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Short answers to big questions: Exploring atoms in space

Adam Frank, professor of physics and astronomy. (University photo / J. Adam Fenster)

So yes, space is pretty damn empty.

In a new, regularly occurring feature on NPR, astrophysics professor Adam Frank will answer listener questions about about space, the universe, and everything in between. In this installment, Frank takes on the question, “if there are points in space with only three atoms per cubic meter, what fills in the rest?”

And the short answer: nothing.

Right because essentially for a physicist, the absence of matter is nothing. I mean there is still space and time there, but you know – the absence of matter we consider to be a state of, you know, zero matter, zero energy density.

Portrait of Adam Frank

Astrophysicist Adam Frank

A self-described “evangelist of science,” Frank regularly writes and speaks about subjects like intelligent life forms in the universe, high-energy-density physics, space exploration and missions, climate change, and more.

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