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galaxies

Andrea Ghez in Hawaii
Q&A

Black-Hole Hunter Takes Aim at Einstein

The astrophysicist Andrea Ghez spent two decades proving that a supermassive black hole anchors the center of the Milky Way galaxy. Her new plan? Test what happens when things get too close.

Andromeda galaxy
Abstractions blog

How Superfluid Dark Matter Mimics an Old Idea About Gravity

Does the force of gravity change at large scales? Perhaps not, but a new theory of dark matter shows why that could appear to be the case.