begood Posted October 29, 2011 Report Posted October 29, 2011 (edited) The best measurements of the distant Universe -- out beyond our galaxy -- have led us to the current picture of exactly what our Universe is doing: expanding and cooling, with its galaxies progressively getting farther and farther apart. (Image credit: Molly Read for the University of Wisconsin-Madison.) But what does that mean for our past? If we're expanding and cooling, that means our past was less expanded and less cooled, or as we like to think of it, denser and hotter. Now, if you're thinking like a scientist, you don't just want to know what it's doing. You also want to know -- if it's expanding -- both what's causing the expansion, and by how much it's expanding. In other words, we'd like to determine the rate of expansion. And the answer is actually straightforward: if general relativity is your theory of gravity, the Universe's expansion rate is determined by what type of energy dominates your Universe. READ IT : Why we think there's a Multiverse, not just our Universe : Starts With A Bang Edited October 29, 2011 by begood 2 Quote