Wikipedia:Reference desk/Archives/Science/2015 December 27

= December 27 =

Tablet usefulness?
Please don't post the same question twice. See identical question, Reference_desk/Miscellaneous. μηδείς (talk) 01:23, 27 December 2015 (UTC)

virus
If viruses don't eat, where do they get the energy for motion? — Preceding unsigned comment added by Money is tight (talk • contribs) 01:48, 27 December 2015 (UTC)


 * Typically viruses undergo diffusion, which is passive, or move with underlying bodily fluids. It would be possible for viruses to take up energy to move, for example by including a myosin protein and consuming ATP at their surfaces ... I don't know of any actually doing such a thing.  Out in the environment, any sort of deliberate motion would have limited use - it serves no purpose for a virus in a sneezed aerosol droplet to try to swim around inside it, or for a virus dried to a railing to try to drag itself along the surface.  Inside the body ... diffusion and the movement of bodily fluids get them around quite nicely. Wnt (talk) 02:31, 27 December 2015 (UTC)


 * They could also catch a ride in a cell, say a blood cell, and quickly move that way. StuRat (talk) 06:15, 27 December 2015 (UTC)


 * As discussed above, they don't. A virus is, in the words of Peter Medawar, "a piece of bad news wrapped in a protein coat". Viruses outside cells don't do anything. They just sit around until they have a chance encounter with a cell. For this reason, there is a long-running debate over whether viruses should be considered living things. --71.119.131.184 (talk) 08:21, 27 December 2015 (UTC)


 * There is, though Googling suggests that the current thinking is that they are alive. We should probably have a standalone article about the topic, rather than just a single paragraph in virus. 99.235.223.170 (talk) 15:12, 27 December 2015 (UTC)


 * Within a cell viruses very often attach to microfilaments or microtubules to hitch a ride towards the nucleus using the processes used to transport proteins around the cell. The cell provides the energy to move them. Dmcq (talk) 12:49, 27 December 2015 (UTC)


 * Many plant viruses encode movement proteins that help them move around inside their plant hosts, by hijacking plant functions. Also there is one specific type of movement often seen in viruses: many are shaped sort of like a hypodermic needle, and after they have attached themselves to the membrane of a cell, they undergo a conformation change that acts like pressing the plunger of the hypodermic, causing the "payload" (containing the virus's genes) to be injected into the cell. Looie496 (talk) 12:59, 27 December 2015 (UTC)

How fast would Moore's Law be if most surplus productivity was applied to Moore's Law?
I've always wondered this and wouldn't be surprised if it's not that much faster. Sagittarian Milky Way (talk) 19:30, 27 December 2015 (UTC)


 * Just throwing random people at the problem won't help. Since scientific discoveries drive Moore's law, to speed it up you would need to put more electronics scientists and engineers on the problem, have them work more efficiently by sharing info and each have sufficient funds, equipment, staff, etc.  How exactly to get that degree of cooperation among competing scientists in competing companies and competing nations is an open question. StuRat (talk) 19:42, 27 December 2015 (UTC)


 * I know that random people wouldn't help much (though there's probably something they could do, we used to put a lot of our productivity into technical-industrial-mechanical-factory-type things of which less right left-brained people have no interest so it's possible. (Maybe unskilled workers could help with massively low chip yields from pushing Moore's Law too hard by making wasteful amounts of chips and doing things manually that are done with robots in real life). Yes, putting it all into one industry isn't beneficial to society and would require communalism to a level that isn't realistic or good, I just wanted to know how much of the 18 months per double is "what humans could do" and how much is "what humans actually do". There's obviously also a limit on the percentage of humans with the IQ and zone of interest to be electronics scientists and engineers. Also, there's different levels of "most of surplus productivity". Putting what the US did into defense in the Cold War into Moore's Law instead is one thing, putting in what North Korea does with defense is another (only the military has enough food). Sagittarian Milky Way (talk) 22:14, 27 December 2015 (UTC)


 * I've often wondered something similar, in my case how much the exploration of space or achievement of immortality through electronic copies of our brains could be moved up, if we made it a priority. StuRat (talk) 03:53, 28 December 2015 (UTC)


