Dark Flow

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Previous Episode:

The Secrets of Feynman Diagrams

Space is not static. Everything moves. Planets orbit stars, stars orbit within galaxies, galaxies whirl within the gravitational fields of giant clusters. And of course, the universe is expanding; distant galaxies are thrust apart from each other as the space between them grows. But there’s no preferred direction to any of this motion. Motion due to the expansion of the universe – what we call the Hubble flow – is equal in all directions. The random motion of galaxies – what we call their peculiar motion – should also have no preferred direction. On the largest scales of the universe, there should be no preference for up or down or left or right. At least that’s what we thought. Observations of the cosmic microwave background suggest that the galaxy clusters across the cosmos may be moving, ever so slightly, towards the same point beyond the cosmic horizon. We call this dark flow.

Written and Hosted by Matt O’Dowd

Produced by Rusty Ward

Graphics by Kurt Ross

Assistant Editing and Sound Design by Mike Petrow

Made by Kornhaber Brown (www.kornhaberbrown.com)

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