Gravitational Waves (finally) Detected!

Researchers detected ripples in space-time due to
the merger of two black holes.
Credit: NASA

 Gravitational Waves: Why should we care?

As you may have heard, researchers working together from around the world, have detected gravitational waves, but why is this a big deal?

Well here's five reasons we at the NSO were extremely excited by the recent announcement...

  1. First predicted by Albert Einstein 101 years ago this discovery confirms his famous general theory of relativity. He predicted that gravitational effects were due to the rapid motion of massive objects curving space-time and causing ripples in space-time. These ripples are gravitational waves and are what have been finally detected.
  2. Their detection has been a long time in the waiting! Detectors have been searching for gravitational waves since the 1970s, with many millions of pounds being spent on various unsuccessful projects.
  3. The equipment required to detect the gravitational waves was incredibly accurate. They were able to measure distances not to the millimetre but to a fraction of the width of a proton, one of the particles which makes up an atom's nucleus!
  4. With the detection of gravitational waves comes the discovery of black holes. OK, we have known about black holes for a long time - we can see stars orbiting around them and sometimes material being ejected from them - but due to the fact that their gravitational pull is so strong they do not allow light to escape them, up to now we have not been able to directly observe them. Gravitational waves however, are a signal that is coming directly from the black hole and provides information about them. To this end, we have for the first time observed black holes!
  5. Using gravitational waves will revolutionise astronomy as it gives us a method to directly detect the motion of material, regardless of whether it is emitting light or not. As mentioned above, this has already allowed us to directly 'observe' the existence of black holes but this has the potential to go way beyond that. The hope is that later generations of gravitational wave detectors will be sensitive enough to detect the waves left over from the early stages of the Big Bang! A new era of astronomy has truly dawned.