The Bridge: Discuss an Astronomy Picture of the Day • APOD: Simulation: Two Black Holes Merge (2024 May 10)

Neither black hole lost mass. The individual precursor black holes merged to form a new black hole, and it has a higher mass than either of the precursors. The total mass difference reflects the conversion of gravitational potential energy (as the two precursors got closer) into kinetic energy, and that into gravitational waves.

Kinetic energy can get converted into gravitational energy? In the mundane world, kinetic energy clearly can get converted into heat (a bullet hitting
a steel plate for example), but does it also get converted to GWs (however miniscule an amount that might result in)?

In the mundane world, gravitational potential energy gets converted to kinetic energy, gets converted to gravitational waves all the time. Like when you drop a rock. But it takes something as massive as merging black holes or neutron stars to produce strong enough gravitational waves for our existing technology to detect them.

(Perhaps we should read this as an indicator that the "mundane world" is much less mundane than it superficially appears!)

Statistics: Posted by johnnydeep — Fri May 10, 2024 6:12 pm — Replies 11 — Views 240