In a world where the media reports an awful lot of stories of despair and doom, I often take solace in science news. I find that stories in science are frequently the most positive – reports of amazing new discoveries, life-changing inventions, cures for terrible diseases and so on. On February 11th 2016 science proved yet again to be a ray of light in an otherwise gloomy world of news, with the announcement from the Ligo Collaboration that gravitational waves have been observed for the first time from the collision of two black holes over a billion light years away.
As this excellent video by Caltec explains, the event of the black holes colliding is pretty exciting in itself. They in fact collided about 1.3 billion years ago, and it’s taken this long for the effects to reach us because they are so far away. At the moment the black holes collided and merged, for a fraction of a second they released a gravitational wave 50 times more powerful than that of all the stars in the Universe combined. The gravitational wave then travelled at the speed of light across the Universe, and eons and eons later it at last reached Earth where humans had finally created the technology in order to observe them: The interferometers at the Ligo facilities in the US. As executive director of the Ligo project Prof David Reitze so eloquently put it, “It’s the first time the Universe has spoken to us through gravitational waves. Up until now, we’ve been deaf.”
The observation of gravitational waves is a monumental step forward. It’s the first direct detection of black holes. It confirms Einstein’s theory of general relativity, which predicts that space-time, the very fabric of existence, can ripple due to the effect of gravity. And it means that we can now probe space in an new away, giving us new potential to make even more discoveries. It’s a cause for great celebration for all humanity.
I see this discovery as not simply monumental for us humans, but as a possible milestone in the history of the Universe itself. Although black holes have been colliding and causing gravitational waves over billions of years, this may be the first time ever that any sentient being has observed it. To borrow the analogy from philosopher George Berkeley’s famous thought experiment, the collision of the black holes was like an enormous tree falling, the crashing sound of which reverberated throughout the immense forest surrounding it. Countless “trees” must have fallen in this “forest” throughout history, but was there anyone around to hear it before?
Well, there definitely is now. Humans have heard the tree fall. If we are the first entities to have detected it and understood its significance, this gives new meaning to the event that it never had before. As intelligent, conscious creatures, and as part of the Universe, we are the way in which the Universe observes itself. And because of our scientists who have made this discovery, you can say that the Universe is more self-aware than it was before. The bonds between ourselves and the Universe, and therefore our deities, are now a little stronger than they were a week ago.
Image: Artist’s impression of two black holes merging. Public domain.