What Are Cosmic Voids? The Biggest Nothings in the Universe HD
We talked about the biggest structures in the Universe, but what about the opposite? The biggest empty spaces in the Universe, the cosmic voids that separate the clusters of galaxies. Check out our interview with Paul M. Sutter, a specialist on cosmic voids: http://www.astronomycast.com/2015/10/ep-389-roundtable-with-paul-sutter/ Support us at: http://www.patreon.com/universetoday More stories at: http://www.universetoday.com/ Follow us on Twitter: @universetoday Follow us on Tumblr: http://universetoday.tumblr.com/ Like us on Facebook: https://www.facebook.com/universetoday Google+ - https://plus.google.com/+universetoday/ Instagram - http://instagram.com/universetoday Team: Fraser Cain - @fcain / frasercain@gmail.com Jason Harmer - @jasoncharmer Chad Weber - weber.chad@gmail.com Created by: Fraser Cain and Jason Harmer Edited by: Chad Weber Music: Left Spine Down - “X-Ray” https://www.youtube.com/watch?v=4tcoZNrSveE Clearly I need to learn to be more specific when I do these episodes. Everything time I open my mouth, I need to prepare for the collective imagination of the viewers. We did a whole video about the biggest things in the Universe, and identified superclusters of galaxies as the best candidate. Well, the part of superclusters actually gravitationally bound enough to eventually merge together in the future. But you had other ideas, including dark energy, or the Universe itself as the biggest thing. Even love? Aww. One intriguing suggestion, though, is the idea of the vast cosmic voids between galaxies. Hmm, is the absence of something a thing? Whoa, time to go to art school and talk about negative space. Ah well, who cares? It’s a super interesting topic, so let’s go ahead and talk about voids. When most people imagine the expansion of the Universe after the Big Bang, they probably envision an equally spaced smattering of galaxies zipping away from one another. And that’s pretty accurate at the smallest scales. But at the largest scales, like when you can see billions of light-years in a cube that fits on your computer screen, then a larger structure starts to take shape. It looks less like an explosion, and more like a tasty tasty sponge cake, with huge filaments, walls, and the vast gaps in between. The gaps, the voids, the supervoids, are the point of today’s video, but to understand the gaps, we’ve got to understand why the Universe is clumped up the way it is. Run the Universe clock backwards, all the way to the beginning, to a fraction of a second after the Big Bang. When the entire cosmos was compressed down into a tiny region of superheated plasma. Although it was mostly uniform in density, there were slight variations - quantum fluctuations in spacetime itself. And as the Universe expanded, those differences were magnified. What started out as tiny differences in the density of matter at the smallest scale, turned into regions of higher and lower density of matter in the Universe. Here we are, 13.8 billion ye
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