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Lede art for "Troubled Times for Alternatives to Einstein’s Theory of Gravity"

Troubled Times for Alternatives to Einstein’s Theory of Gravity

New observations of extreme astrophysical systems have “brutally and pitilessly murdered” attempts to replace Einstein’s general theory of relativity.

Illustration for Extreme Radio Bursts

Astronomers Trace Radio Burst to Extreme Cosmic Neighborhood

A mysterious object that repeatedly bursts with ultra-powerful radio waves must live in an extreme environment — something like the one around a supermassive black hole.

An artist’s view of a pulsar near the center of the Messier 82 galaxy.

Galactic Glow, Thought to Be Dark Matter, Now Hints at Hidden Pulsars

A number of high-energy anomalies raised hopes that astrophysicists had seen their first direct glimpses of dark matter. New studies suggest a different source may be responsible.