This is an amazing day for humanity! Notice I said humanity, not science, not physics – humanity. The LIGO experiment has announced the discovery of a direct detection of gravitational waves (actual ripples in spacetime itself!!), opening a whole new window with which to see and understand the universe. This is equivalent to Galileo first pointing a telescope at the sky and beginning to see things like the moons of Jupiter and the phases of venus for the first time. Look how much we learned following from that… so we’ve a lot to look forward to. It is 100 years ago since gravitational waves were predicted, and we’ve now seen them directly for the first time!
Actually, more has been discovered in this announcement:- The signal came from the merger of two large (stellar) black holes, and so this is also the first direct confirmation of such black holes’ existence! (We’ve known about them indirectly and also about supermassive black holes in the cores of galaxies, but this is a real direct detection of stellar black holes – black holes that probably resulted from the collapse of stars…)
The other great thing is that there are several new wave detection experiments about to come on line around the world over the next few years, and the resulting network of detectors should allow us to begin to map out the events/objects in the sky as we detect the ripples from them. The prospects are fascinating.
There’s all sort of press coverage and writings about this, if you want to read more. I’ll point you to one of many good ones, Matthew Francis’ piece “A Dawn of a New Era in Science” in the Atlantic, from which I cheekily snapped the graphic at the top.
Enjoy! – and Celebrate!