What are gravitational waves? The science behind the winners of the Nobel Prize in physics
The Nobel prize for physics has been awarded to three scientists who were the first to observe gravitational waves.
The waves were predicted by Albert Einstein as part of his theory of general relativity but their existence was confirmed by the Nobel Laureate team using giant lasers.
Winners Rainer Weiss, Barry C Barish and Kip S Thorne, were three of the thousand-plus researchers who worked on the project.
And you might recognise the name Kip Thorne.
Married to a film producer, he heavily consulted on the film Interstellar, and his own calculations helped the special effects team create realistic visuals of black holes.
What are gravitational waves?
Einstein put forward the theory that gravity wasn’t simply a force, pulling an apple to the ground, but that the space around it is like fabric.
A knock to the fabric will cause waves to flow down it, sort of like when you’re trying to fold a bed sheet with someone and you shake it to try and knock it out of their hands.
Gravitational waves are like a wave in the fabric that seems to slightly stretch the space around it.
How did the Nobel laureates detect them?
The team built lasers in North America that travel down something called an interferometer.
Detectors at the end of the lasers’ 8km journey sense whether the path of the laser has varied by minuscule distances (we’re talking subatomic particle level here).
If gravitational waves are at play, the laser light will have travelled a slightly different distance and that variation is detected.
The detector, which they’ve been working on since the 70s, is particularly impressive since it isn’t affected by the background noises of the universe.
Why is their discovery important?
These scientists were able to confirm a lot of what we thought we know about the universe.
They used their results to detect gravitational waves that indicated two black holes were colliding a billion light years away.
And now, as well as using visible light, infrared and radio waves to observe the universe, astrologists could start trying to detect gravitational waves, too.
That black hole crash was relatively small and extremely far away – so imagine what scientists might start “seeing” in the universe with these kinds of tools?