# White Hole and Black Hole

1. Jul 9, 2004

### Tim

This probably could never happen but hypathetically speaking what would happen if a White Hole Collided with a Black Hole?

Sincerely
Tim

2. Jul 9, 2004

### mathman

It is hard to say, particularly since the concept of white hole is very hypothetical. For ordinary stuff, black holes would simply swallow it.

3. Jul 11, 2004

### Mistic

Stricktly speaking.....

Its not likely to happen. A present a white hole is only hypothetical, but since a white hole is the exact opposite of a black hole, then if they collided it is likely they would nutralize each other. Kinda like when matter and anti-matter come togather.

4. Jul 11, 2004

### Tom McCurdy

can someone tell me what white hole is?

5. Jul 11, 2004

### Entropy

Right now white holes are practically make believe so it can do whatever you want.

6. Jul 12, 2004

### idontthinkright

i know~! When a white hole and a black hole collides it will form a grey hole! lolz just kidding.Black holes would be too vast for the white hole, in hypothesis, the white hole would be sucked up.

7. Jul 12, 2004

### europium

Tom, in theory, a white hole is the exact opposite of a black hole. Therefore, whereas black holes 'suck things in', a white hole will 'spit things out' that had originally entered the black hole. However, white holes are almost definately hypothetical only.

Kyle

8. Jul 12, 2004

### Tom McCurdy

are you saying they are the place that the things crushed into a singulatiry would emit from... which would require wormhole or alt univerese?

9. Jul 13, 2004

### balkan

yes... welcome to star trek...

10. Jul 14, 2004

### Orion1

Schwarzschild Scheme...

The hypothetical antithesis of a black hole, a white hole spews matter out. No antigravitational field has been discovered that actually produces this effect, however, so white holes remain purely speculative. One way wormholes could feasibly be generated is as a black hole that is attached to a white hole if they are found to exist.

Some speculation exists that quasars are actually white holes instead of supermassive black holes, but this is not widely accepted within the astronomical community.

Another strange solution is the "white hole," which in many respects is the mirror image of the black hole; rather than matter disappearing into the hole, matter appears at a white hole, and nothing can remain in the white hole. However, there is no evidence that white holes could form in the physical universe. Black holes are created when massive stars collapse, or perhaps by the collapse of extremely dense star clusters at the center of galaxies, but white holes would have to be placed ab initio into the universe.

The Schwarzschild metric admits negative square root as well as positive square root solutions for the geometry.

The complete Schwarzschild geometry consists of a black hole, a white hole, and two Universes connected at their horizons by a wormhole.

White holes cannot exist, since they violate the second law of thermodynamics.
what would happen if a White Hole Collided with a Black Hole?

Given that their masses are equivalent $$dm_b = dm_w$$ and their Schwarzschild metrics and Schwarzschild geometries are mirror images, $$ds_b^2 = -ds_w^2$$, they would annihilate each other similarly to a matter-antimatter reaction. However, there would still be a remnant energy product, because energy is always conserved.

Reference:
http://www.astro.virginia.edu/~jh8h/Foundations/chapter9.html
http://www.wordiq.com/definition/White_hole

11. Jul 14, 2004

### techwonder

Orion1,

If nothing can remain inside a white hole, then it cannot have mass. I'd say that the white hole bounces of the black hole. They could never merge.

12. Jul 14, 2004

### balkan

hmm... matter and antimatter is being generated all the time in this universe... perhaps this originates from white holes, on the other end of black holes? ... it's worth considering anyway ... :D

13. Jul 18, 2004

### Tim

Dose this mean that if they collided that perhaps the energy remmant would be a star.

14. Jul 19, 2004

### urtalkinstupid

white holes

Where has it been said that matter and anti-matter neutralize each other? When matter and anti-matter collide they do not neutralize, rather they annhilate each other.

Yes, not only are white holes hypothetical, but black holes are hypothetical also. Even Einstein had disbelief in his mathematical equations proving a black hole much less a white hole.

Oh, is it even hypothesized that black holes and white holes are even in the same universe?

Last edited: Jul 19, 2004
15. Jul 19, 2004

### Chronos

I will ponder the existence of 'white holes' right after the anti-graviton is detected.

16. Jul 19, 2004

### CJames

Aren't there some theories out there that say a white hole is simply a black hole? A white hole does everything exactly the opposite of a black hole. Therefore, a white hole would run backward in time. Now what is something that is constantly spitting out matter in reverse time? A black hole in forward time. Kinda like how an anti-photon is a photon.

17. Jul 20, 2004

### Lama

Maybe the big-bang is a white hole.

18. Jul 20, 2004

### Orion1

If nothing can remain inside a white hole, then it cannot have mass. I'd say that the white hole bounces of the black hole. They could never merge.

I have not found anything in the metrics which states that white holes cannot contain mass or cannot merge. It is certainly possible for the metrics to annihilate each other through simple addition. White holes can only exist by being fed matter and energy from a black hole through a wormhole, however note that the white hole metric geometry for this type of mathematical object is still purely hypothetical. According the the negative Schwarzschild metric solution in general relativity, white holes are based upon mass, however such a mass is probably reflected as hypothetical 'negative mass'.

Dose this mean that if they collided that perhaps the energy remmant would be a star.

Negative, an explosion this energic and powerful would not produce any known cohesive structure, such an explosion is probably similar to, or more energtic than, a hypernova.

The following reference is an excellent source for examining the metrics for black hole, white holes and wormholes geometries.

Reference:
http://www.geocities.com/zcphysicsms/chap12.htm