A couple of weeks ago an announcement was made by a consortium of scientists from around the world about the discovery of gravity waves.
“Big deal,” I hear you say while trying valiantly to stifle a yawn.
Well its a big deal about something very small caused by something very big.
The wave was just 0.000000000000000000001m high.
Gravity waves are minute ripples in space-time, the four dimensional fabric of the Universe in which all of nature and history is played out. They were predicted as by Einstein’s General Theory of Relativity in 1915 but took a century to actually detect.
To put things in perspective let’s say a big human is 2m tall and weighs 100kg.
The Earth is 12,000,000m in diameter and weighs 57,000,000,000,000,000,000,000,000kg.
The Sun is 1,392,000,000m in diameter and weighs 1,989,000,000,000,000,000,000,000,000,000kg.
What created the gravity wave pulse was two black holes spiraling into each other under the attraction of their colossal gravity and merging. One weighed 36 times as much as the Sun and the other 29 times. In the process 3 times the mass of the Sun was converted in an instant into the gravity wave pulse. This would have been an awesome spectacle but you would not have wanted to be too close on account of the gravity sucking you in and the gamma rays spewing out from around the collision site.
All this happened 1.3 billion years ago and it took that long at the speed of light to get here. At that time all the land on Earth was concentrated in one big continent called Rodinia. The sea was full of single celled organisms. There would be no multicellular life for another 700 million years. Rodinia would have been completely devoid of even a speck of anything alive.
The gravity wave was detected by what could be described as the biggest tool ever built. There are two sets of L-shaped tubes 4 kilometres long with lasers and mirrors that do the measuring and they are located on opposite sides of the U.S. A third site is to be built in India to add more resolving power to the setup.
For me one point of interest was that the University of Glasgow was involved in the consortium. They were trying to measure gravity waves there in 1970 when I started studying Physics (or as it was rather grandly called, Natural Philosophy). It only seems like 1.3 billion years ago.