The Universe looks roughly the same in all directions, but distant galaxies appear younger and less evolved than nearer ones. Image credit: NASA, ESA, R. Windhorst, S. Cohen, M. Mechtley, and M. Rutkowski (Arizona State University, Tempe), R. O'Connell (University of Virginia), P. McCarthy (Carnegie Observatories), N. Hathi (University of California, Riverside), R. Ryan (University of California, Davis), H. Yan (Ohio State University), and A. Koekemoer (Space Telescope Science Institute).
“I want to stand as close to the edge as I can without going over. Out on the edge you see all the kinds of things you can’t see from the center.” -Kurt Vonnegut
We all know how explosions work: a tremendous release of energy causes a rapid outward expansion, and the most energetic particles get flung the farthest and at the greatest speeds. Things fly apart, spread out, and wind up a tremendous distance away. And within our Universe, nothing has ever released more energy than the event that started it all: the Big Bang.
An explosion in space would have the outermost material move away the fastest, which means it would get less dense, would lose energy the fastest, and would display different properties the farther away you went from the center. It would also need to expand into something, rather than stretching space itself. Our Universe doesn’t support this. Image credit: ESO.
But the Big Bang itself wasn’t an explosion, even if we commonly think of it that way. Explosions have a center, and while there are explosions in the Universe that do display a center, the Big Bang itself wasn’t one. Instead, we need to take on the proper perspective if we want to understand how this all works, and expand not just the fabric of space, but also our minds.
Artist’s logarithmic scale conception of the observable universe. Image credit: Wikipedia user Pablo Carlos Budassi.
Take a journey back to the very beginning and better understand how we got to be here today, as we take on the center-of-the-Universe question for Ask Ethan!