue is a poorly insulated home which therefore has dry air in winter, causing my lips and feet to dry out.  This results in chapped lips and cracked skin on the bottom of my feet.  I've tried humidifying the air, but it just condenses on the poorly insulated walls and windows and grows mold.  Lip balm on my lips and skin moisturizer on the feet seem to solve the problem. StuRat (talk) 01:00, 8 October 2017 (UTC)


 * I know I shouldn't give medical advice and all that, so don't take it that way, but I'm inclined to mention that after having resorted to various not very effective though not entirely useless tactics like slathering the cracks in neosporin or trimming them down with a steak knife, I became convinced that when humidity is low enough there is no good way to avoid resorting to socks to hold the moisture in, at least for part of the day/night. Chapped lips are something I'm inclined to blame on anything but humidity; it never hurts to ensure riboflavin intake is up to standards. Wnt (talk) 13:42, 8 October 2017 (UTC)


 * I only get chronic chapped lips in low humidity, so I'm sure that's the problem, although salty food does seem to have the ability to suck the water out of my lips, too. The "dehydration" item listed isn't entirely wrong, as the lips are dehydrated, but not my body as a whole.  Skin moisturizer doesn't entirely fix the dry skin on my feet, but does keep it from becoming severe.  I'm sure applying it more often would solve the problem, but the issue is that I can only apply it before going to bed, as otherwise it would get all over my socks, shoes, etc., and make a mess (it does get on my sheets, but I can live with that).  StuRat (talk) 16:57, 8 October 2017 (UTC)


 * To be clear, "acid-soluble" isn't really a thing. The long hydrophobic regions of stearic acid and cetyl alcohol help make them useful as emulsifiers.  So you have water and oil (mineral oil, so don't eat it) kept in some kind of creamy suspension.  Either water or oil can make skin feel wetter, and together they allow a broader range of hydrophilic and hydrophobic compounds to be dissolved in the cream.
 * In concept, a chemical put on the skin can work its way all the way down to the bone (hydrofluoric acid) so there is certainly nothing innately impossible about making an effective wrinkle cream. (If you happen to invent one, do tell us...) Wnt (talk) 12:09, 7 October 2017 (UTC)


 * Cure for wrinkles: Gain weight as they would form, to fill the wrinkles in with fat. (The wrinkles would eventually show anyway, but hopefully you will die from obesity before this happens.) StuRat (talk) 03:13, 8 October 2017 (UTC)


 * See also here. Count Iblis (talk) 03:00, 8 October 2017 (UTC)

Conductive fingernail decoration strip?
Is the metallic form of this nail strip (for decorating fingernails) liable to be conductive or is that a stupid thing to hope? I find myself in need of a conductive material that is adhesive, very narrow (~ 1mm) and aesthetically pleasing/decorative and it would be great if this was, even if the resistance is high for a conductor. --185.216.49.78 (talk) 17:01, 6 October 2017 (UTC)


 * Have you tried the fingernail tips for touch-screens? 209.149.113.5 (talk) 17:16, 6 October 2017 (UTC)


 * They also make gloves with those built in. I own a pair. StuRat (talk) 17:20, 6 October 2017 (UTC)
 * Very high impedance. Too high to power LEDs etc. Andy Dingley (talk) 17:24, 6 October 2017 (UTC)


 * No, it's a plastic (often polyester) with an aluminium metallisation deposited onto it. As the metallisation is so thin, resistance is high.
 * You might find conductive thread to be more useful. Also kitchen aluminium foil can be used like this, so long as you glue it down. I usually stick it to double sided tape, with the backing tape still in place, then guillotine that into narrow strips. Copper is better than aluminium for some tasks, as the oxide layer is less troublesome. Andy Dingley (talk) 17:24, 6 October 2017 (UTC)


 * It's not impossible that it's conductive enough for your purpose. But I wouldn't bet on it. I suppose for 0.99 you don't have much to lose, except your time, but I think you'll be frustrated.
 * Alternatives are conductive ink, copper tape, or conductive thread.
 * Good luck with your project. ApLundell (talk) 18:01, 6 October 2017 (UTC)


 * Carbon fibre is good for this though hard to find. I was given threads from a place selling fibreglass etc. for boat repairs.Polypipe Wrangler (talk) 23:14, 6 October 2017 (UTC)

Salmon
What would happen if a person ate only Salmon every day? Could they survive on that and for how long? — Preceding unsigned comment added by 2408:802A:9700:5083:A0A4:B4BE:DED0:D63F (talk) 18:15, 6 October 2017 (UTC)


 * Till they run out of salmon? ←Baseball Bugs What's up, Doc? carrots→ 18:44, 6 October 2017 (UTC)


 * Conducting such an experiment would be unethical, and you haven't even told us if they are drinking water. See dehydration and ketoacidosis and ask us if you have a question answerable by references, not guesses. μηδείς (talk) 18:53, 6 October 2017 (UTC)


 * Salmon seems quite low in many common vitamins, and in manganese and calcium: . Scurvy and rickets are two possibilities. StuRat (talk) 23:47, 6 October 2017 (UTC)


 * I do not believe an exclusive salmon died would result in scurvy. Salmon has indeed vitamin C.Hofhof (talk) 10:54, 7 October 2017 (UTC)


 * My source (linked above) says it's not a significant source of vitamin C. Do you have another which contradicts this ? StuRat (talk) 00:54, 8 October 2017 (UTC)


