Nanowerk News By Ilya Mandel 8/23/2017
A tiny disturbance in space became an enormous scientific discovery when LIGO amazingly managed to register it early on the morning of September 14, 2015. This was the first ever observation of a “gravitational wave” – a minute ripple in the structure of spacetime itself – predicted by Albert Einstein a century ago. The signal came from two black holes merging more than a billion light years away, and reached our planet on that very morning.
The detection ushered in a whole new era of astronomy. Two more detections followed (and a third likely one), all from mergers of pairs of black holes. Already, these measurements are starting to help scientists unravel some of the universe’s best-kept secrets. Our new study, published in Nature ("Distinguishing spin-aligned and isotropic black hole populations with gravitational waves"), shows just how close we are to working out how pairs of black holes form.
The black holes studied by LIGO – each weighing in at between 10 and 30 times the mass of the sun – collide while moving at half the speed of light, twisting space and time as they do so. The merger of two black holes releases more energy in a fraction of a second than all of the stars in the visible universe combined.
However, by the time the spacetime distortions, travelling at the speed of light for more than a billion years, get to the Earth, the ripples are very weak indeed – stretching and squeezing space by less than one part in 1021. That means they make the mirrors in the LIGO detector move by less than a thousandth of the size of an atomic nucleus. No wonder gravitational waves have been so hard to detect.
More:
http://www.nanowerk.com/news2/space/newsid=47823.php
