Wikipedia:Reference desk/Archives/Science/2012 December 8

= December 8 =

The Hoverboard in just roughly 2 years, 1 month - how will Mattel prepare?
Hello.


 * 1) What obstacles must we discover / solve / overcome in order to build a practically-working hoverboard that is affordable enough for everyday, middle-class parents to buy for their children?
 * 2) How likely is it that Mattel / any toy company will develop the Hoverboard in time?
 * 3) Starting on January 1, 2015, Mattel's call center may get barraged by a massive queue of calls asking to order the Hoverboard. How might they deal with the sudden, massive influx of demand for an item that may or may not exist by then? If there is no hoverboard by 1-1-2015, how would Mattel deal with the overwhelming volume of calls asking for an item that hasn't yet been made (in time)?
 * 4) If Hoverboards arrive after all, who might make models intended for adults? --Mount Zynar (talk) 22:23, 7 December 2012 (UTC)


 * They won't. It is a 'replica', it doesn't hover.


 * Please do a little research first, rather than wasting our time with ridiculous questions. AndyTheGrump (talk) 23:25, 7 December 2012 (UTC)


 * I suppose you could make a real hoverboard, of a sort, based on a hovercraft:


 * A) Put a powerful downward fan at the front and back, with a rubber cowl around the bottom. You would stand in the center.


 * B) It could have a remote "dead man switch" the user would hold in his hand, so it would stop if the user let go.


 * C) I'd expect it to be somewhat unstable, so you'd need to balance on it, like a surf board.


 * D) It would be loud. Active noise reduction might help.


 * E) It would use up it's fuel supply quickly, especially if it ran on batteries. If it ran on gasoline or any other flammable fluid, then you'd have fumes to deal with and potential for fires.


 * F) I imagine it without any forward thrust provided. The user could roll downhill or kick off the ground, like with a skateboard.  Leaning forward might also let some air escape out from under the back, and give a slight forward thrust that way.


 * G) Hopefully it would be light enough that it could be carried home when it runs out of charge/fuel. StuRat (talk) 23:32, 7 December 2012 (UTC)

I don't think any fans of 2001: A Space Odyssey complained when they were unable to book a flight on a Pan Am space plane that year. HiLo48 (talk) 00:06, 8 December 2012 (UTC)
 * Probably because there was no Pan Am ticket office to call. But Mattel may still exist. --Mount Zynar (talk) 02:20, 8 December 2012 (UTC)


 * One other point:


 * H) You should put wheels on all 4 corners, to prevent damage from striking the ground, and to allow it to work as a normal skateboard when the fuel/charge is used up. StuRat (talk) 17:57, 8 December 2012 (UTC)

Computer Scientists and Ayn Rand

 * Moved to Reference_desk/Humanities

Syria
Moved to Reference_desk/Humanities. OsmanRF34 (talk) 18:41, 8 December 2012 (UTC)

I blame Luna for low Helium-3 ratios
Isn't it obvious that the lack of Helium-3 on Terra is entirely the fault of Luna?

Earth originally had the same Helium ratio as any other rock in Sol system and then got knocked up to such an extent that she gave birth to the moon. In the resulting mix-mash, all the volatiles escaped. Since then oceans of Hydrogen have fallen from the sky while the Helium-4 was replaced through Alpha-decay. Ergo a Helium-3 deficiency. Hcobb (talk) 16:56, 8 December 2012 (UTC)
 * Keep in mind it's possible to inhale too much of the stuff. ←Baseball Bugs What's up, Doc? carrots→ 18:21, 8 December 2012 (UTC)
 * What question are you asking? AndyTheGrump (talk) 18:22, 8 December 2012 (UTC)


 * Why isn't this mentioned in the article? Hcobb (talk) 21:59, 8 December 2012 (UTC)
 * Where's a valid source supporting your claim? ←Baseball Bugs What's up, Doc? carrots→ 23:25, 8 December 2012 (UTC)

Request for bug identification
My apartment has far too many of these. Can anyone tell me what it is? I assume it will be helpful to say that I live in Cincinnati, Ohio. -FisherQueen (talk · contribs) 18:58, 8 December 2012 (UTC)


 * See Brown marmorated stink bug, and note that the article text says that the banding on the antennae is unique to this species. --Modocc (talk) 19:10, 8 December 2012 (UTC)


