On February 11 2016, the LIGO collaboration announced the first direct detection of gravitational waves and the first observaton of binary black holes. Accurate theoretical models of the signal were needed to find it and, more importantly, to decode the signal to work out what the source was. These models rely on large numbers of numerial solutions of Einstein’s equations for the last orbits and merger of two black holes, for a variety of binary configurations. The DiRAC Data Centric system, COSMA5, was used by researchers at Cardiff University to perform these simuations. With these results, along with international collaborators, they constructed the generic-binary model that was used to measure the masses of the two black holes that were detected, the mass of the final black hole, and to glean some basic information about how fast the black holes were spinning. Their model was crucial in measuring the properties of the gravitational-wave signal, and The DiRAC Data Centric system COSMA5 was crucial in producing that model. More information on the detection of gravitational waves can be found at the LIGO collaboration website.

In the figure to the right, the top plot shows the signal of gravitational waves detected by the LIGO observatory located in Hanford, USA whist the middle plot shows the waveforms predicted by general relativity. The X-axis plots time and the Y-axis plots the strain, which is the fractional amount by which distances are distorted by the passing gravitational wave. The bottom plot shows the LIGO data matches the predications very closely. (Adapted from Fig. 1 in Physics Review Letters 116, 061102 (2016))