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Ask Ethan #101: Did The Universe Need To Be Born “Lumpy”? (Synopsis)

By esiegel on August 14, 2015.

“First, you should check out my house. It’s, like, kinda lame, but way less lame than, like, your house.” -Lumpy Space Princess, Adventure Time

When you visualize our Universe today, you probably think about the great clumps of matter -- planets, stars, galaxies and clusters -- separated by huge distances. But on the largest of all scales, tens of billions of light years in diameter, any given region of the Universe is virtually indistinguishable from any other.

Image credit: ESA/Herschel/SPIRE/HerMEs, of the Lockman Hole. Image credit: ESA/Herschel/SPIRE/HerMEs, of the Lockman Hole.

But this structured Universe only came about because our Universe was born with initial fluctuations at the start of the hot Big Bang. Without those fluctuations, would we have formed anything? And do the laws of physics demand that we start with those fluctuations, and if so, could they have been much smaller? And then what?

Image credit: ESO/S. Guisard. Image credit: ESO/S. Guisard.

The answers to all of those questions await you on this week's Ask Ethan!

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ask Ethan
dark energy
Galaxies
gravity

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