 * How did you manage to force the bug to pose for the picture near a penny? OsmanRF34 (talk) 20:09, 8 December 2012 (UTC)
 * Being a stink bug, it was probably attracted to the cent. ←Baseball Bugs What's up, Doc? carrots→ 23:23, 8 December 2012 (UTC)
 * Sometimes, Bugs, you are truly awful. Thank you. --jpgordon:==( o ) 01:16, 9 December 2012 (UTC)
 * Best...ref desk...pun...ever! μηδείς (talk) 03:57, 9 December 2012 (UTC)
 * They are a very common invasive species throughout much of the temperate USA. As they seek warmth in cold weather, they often find their way into houses and outbuildings. When found in late fall, they are very sluggish, and easily posed. SemanticMantis (talk) 04:33, 9 December 2012 (UTC)
 * They're pretty docile; not particularly afraid of people, or gentle swatting towards them, and they don't fly with any apparent intent to avoid obstacles. Easy to move objects near them in my experience. DMacks (talk) 08:30, 9 December 2012 (UTC)
 * They don't pose many problem to humans. Sure, they are a little annoying, but they will not eat your food or furniture, spread disease, or suck your blood. Most of them will quietly die in a corner, and you just clean them up when you sweep. They are mildly attracted to lights, and if they bother you, you can usually easily capture them in a jar, and dispose at your convenience. Because they are stink bugs, they can emit foul odors, but in my experience, they usually don't if you catch them slowly. SemanticMantis (talk) 04:38, 9 December 2012 (UTC)
 * Thank you! The girlfriend was right then; she said stink bug, and I said it couldn't be that, because they don't stink.  I'll continue my strategy of ignoring them, throwing them out the window when I see one, and encouraging the cat to eat them.  -FisherQueen (talk · contribs) 12:42, 9 December 2012 (UTC)


 * I love the critters. They are cute and docile and quite fascinating, really.  They usually fly to my reading lamp, and then just walk around a bit on my end table, until I put them back outside (or the smarter ones go hide and escape my banishment).  Feeding them to a cat however would likely be equally unpleasant for both. μηδείς (talk) 17:25, 9 December 2012 (UTC)


 * Why are they called "stink bugs" if they don't stink? Alansplodge (talk) 22:28, 10 December 2012 (UTC)
 * Some varieties of Pentatomidae can exude a foul smelling chemical when threatened. And, of course, squashing them releases all of it at once. &mdash;  The Hand That Feeds You :Bite 23:42, 12 December 2012 (UTC)

Drugs not working the first time
Why some drugs, like marihuana, don't work for some people the first time they use them? OsmanRF34 (talk) 19:47, 8 December 2012 (UTC)
 * I don't think the answer is really known. It might be that the drugs do work but that on the first exposure people don't realize it because they don't know what changes to look for; or it might be that the first exposure induces some changes in brain chemistry that potentiate the effects of later exposure. Looie496 (talk) 20:40, 8 December 2012 (UTC)
 * Marihuana is very fat soluble and requires a little bit of a build-up in the liver before it will be effective--but everyone I know who's tried it has gotten high the next day on their second joint. I am sure we have some sort of source on drug half-life and so forth that will be relevant to this. μηδείς (talk) 01:26, 9 December 2012 (UTC)
 * Genetics are also a factor -- for example, people who are homozygous for the short version of the D4DR gene appear to be less affected by marijuana and other drugs. 24.23.196.85 (talk) 02:36, 9 December 2012 (UTC)
 * Genetics might be a factor for a drug not working at all, but does genetics make the drug useless the first time we use it but not subsequent times? OsmanRF34 (talk) 18:53, 10 December 2012 (UTC)
 * As pointed out earlier, it's fat soluble. Which means continued use builds up more of the chemical in the body over time. "Less affected" doesn't mean "unaffected," after all. &mdash;  The Hand That Feeds You :Bite 23:46, 12 December 2012 (UTC)
 * You may be interesting in reading reverse tolerance. SemanticMantis (talk) 04:29, 9 December 2012 (UTC)

Sweat drops and electric resistance
If some person grasps and briefly hangs on high-power cable line, what role would sweat or other moisture droplets on his/her hands play? Is their absence crucial to body's electric resistance? --93.174.25.12 (talk) 22:23, 8 December 2012 (UTC)


 * Sweat increases the skin conductance. But if you grasp a high voltage line, it really won't make any difference. Looie496 (talk) 23:28, 8 December 2012 (UTC)


 * But if you hang from the cable (not touching the ground) your body isn't part of an electrical circuit and the resistance won't matter. Sjö (talk) 00:00, 9 December 2012 (UTC)


 * So even if you grasp the line with wet hands and not touching the ground, you wouldn't be affected in any way? 93.174.25.12 (talk) 00:19, 9 December 2012 (UTC)


