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July 20, 2022

Shedding New Light on Dark Matter

Planets, interstellar gas, and stars that illuminate the night sky account for only 15% of the matter in the universe. So, how important is a "Cosmological Signature" and what is "Cosmic Microwave Background?" What does either have to do with scientists' search for invisible, dark matter, 85% of the universe, created in the wake of the "Big Bang?" Learn more on NSF's "The Discovery Files."

Credit: National Science Foundation

Shedding New Light on Dark Matter

This is The Discovery Files, from the U.S. National Science Foundation.

Planets, interstellar gas, and stars that illuminate the night sky account for only 15% of the matter in the universe. The remaining 85% is known as dark matter, which emits no light, only detected by the gravitational pull it has on other visible objects.

Dark matter affects how elements like helium, hydrogen, and lithium are formed. But if you can't see it, how can you predict and identify its elusive signature?

Supported in part by NSF, physicists at New York University and Princeton are in fact predicting "cosmological signatures" of dark matter by studying how lightweight forms of elements such as helium, hydrogen, and lithium were created in the immediate aftermath of the "Big Bang."

They are also studying the effects of dark matter on "cosmic microwave background," the electromagnetic radiation created by the union of electrons and nuclei in the wake of the "Big Bang."

The research revealed that lighter forms of dark matter could make the universe expand so fast lightweight elements wouldn't have a chance to form and if certain models of dark matter have a mass that's too small, the universe would look different from what we now observe.

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