←back to thread

360 points Eduard | 8 comments | | HN request time: 1.112s | source | bottom
Show context
WrongOnInternet ◴[] No.44565549[source]
> the 225-solar-mass black hole was created by the coalescence of black holes each approximately 100 and 140 times the mass of the Sun.

Does this mean that 15 solar masses were converted into energy? Because that's a LOT of energy.

replies(8): >>44565596 #>>44566469 #>>44566715 #>>44566963 #>>44567727 #>>44568821 #>>44569179 #>>44569506 #
1. andrepd ◴[] No.44565596[source]
Yes! And still, gravity is so weak that that immense amount of energy translates to just a relative contraction of less than 10^-20, or about a hair's width in the distance from the Earth to the Moon.
replies(4): >>44565649 #>>44566504 #>>44568702 #>>44571435 #
2. cgdl ◴[] No.44565649[source]
Do we know how far this event was from earth? Wouldn't that distance be the determiner of what the relative contraction observed on earth would be?
replies(1): >>44565766 #
3. sgustard ◴[] No.44565766[source]
estimated distance of 2.2 Gpc per https://en.wikipedia.org/wiki/GW231123
replies(2): >>44567016 #>>44568282 #
4. UltraSane ◴[] No.44566504[source]
At 10 times the Schwarzschild radius Space literally stretches and contracts by 10-100%
5. irjustin ◴[] No.44567016{3}[source]
That's how fast the millennium falcon goes
6. BurningFrog ◴[] No.44568282{3}[source]
That's 7.2 billion light years. More than halfway to the most distant galaxy the Webb telescope has found.

So this event happened 7.2 billion years ago.

There is no mention of in which direction. Maybe the triangulation wasn't working at the time. You need three LIGOs for that.

7. ssl232 ◴[] No.44568702[source]
This is because space is _stiff_. Recall Hooke’s law from high school physics. The k constant represents the stiffness of the object. A rubber band is about 50. A sky scraper, about a million. Space? About 10^46 if I recall correctly. So it takes a truly enormous amount of energy in the form of gravitational waves to be able to move space enough for it to be detectable on Earth. And the only objects that can do that are the most massive ones moving at close to the speed of light: black holes, neutron stars, supernovae (the latter would have to be very close for us to see gravitational waves from - close enough that we’d likely see it with the naked eye as well).
8. misja111 ◴[] No.44571435[source]
Sure but we are 7 billion lightyears away from the source of the waves. Imagine if we'd be a bit closer ..