"A human is halfway in size between an atom and the known universe"... This is a paraphrased quote I have come across several times. I like it. Who said it first? How true is it in the most literal sense? And, finally, what errors arrive in postulating a universe, or an atom, which can be measured AT ALL from our singular, relativistic, perspective? [more inside]
posted on Feb 18, 2007 - 14 answers

What is anti-matter? [more inside]
posted on Sep 26, 2006 - 14 answers

AskMeFi Physics folk: How do astronomers account for the temporal distinctiveness of their galactic subjects in their calculations? I understand that observations of the red shift of quasars delinates a speed increase in the expansion of the universe - yet my brain explodes when I try to understand how the enormous expanse of time is factored into these models. [more inside]
posted on Apr 9, 2006 - 12 answers

Can anyone recommend any good recent articles or papers on whether the universe is infinite or finite? I've heard that scientists suspect that the universe is flat, which lends credence to the infinite-universe hypothesis. I've decided I don't know enough about this. Nothing too technical, please, though I'd prefer something more complex than an article from a newspaper science section.
posted on Jan 12, 2005 - 20 answers

AskMe physicists: Assuming there were any, where did the entropy from previous universes go? [more inside]
posted on Feb 24, 2004 - 14 answers