Wikipedia:Reference desk/Archives/Science/2014 March 15

= March 15 =

Mass and space and nothingness
Is it true that space cannot exist without mass? If so, how can it be that the universe formed out of nothing? If there was originally no space and no mass, what came first? Also, if there was nothing at the start, in what space did that nothing exist?--109.144.153.12 (talk) 00:59, 15 March 2014 (UTC)


 * Space exists because there are things in space which define the space. If you have no objects, you have no frame of reference, so you have no space to define.  It isn't mass per se (though all objects have mass, because mass and volume are the two fundamental properties of matter) but the presence of a thing to define dimensions of space.  -- Jayron  32  02:02, 15 March 2014 (UTC)


 * See Massless particle. --   Jack of Oz   [pleasantries]  03:09, 15 March 2014 (UTC)
 * Massless particles are not matter.-- Jayron  32  04:48, 15 March 2014 (UTC)
 * Don't they contain energy, and isn't there an equivalence of matter and energy? --   Jack of Oz   [pleasantries]  07:00, 15 March 2014 (UTC)


 * "Matter" is often defined as any particle with non-zero rest mass, hence because massless particles have zero rest mass, then by definition they are not matter. Dragons flight (talk) 07:15, 15 March 2014 (UTC)
 * There may have been no beginning, only a current universe we are in which may be one of many. Or if time only exists in a universe how can one talk of a time before the universe? Dmcq (talk) 11:48, 15 March 2014 (UTC)


 * Where does the premise: "If there was originally no space and no mass" come from? As far I recall the Big Bang, there was an initial mass and a (small) initial space. Star Lord -   星王 (talk) 14:54, 15 March 2014 (UTC)
 * There may have been a lot of energy around at the time, but not mass I suggest. Of course later on some of the energy was converted to mass.--31.55.104.196 (talk) 00:34, 16 March 2014 (UTC)
 * Right you are. Star Lord -   星王 (talk) 11:33, 17 March 2014 (UTC)


 * This is a difficult question. Our article on Mach's principle does a pretty good job of explaining the issues and the way various people have thought about them. Looie496 (talk) 15:58, 15 March 2014 (UTC)


 * Maybe there was no start, to start with. OsmanRF34 (talk) 20:14, 15 March 2014 (UTC)


 * Is it true that space cannot exist without mass?
 * Definitely not. See vacuum, which is space without mass.
 * If so, how can it be that the universe formed out of nothing?
 * We don't know that the universe formed out of nothing, and no reputable scientist would claim it did.
 * If there was originally no space and no mass, what came first? Also, if there was nothing at the start, in what space did that nothing exist?
 * Again, we have no evidence that the universe formed out of nothing, or that there was originally no space and no mass. --Bowlhover (talk) 20:59, 15 March 2014 (UTC)

Coffee to help you sleep?
My mum sometimes has trouble getting to sleep. Am I right in thinking you could leverage caffeine to make sleep easier by drinking coffee in the morning so that in its absence in the evening you'd be more tired? --78.148.110.69 (talk) 02:30, 15 March 2014 (UTC)
 * I'm afraid we cannot offer medical advice, including therapies for sleep problems. You're going to have to tell your mum to seek the advice of a professional directly.  -- Jayron  32  02:32, 15 March 2014 (UTC)


 * Lame. I'm gonna get her to try my coffee idea. --78.148.110.69 (talk) 02:38, 15 March 2014 (UTC)
 * Sorry, but "lame" is not a reason to break ITN policy. μηδείς (talk) 02:58, 15 March 2014 (UTC)


 * I think it is a fact that caffeine is a stimulant. Draw your own conclusion.--31.55.104.196 (talk) 00:28, 16 March 2014 (UTC)
 * Yes, that's why Modafinil is usually prescribed. Count Iblis (talk) 02:24, 16 March 2014 (UTC)