How Big is the Universe? Science of Space. Why we think there’s a Multiverse, not just our Universe. “Every true, eternal problem is an equally true, eternal fault; every answer an atonement, every realisation an improvement.” -Otto Weininger 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. 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. Image credit: NASA, ESA, and J. And when you have a Universe dominated by matter, here’s how it expands. Is There Intelligent Life in The Universe? (Columbia University, 2006) Our small world.