Million Year Old Black Hole Collisions Can Be Identified Using New Cardiff University Model

A theoretical model developed by Cardiff University researchers is expected to help astronomers detect black holes anywhere in the universe, as well as black hole collisions that happened a million years ago.

When used with an updated model of an equipment to detect gravitational ripples across space, the model should be able to pick signals right from the Big Bang to any black hole in the universe. According to the cosmological theory, time began with the Big Bang and ends in black holes.

The equipment called LIGO, or a Laser Interferometer Gravitational-Wave Observatory, makes use of laser beams and mirrors across a vacuum system four kilometres long to detect the waves emitted by accelerating masses.

The experiment began in 2002 but did not find anything till 2010 when the search was halted. When switched on next year with more sensitive meters, researchers should have better luck armed with the Cardiff theory.

Gravitational waves are emitted by any accelerating mass and when it comes to mass, nothing can beat a black hole.

Black holes spin very fast causing their orbits to wobble like a top before it falls over. By studying Einstein's equations for their movements before and after a collision, the scientists are hoping to predict their behaviour.

Dr Mark Hannam from the Cardiff School of Physics and Astronomy says, "The rapid spinning of black holes will cause the orbits to wobble, just like the last wobbles of a spinning top before it falls over. These wobbles can make the black holes trace out wild paths around each other, leading to extremely complicated gravitational-wave signals. Our model aims to predict this behaviour and help scientists find the signals in the detector data."

A merger of black holes is even more complex and has been likened to a waltz that turns into a desperate embrace and final merger. Towards the end of the dance, the two massive objects are hurling gravitational waves into space.

How their spins behave as the black holes collide is something the Cardiff scientists are hoping to simulate.

But understanding the behaviour of the complicated systems will need many simulations of various black hole masses and spin directions.

Despite some claims of detection, gravitational waves have been difficult to detect as they interact very weakly with matter. Some scientists even suspect that stars vibrating at the same frequency as the waves passing through them can absorb the energy of the waves.