 * @StuRat: We need between 65 and 90 mg/day according to Mayo Clinic. According to salmon, it has 7 mg/100 gr. That would require eating 1 kg of salmon/day. If that's the only thing you got, hardly difficult to accomplish. Hofhof (talk) 11:50, 9 October 2017 (UTC)


 * I don't see that 7 mg/100 gr statement there or in the more detailed salmon as food article. Can you give me the exact quote and location ?  We seem to be seeing different versions of that page, for some reason. StuRat (talk) 12:52, 9 October 2017 (UTC)


 * Sorry, I stand corrected. Google led me to believe that the table it was showing me (with the 7.7 mg/100 gr) were from Wikipedia. It was not. Indeed, the best source about vitamin C in salmon that I could find is . Actually it's 0.0.--Hofhof (talk) 20:41, 9 October 2017 (UTC)


 * Another concern could be heavy metal accumulation (i.e. mercury) which is in higher quantity in large fish and in aquaculture-grown fish. — Paleo  Neonate  – 06:05, 7 October 2017 (UTC)

Wasn't there another recent speculative question about what would happen if someone tried to live on one specific food? And what was done with it, if anything? ←Baseball Bugs What's up, Doc? carrots→ 06:22, 7 October 2017 (UTC)


 * The question was closed too soon. Articles like rabbit starvation, No-carbohydrate diet or Inuit diet are about a similar issue. It's a fine question to me to ask what would happen if a human doesn't get enough of this or that nutrient.Hofhof (talk) 10:54, 7 October 2017 (UTC)
 * It was written by a drive-by, so it's unlikely he would even know if it was deleted. ←Baseball Bugs What's up, Doc? carrots→ 20:12, 7 October 2017 (UTC)

Those human-looking robots
You know each year they have those AI things where people make robots that are like people? Last I saw, they just stare off into space but talk like people. Can they now detect eyes and make eye contact and follow your eyes around? That would be well-spooky. Anna Frodesiak (talk) 23:59, 6 October 2017 (UTC)


 * This is nearly ten years ago https://www.youtube.com/watch?feature=player_embedded&v=hCsEFaInYlQ
 * For serious research, look at 'Kismet' at MIT Andy Dingley (talk) 00:07, 7 October 2017 (UTC)


 * Darn. YouTube is blocked in China. :( Would that have show the eyes thing? Anna Frodesiak (talk) 00:16, 7 October 2017 (UTC)
 * http://jarkman.co.uk/catalog/robots/theeyestheeyes.htm
 * http://www.jarkman.co.uk/catalog/robots/giantstaringeye.htm
 * Andy Dingley (talk) 00:43, 7 October 2017 (UTC)
 * That's a good start. Anna Frodesiak (talk) 00:56, 7 October 2017 (UTC)
 * This certainly is doable. We have other technologies that tracks eye movements to determine what the user wants.  See eye tracking.  The more subtle part would be in getting it to know when not to track eyes.  For example, if I hand you a file and say "Here's the Johnson report" and you keep looking at my eyes instead of the report, I'd think there was something wrong with you.  And then there's people on the autism spectrum, who often don't like people staring them in the eyes.  This would upset them, especially if it wouldn't stop, when asked to do so.  StuRat (talk) 00:25, 7 October 2017 (UTC)


 * That makes sense. Maybe it could track the nearest person, or the one emitting the most sound (the one talking). And that "Here's the Johnson report" thing reminds me of someone. Maybe he's a robot. I'm going to pour water on him to find out. :) Anna Frodesiak (talk) 00:31, 7 October 2017 (UTC)


 * Good thinking. That will also work if he's the Wicked Witch of the West, in disguise. :-) StuRat (talk) 00:36, 7 October 2017 (UTC)


 * Or one of those aliens from Signs (film). In fact, I think we should hire a hit man with a Super Soaker (we really do have an article on everything, don't we?) to hose down the top management of the WMF and see if they melt. You can't be too careful. --Guy Macon (talk) 01:24, 7 October 2017 (UTC)


 * Yes, water-soluble evil aliens without the sense to wear raincoats, on a planet where it rains regularly, really gave me a good laugh. StuRat (talk) 01:45, 7 October 2017 (UTC)


 * Someone programmed the computer to generate an opponent Mel Gibson could defeat. Wnt (talk) 21:06, 9 October 2017 (UTC)


 * There was an episode of the original Outer Limits, named Specimen: Unknown, also with threatening water-soluble aliens, but the writers had the sense to make those aliens something closer to fungi, so their stupidity at not wearing proper rain gear can be excused, in their case. StuRat (talk) 23:13, 9 October 2017 (UTC)


 * There could be multiple people talking. Also, whether they are looking at you should figure into whether you look at them, and also how well you know them, should.  Then there are some cultures where servants aren't supposed to look their "masters" in the eyes, which would be important to know, if those robots are to be servants. StuRat (talk) 00:39, 7 October 2017 (UTC)


 * Well, for now, if it just stared at the nearest/loudest that would be pretty impressive, I think. Anna Frodesiak (talk) 00:55, 7 October 2017 (UTC)


 * Not just the loudest, that would mean always looking at Trump. :-) StuRat (talk) 01:49, 7 October 2017 (UTC)


 * Robots that Show Emotion is a relevant TED talk, as are the others on this play list .--Wikimedes (talk) 03:21, 8 October 2017 (UTC)

Thank you, all. :) Anna Frodesiak (talk) 23:06, 9 October 2017 (UTC)