Discovery of gravitational waves opens new window on the universe

Christi Cloete -- Tue, 04/26/2016 - 14:34

Discovery of gravitational waves opens new window on the universe

The first direct measurement of gravitational waves captured the imagination of young and old and caused people to realise the greatness and majesty of the creation and the Creator once more.

This is according to Prof Christo Venter of the Centre for Space Physics, who recently gave a public lecture on the discovery of gravitational waves at the Potchefstroom Campus of the North-West University.

He discussed various fundamental concepts, including Newton gravitation, Einstein gravitation, waves, interference and polarisation. He especially emphasised the discovery of gravitational waves on 14 September last year by the Laser Interferometer Gravitational-Wave Observatory (LIGO). “This miniscule signal is the result of two massive black holes fusing, and the signal was isolated from the intrusive signals from the environment through exceptional experimental ingenuity.

“It was such a cataclysmic event that the pink luminance outshone the radiation of all the visible stars in the universe for a moment! However, the sources are so far away from the earth that the signal is only a whisper of the original.”

Venter emphasised various important results of this measurement. In the first place, Einstein’s highly successful theory of general relativity was affirmed once more, which distinguishes it as the best gravitational theory to date, in spite of the existence of various alternative theories.

“This measurement also has important astrophysical implications. Before this, nobody knew for certain whether black holes with masses of approximately 25 times that of the sun could exist and whether they could fuse. LIGO’s measurements are direct proof that it is indeed possible, and also provided details regarding the separate black holes that became one (as well as regarding the area where these sources formed). More generally, gravitational waves open a new window on the universe as it were.

He said that gravitational wave astronomy promises to reveal more of the mysteries of the universe because it is a totally new way in which we can observe the universe’s most cataclysmic processes.

Venter said local scientists involved in the biggest radio telescope in the world, the Square Kilomotre Array (SKA), are also very excited. Two-thirds of this array is already being built in Carnarvon in the Northern Cape. Scientists cannot wait to use this telescope to discover gravitational waves as well (albeit at a different frequency than that of LIGO) with the aid of pulsars or rotating neutron stars.

“The LIGO project was the stimulus for unbelievable technological development over the past number of decades, and it serves as an inspiration for a new generation of physicists who want to study our universe.”

PHOTO: Prof Christo Venter (left), who delivered the lecture, with the dean of the Faculty of Natural Sciences, Prof Kobus Pienaar.