A Universe that expands and cools today, like ours does, must have been hotter and denser in the past. Initially, the Big Bang was regarded as the singularity from which this ultimate, hot, dense state emerged. But we know better today. Image credit: NASA / GSFC.

The Big Bang Wasn’t The Beginning, After All

Why you can’t extrapolate back to a singularity.

“Despite its name, the big bang theory is not really a theory of a bang at all. It is really only a theory of the aftermath of a bang.” -Alan Guth

The Universe began not with a whimper, but with a bang! At least, that’s what you’re commonly told: the Universe and everything in it…




The Universe is out there, waiting for you to discover it.

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Ethan Siegel

Ethan Siegel

The Universe is: Expanding, cooling, and dark. It starts with a bang! #Cosmology Science writer, astrophysicist, science communicator & NASA columnist.

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