Glossary

Gravitational Waves

Gravitational waves are ripples in the fabric of spacetime, produced when massive objects accelerate, predicted by Einstein in 1916 and first detected by LIGO in 2015. The most powerful sources are colliding black holes and neutron stars, whose final merger sends a chirp of waves outward at the speed of light. Detectors measure distortions thousands of times smaller than a proton. Pulsar timing arrays have since revealed a low-frequency background hum thought to come from supermassive black hole pairs across the cosmos.

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Cosmology · Gravitational Waves · Black Holes

The Collision That Came In Sideways

Theory assumed colliding compact objects settle into near-perfect circles before merging. Then astronomers reanalyzed a black hole swallowing a neutro...

August 29, 202612 min read

Astrophysics · Neutron Stars · Nucleosynthesis

Where the Gold Came From

Every gold ring and platinum wire on Earth was forged in a collision so violent it shook spacetime. In 2017, astronomers watched two neutron stars mer...

August 7, 202613 min read

Cosmology · Gravitational Waves · Black Holes

The Census of Colliding Black Holes

In one release, the number of gravitational-wave detections more than doubled. The fourth LIGO-Virgo-KAGRA catalog turned a handful of collisions into...

July 16, 202614 min read

Astrophysics · Black Holes · Gravitational Waves

The Day Two Black Holes Released More Energy Than Every Star in the Observable Universe Combined

On September 14, 2015, LIGO recorded the final 0.2 seconds of a collision that had been a billion years in the making. The peak luminosity exceeded th...

May 25, 202614 min read

Astrophysics · Gravitational Waves · Pulsar Timing

Sixty-Eight Dead Stars Just Detected the Background Hum of the Universe

Earth is bobbing up and down in a sea of gravitational waves that stretches from one end of the cosmos to the other. We have no instrument on Earth bi...

May 24, 202615 min read

Astrophysics · Machine Learning · Survey Astronomy

How AI Is Quietly Rewriting Astronomy, From Gravitational Waves to a New Einstein Ring

The Vera Rubin Observatory will produce 20 terabytes of imaging per night. Astronomy still functions as a science only because it has, very quietly, h...

May 1, 202616 min read