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LIGO detects most massive black hole merger to date

(www.caltech.edu)
360 points Eduard | 1 comments | 14 Jul 25 20:06 UTC | HN request time: 0.225s | source
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WrongOnInternet ◴[14 Jul 25 21:27 UTC] 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.

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aaronharnly ◴[15 Jul 25 00:27 UTC] No.44566715[source]▶
Let’s see — the Tsar Bomba nuclear weapon released the equivalent of converting about 2.3 kg of matter into energy (1).

One solar mass is about 2 x 10^30 kg, so round numbers this event released the same as 10^31 Tsar Bombas, which is … a lot of energy? That number is too big to be a good intuition pump.

Let’s try again: over the course of its entire lifetime of about 10 billion years, the sun will release about 0.034% of its mass as energy (2). So one solar mass of energy is about 3000 solar-lifetime-outputs.

So this event has released about as much energy as 45,000 suns over their entire lifetime. I’m not sure how much of the energy was released in the final few seconds of merger, but probably most of it? So… that’s a lot of energy.

(1) https://faculty.etsu.edu/gardnerr/einstein/e_mc2.htm

(2) https://solar-center.stanford.edu/FAQ/Qshrink.html

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ChuckMcM ◴[15 Jul 25 03:59 UTC] No.44567702[source]▶
Yeah, it's alot alot :-). Over on Mastodon I asked Phil Plait (@badastro) if the "missing mass" in the universe might be a result of black holes converging[1]. He wrote up this event in his newsletter[2] and points out that when they merge, they emit more energy in that instant than every single start in the universe in the same instant. So kind of like an instant of double energy. Hard to fathom how much energy that is with my meager mammalian brain.

[1] https://mastodon.social/@badastro/114852139083587160

[2] https://badastronomy.beehiiv.com/p/the-biggest-black-hole-me...

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anton-c ◴[15 Jul 25 13:52 UTC] No.44571185[source]▶
I can't even understand how supernovae emit like "more energy than than the sun over it's entire lifetime"

Just... how? I get what happens with fusion but the numbers are so mind boggling. And it makes what seems like a terrifying ball of fire appear as a space heater in comparison. It's nuts. The GW thing you mention is near incomprehensible to me.

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1. jerf ◴[15 Jul 25 16:53 UTC] No.44573242[source]▶
At this scale it can help to think in terms of mass rather than energy. The most energy the sun could ever emit over its lifetime is if it was completely converted into energy. However, this merger emitted 15 times the mass of the sun as energy. I don't have all the numbers on tap for supernovas but given that the sun won't convert all its mass to energy, it's not hard for a supernova to convert more mass in its explosion into energy than the sun ever will.