Two black holes merged billions of years ago
- Posted By
Science & Technology
5th Sep, 2020
- Billions of years ago, a collision between two black holes sent gravitational waves rippling through the universe.
- The signal detected at LIGO and Virgo resembled “about four short wiggles” and lasted less than one-tenth of a second.
- Analysis suggested that GW190521 had most likely been generated by a merger of two black holes.
- It was calculated to have come from roughly 17 billion light years away, and from a time when the universe was about half its age.
- In the merger leading to the GW190521 signal, the larger black hole was of 85 solar masses.
- It is the first “intermediate mass” black hole ever observed.
- Merger creates a new black hole of about 142 solar masses. Energy equivalent to eight solar masses was released in the form of gravitational waves, leading to the strongest ever wave detected.
- Gravitational waves are invisible ripples that form when a star explodes in a supernova; when two big stars orbit each other; and when two black holes merge.
- Travelling at the speed of light, gravitational waves squeeze and stretch anything in their path.
- Gravitational waves were proposed by Albert Einstein in his General Theory of Relativity over a century ago.