By Danny Brown
Cardiff physics professor, Bernard Schutz, is set to receive the Eddington Medal from the Royal Astronomers Society for an “investigation of outstanding merit in theoretical astrophysics”.
Schutz is being awarded for his 1986 paper which showed how the detection of gravitational waves could be used to determine the Hubble constant to an incredibly high degree of accuracy, a value which is necessary to be able to calculate the age of the universe.
Gravitational waves were a prediction of Albert Einstein’s General theory of relativity, they are created by massive bodies (such as black holes or neutron stars) orbiting each other, spiralling closer and closer until they coalesced. The orbiting bodies create gravitational waves in the fabric of space-time, they were successfully detected in 2015 through the international experiments LIGO and Virgo.
Schutz theorised that through detecting gravitational waves we could measure the distance to the source of the waves, and we could point telescopes in the direction of the galaxy where the waves were originating and measure the speed at which it’s moving away from us. With this combination of knowledge, the expansion rate of the universe can be calculated to an incredibly high degree of accuracy.
The expansion rate of the universe is a “number that astronomers prize, it’s one of the hardest numbers to measure, but we have this new way of doing it now with gravitational waves”. Using Schutz’s method will be able to obtain a value of Hubble’s constant to 3% accuracy.
Schutz’s name will now be listed alongside the previous winners of this medal, such as Stephen Hawking, Roger Penrose and Georges Lemaître.