Features

Column: Collision detected through space and time


BY NOAH ALESHIRE, CONTRIBUTING WRITER


Have you ever thought about how incredible the universe is and wondered how it could possibly get more amazing? Well, scientists confirmed last week that they have detected gravitational waves from a black hole collision nearly two billion light years away. If this does not sound impressive, here is some information to help you better understand.

A black hole is a region of space-time (space and time intertwined) that has such a strong gravitational pull that nothing, not even light, can escape it. The main force of black holes is their immense gravity, and this gravity can be detected by instruments here on Earth.

Scientists use an underground instrument called a Laser Interferometer Gravitational Wave Observatory (LIGO) to detect gravitational pull. This device sends a laser beam down two tubes, which are each two to four kilometers in length. The laser bounces off a mirror at the end of the tubes and travels back to the source.

Usually, the waves of each laser beam will cancel each other out. However, in the presence of a gravitational wave, the waves of each beam will be misaligned by an incredibly small amount. No matter how small the misalignment is, it’s a detection of a gravitational wave.

On Aug. 14, scientists detected gravitational waves from a black hole collision that occurred 1.8 billion lightyears away from Earth. In theory, gravitational waves travel at the same speed as light, which is the speed limit of the universe. This means it took the gravitational waves 1.8 billion years to travel to Earth and be detected by LIGO. Impressed yet?

The universe is largely unknown, but with instruments like LIGO, we can hope to better understand the forces that make up its expansion.


This article first appeared in the Friday, October 6, 2017, Edition of The Echo.