Ask Ethan: Could Matter Escape The Event Horizon During A Black…

Ask Ethan: Could Matter Escape The Event Horizon During A Black Hole Merger?

If two black holes merge, is it possible for matter that was within the event horizon of one black hole to escape? Could it escape and migrate to the other (more massive black hole)? What about escape to outside of both horizons?

Imagine that you’ve got two black holes about to merge in space. They’re radiating energy away, spacetime itself is at its most distorted, and perhaps you have particles just crossing over the event horizon for the first time. Is there any way you could configure it to have them escape, or to have a particle jump from one event horizon to another? The situation is incredible, and involves some of the strongest gravitational fields ever considered in the Universe. But numerical relativists are up to the challenge of simulating these spacetimes, and we can see what happens! Believe it or not, even as energy is radiated away and the total mass drops, the event horizons themselves never decrease in size, and the total volume encapsulating the “no-escape zone” only increases as time goes on!

Come learn the reason why matter can’t escape the event horizon, even during a black hole merger, on this week’s Ask Ethan!