Jump to content

Between two overlapping event horizons....

Featured Replies

....a particle's caught.

 

The situation: two black holes passed near each other, like so...

 

 

fy251c.jpg

 

 

Their event horizons slightly overlap, with a particle caught exactly in the middle of this overlap. Now the black holes continue on their merry way. The particle must leave with one black hole, yet at the same time it must leave the other black hole. Thus does it violate a scientific principle? For now there would be something able to escape an event horizon.

 

A side question...if a photon were caught instead of a particle, does anything interesting/unusual happen to its movement?

the event horizons would not be circular, they would have deformed considerably in such close proximity.

  • Author

Or it could've just entered one first, moments before the second overtook it.

How do two black holes have their event horizons overlap, then "continue on their merry way"?

  • Author
How do two black holes have their event horizons overlap, then "continue on their merry way"?

Hurtling fast enough through space?

 

But remember, an event horizon isn't a real physical object and so can't be trapped by gravity anyway...I presume.

the event horizons would not be circular, they would have deformed considerably in such close proximity.

As an even stronger statement: I strongly expect they'd merge into a single shell as soon as they touch. Reason: Consider the classical gravitational field and two equi-potential spheres around the centers of two circular masses. When the masses approach, the two spheres deform and at a closer distance merge into one.

Since the event horizon is somwhat similar to an equi-potential area in concept and relativistic gravity is similar to classical gravity (admittedly: the similarity is not a quantitative one close to an event horizon) I'd expect the event horizons to behave similarly.

Edited by timo

How do two black holes have their event horizons overlap, then "continue on their merry way"?

Hurtling fast enough through space?

Well, in my layman's view of General Relativity and Gravitational Potential, it seems that for the Event Horizons of two Black Holes to barely thouch each other during a close approatch and still be able to separate, they would need to have a relative speed equal that of light, if the Event Horizons where to overlap their relative speed would have to be greater than the speed of light.

  • Author
As an even stronger statement: I strongly expect they'd merge into a single shell as soon as they touch. Reason: Consider the classical gravitational field and two equi-potential spheres around the centers of two circular masses. When the masses approach, the two spheres deform and at a closer distance merge into one.

If so, then each black hole would suddenly be inside a larger event horizon and neither one could escape. Therefore the particle's never going to leave anyway in your scenario, as the black holes each would be stuck in the newly formed/merged event horizon.

 

But do we know for sure the event horizons would instantly become one? Now that I'm visualizing it, you deduction seems highly possible, but I'd like confirmation.

Archived

This topic is now archived and is closed to further replies.

Important Information

We have placed cookies on your device to help make this website better. You can adjust your cookie settings, otherwise we'll assume you're okay to continue.

Configure browser push notifications

Chrome (Android)
  1. Tap the lock icon next to the address bar.
  2. Tap Permissions → Notifications.
  3. Adjust your preference.
Chrome (Desktop)
  1. Click the padlock icon in the address bar.
  2. Select Site settings.
  3. Find Notifications and adjust your preference.