 * While you should generally avoid grasping high-voltage transmission lines under any circumstances unless you know what you're doing, generally speaking...yes, you can safely grasp a high tension line without harm as long as you're not in contact with (or near) anything else at a different potential (voltage and phase). In situations where power workers need to inspect or maintain live high-voltage transmission lines, they can bond themselves appropriately to the line so that their tools and bodies are at the same potential as the line and no current flows through them.  (See live-line working and Faraday suit.)  This is also why birds can land on high-tension lines without getting fried. TenOfAllTrades(talk) 00:49, 9 December 2012 (UTC)


 * Similarly, squirrels can cross such lines safely - unless they make the mistake of "grounding" themselves when they reach the next pole. Then you get fried squirrel, which may sound gross to us, but is a prized delicacy to your average crow. ←Baseball Bugs What's up, Doc? carrots→ 12:48, 9 December 2012 (UTC)


 * Fried squirrel is a normal way of preparing it. Or stew, barbecued or ground in to sausage. 75.41.109.190 (talk) 18:14, 9 December 2012 (UTC)


 * Mmmm... rodent sausage. ←Baseball Bugs What's up, Doc? carrots→ 02:02, 10 December 2012 (UTC)


 * Them's good eatin'. Coincidentally, I'm currently translating a scientific paper on Glis glis, the Edible Dormouse, which was, and still is to a limited extent, eaten in Europe. It was much prized by the Ancient Romans. By the way, it's off the menu here in Poland, where it is considered a protected species. Dominus Vobisdu (talk) 04:46, 10 December 2012 (UTC)


 * While we're here, and discussing squirrels and 'good eatin', a question for USAians (e.g. Bugs). What is the difference between 'critters' and 'varmints' (if any), and where do squirrels fall within the categories? Dictionaries seem to suggest that 'varmints' = vermin, and as such not 'good eatin' accordingly, but given the evident delight taken in shooting the tufty-tailed skyrats and man-cooking them (i.e. grilling, frying, or roasting with an oxyacetylene torch) taken your side of the pond, are they somehow what anthropologists tend to describe as 'liminal' - neither one thing nor another? If the local butcher (assuming such still exists) had "Fresh Squirrels, $1.40 each" advertised for sale, how would the customers react? AndyTheGrump (talk) 05:31, 10 December 2012 (UTC)


 * Yes, I think varmints are to critters as weeds are to plants. That is, they are unwanted critters, just as weeds are unwanted plants.  And only rednecks eat squirrels in the US. Why do rednecks eat roadkill ? ... Cuz the tire tread pattern makes a great irrigation system for the gravy. StuRat (talk) 06:01, 10 December 2012 (UTC)


 * The word "critters" is derived from "creatures" and "varmint" from "vermin" so the "plants versus weeds" analogy is correct. Roger (talk) 06:06, 10 December 2012 (UTC)


 * I thought "varmint" was synonymous to "throw up" ;) - ¡Ouch! (hurt me / more pain) 11:15, 11 December 2012 (UTC)


 * "Excuse me, I have to go and varmint". Nah, that'll never float.  --   Jack of Oz   [Talk]  11:51, 11 December 2012 (UTC)
 * And not to be confused with the Irish sport called "Hurling". ←Baseball Bugs What's up, Doc? carrots→ 12:59, 11 December 2012 (UTC)
 * I'm in eastern Kentucky, where this is not uncommon. (And we prefer "hillbillies," thankyouverymuch. ;) ) Squirrels have so little meat that it's typically just consumed by the hunter & their family. There's no real business for squirrel meat. You might find someone selling some burgoo at a festival or such, but that's about as close as you'd get to "commercial" squirrel. &mdash;  The Hand That Feeds You :Bite 23:55, 12 December 2012 (UTC)


 * It won't make much difference with a high voltage line, but moist skin plays a large role in electrocution at lower voltages. --Srleffler (talk) 19:31, 11 December 2012 (UTC)

head shave vs bald
Hi, I wonder why when someone shaves his head completely bald with a razor, his scalp becomes gray. I mean the color of the hair isn't gray, so what do we see? I read that bald people have hair at the bald parts, but it is too short to see, so why we don't see gray either at those parts? — Preceding unsigned comment added by 77.126.90.48 (talk) 23:32, 8 December 2012 (UTC)
 * It's because of hair follicles, whose multitude gives a shaved head its dark shade (similar to any shaved area of body), but shaved blonde scalps may have a lighter shade than those of brunettes. Permanent hair removal removes all such traces. Brandmeistertalk  00:13, 9 December 2012 (UTC)
 * If you shave your head with a razor, you're not removing the hairs, you're just cutting them very very short. My sort of baldness, on the other hand, is due to the follicles shrinking (in response to DHT), and what remains is either nothing or tiny tiny little soft, colorless hairs. I don't actually know if those tiny hairs grow, fall out, and are replaced. --jpgordon:==( o ) 01:13, 9 December 2012 (UTC)