Ask Ethan #84: Where did light first come from?

Ethan Siegel
Apr 17, 2015 · 7 min read
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Image credit: Physics Today Collection/AIP/SPL.
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Image credit: the Cosmic Microwave Background of Penzias and Wilson, via http://astro.kizix.org/decouverte-du-17-mars-2014-sur-le-big-bang-decryptage/.
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Images credit: Wikimedia Commons user Sch, under c.c.-by-s.a-3.0 (L), of the Sun (yellow) vs. a perfect blackbody (grey); COBE/FIRAS, via NASA / JPL-Caltech (R), of the CMB.
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Image credit: P. Noterdaeme, P. Petitjean, R. Srianand, C. Ledoux and S. López, (2011). Astronomy & Astrophysics, 526, L7.
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Image credit: Brookhaven National Laboratory / RHIC, viahttp://www.bnl.gov/rhic/news2/news.asp?a=1403&t=pr.
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Images credit: E. Siegel.
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Image credit: E. Siegel, of how spacetime expands when it’s dominated by Matter, Radiation or energy inherent to space itself.
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Image credit: E. Siegel.
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Image credit: E. Siegel.
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Image credit: ESA and the Planck Collaboration, modified by me for correctness.

Starts With A Bang!

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

Ethan Siegel

Written by

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

Starts With A Bang!

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

Ethan Siegel

Written by

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

Starts With A Bang!

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

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