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Third Gravitational Wave Detected From Black-Hole Merger 3 Billion Light Years Away (bbc.com)
sycodon quotes a report from The New York Times (Warning: may be paywalled; alternate source): Astronomers said Thursday that they had felt space-time vibrations known as gravitational waves from the merger of a pair of mammoth black holes resulting in a pit of infinitely deep darkness weighing as much as 49 suns, some 3 billion light-years from here. This is the third black-hole smashup that astronomers have detected since they started keeping watch on the cosmos back in September 2015, with LIGO, the Laser Interferometer Gravitational-Wave Observatory. All of them are more massive than the black holes that astronomers had previously identified as the remnants of dead stars. The latest detection was made at 10:11 GMT on January 4, and is described in a paper accepted for publication in the journal Physical Review Letters. "The analysis suggests the two black holes that coalesced had starting masses that were just over 31 times and 19 times that of our Sun," reports BBC. "And when they finally came together, they produced a single object of a little under 49 solar masses. It means the unison radiated a simply colossal quantity of pure energy."
A collision briefing putting out more power than the rest of the observable universe, wiping out who knows how many intelligent civilisations in an instant. Kind of puts the Trump thing in perspective, I suppose.
The missing mass was radiated away as waves in the gravitational field of the black holes. Think of it this way: when a black hole is static (relative to the total mean gravitational field of the rest of the observable universe) nothing much happens. If, somehow, a black hole were to start vibrating back and forth, it would be tugging at EVERYTHING, and moving EVERYTHING, back and forth. So the movement of the black hole is radiated out into movement of the universe, through dilations in space-time.
Now, every mass that moves does the same thing, but most masses are small enough that they don't much affect anything beyond a small distance. Black holes are big enough that they do have a measurable effect, even at enormous distances.
Think of the energy that gets released by an earthquake: it gets turned into shaking of big, massive things. That energy eventually turns into heat, but during the release: low-frequency shaking of things with great mass, mostly through semi-rigid coupling (which, ultimately, mostly means through electric fields). The same is happening with two black holes as they merge: they shed energy in the form of shaking everything else as they spiral inward.
At least that's as much as my non-physics-PhD head has been able to understand. I hope that someone who actually knows will be able to correct it.
Put my fist through my alarm clock with its ding-dong death inside my ear. - The Blackjacks.