 * Then 2001:A Space Oddessy would be real (minus the supernatural parts and strong AI). Sagittarian Milky Way (talk) 04:03, 28 December 2015 (UTC)


 * This is off-topic, but I can't beat the bait. The problem with "immortality" by copies of the brain is this:  suppose you have a videotape of a woman being tortured.  If you run it in a loop in an empty room, are you causing suffering?  Suppose you have a doll with a pull tab and it screams when you let it go (a Goth girl's toy, perhaps) - are you causing suffering?  We suppose, IMHO correctly, that these electronic effigies don't actually feel anything that a person would feel.  But we have no idea why.  It's all just one pattern or another of electrical impulses, some would say, so what's the difference?  The most rational solution would be to say that people don't feel anything and are just biochemical automatons with complex behavior, but individual people know that is wrong.  We should recognize, therefore, that qualia are a paranormal phenomenon, one which we have no idea of the reasons for (though I have been prone to guess).  It is not immediately obvious that we will ever know how to duplicate it, though I can't rule it out. Wnt (talk) 13:38, 28 December 2015 (UTC)


 * Yes, this problem is discussed in artificial consciousness. StuRat (talk) 15:43, 29 December 2015 (UTC)

How many names could one learn?
First, a little background anecdote. A friend told of an entomologist who refused to be introduced to people if it meant having to learn their names. He was afraid that he might forget beetle name if he learnt a new human name. Looking at the article on Beetles, 400,000 are described. There is a lot of systematics in the naming here here, which helps. Now for the question, which I have not found any clues to in wikipedia. My friend was convinced he could name all 400,000. Question: How many names could he actually have learned? Star Lord -   星爵 (talk) 22:35, 27 December 2015 (UTC)


 * People with very specific disorders are able to memorize considerable quantities of material. Kim Peek, for example, had memorized around 12,000 books.  But relatively normal people such as John von Neumann have demonstrated the ability to perform at similar levels. Swami Vivekananda seemed to have memorized 10 volumes of Encyclopedia Britannica over just a few days.
 * So the mental capacity to store that much information is certainly present in some individuals - and names of beetles ought to be easier than volumes of encyclopedias or other books because it's an organized body of knowledge - you can guess a good chunk of the full latin name of a beetle by knowing enough about it's morphology - so it may only be a matter of remembering the unique features of a particular beetle and associating that with the final part of the name.
 * It's an amazing trick - but definitely not impossible. This is an account of a fairly normal person who set about memorizing two volumes of the yellow-pages phonebook in two weeks - he's a "memory champion" - but he uses techniques that most people can master.
 * So I believe the story - it seems exceptional, but definitely not impossible. SteveBaker (talk) 23:02, 27 December 2015 (UTC)


 * This fellow makes extraordinary claims to impeccable memory, as well as other claims. The article makes for an interesting read. Akld guy (talk) 05:26, 28 December 2015 (UTC)


 * I should have asked my friend whether he could actually identify 400000 beetles, and not just rabble them :). Just listing them from memory would be so very useless for an entomologist :) Star Lord  -   星爵 (talk) 12:25, 28 December 2015 (UTC)


 * The human brain should be able to store about 2.5 petabytes of information and it is not thought that you can fill it up in a lifetime, so learning a new fact shouldn't mean you should forget another one. Richerman    (talk) 23:12, 28 December 2015 (UTC)


 * What happens if immortality is invented? Will we have dudes with severe deja vu who remember their last century and formative era without memory problems but might forget where they lived at age 4274? "6838 AD? Crap, when did I move from Hoth IV to Omega Centauri? It was the 6800s but which decade? I can only name the last 26 Galactic Presidents." Sagittarian Milky Way (talk) 00:30, 29 December 2015 (UTC)
 * We'll drive off that bridge when we come to it. ←Baseball Bugs What's up, Doc? carrots→ 01:08, 29 December 2015 (UTC)
 * We're only a little genetic engineering away. Just copy those species with negligible senescence. Sagittarian Milky Way (talk) 01:53, 29 December 2015 (UTC)
 * Is there any known way to test the memory of a tortoise? Or, for that matter, a bristlecone pine? ←Baseball Bugs What's up, Doc? carrots→ 03:28, 29 December 2015 (UTC)