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Honorable_Death
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If a black hole creates a dent in spactime, would a white hole creat a lump, and if it did would it be in the future?
The "black holes create baby universes" is a hypothesis favored by Lee Smolin, but can it be shown to be a consequence of loop quantum gravity?ohwilleke said:PeteSF. You're not far off. Loop Quantum Gravity people like Smolin would argue that the Big Bang is THE white hole in our universe and that every black hole creates a new "baby universe" with its own white hole/big bang which is the interior of the black hole.
when i used the hole dent and lump analogy i wasnt literally talking bout a dent and lump in our universe, I am talking about how a black hole is going "back in time" because its so massice, or the dent, well what I am really asking is would a white hole go froward in timeJesseM said:You're taking the "rubber sheet" analogy too literally. You shouldn't imagine things being pulled "down" on the rubber sheet, all that matters is that they take the shortest path between two points, known as a geodesic. For example, the shortest path between two points on the curved 2D surface of a sphere would be the section of the great circle that passed through those points. In general relativity geodesics are not actually the shortest paths through curved 3D space, they are the paths through curved 4D spacetime with the largest proper time (proper time is the amount of time registered on a clock that that follows a given path through spacetime). So the rubber sheet analogy only gives a vague idea of how general relativity explains things, you shouldn't take it too seriously.
What do you mean when you say a black hole is going "back in time"? Time slows down close to a black hole (or any other object), meaning that if you spend some time near a black hole and then return to Earth you'll have aged less than everyone else, but you can't go backwards in time by hanging out near a black hole. Time wouldn't speed up near a white hole, if that's what you're asking.Honorable_Death said:when i used the hole dent and lump analogy i wasnt literally talking bout a dent and lump in our universe, I am talking about how a black hole is going "back in time" because its so massice, or the dent, well what I am really asking is would a white hole go froward in time
JesseM said:What do you mean when you say a black hole is going "back in time"? Time slows down close to a black hole (or any other object), meaning that if you spend some time near a black hole and then return to Earth you'll have aged less than everyone else, but you can't go backwards in time by hanging out near a black hole. Time wouldn't speed up near a white hole, if that's what you're asking.
A white hole is just a time-reversed version of a black hole--if you filmed a black hole and played the film backwards, that's pretty much what a white hole should look like. If you see a clock ticking slower near a black hole in your movie, then playing it backwards, the clock will still be ticking slower.Honorable_Death said:y wouldn't time speed up next to a white hole?
JesseM said:A white hole is just a time-reversed version of a black hole--if you filmed a black hole and played the film backwards, that's pretty much what a white hole should look like. If you see a clock ticking slower near a black hole in your movie, then playing it backwards, the clock will still be ticking slower.
Good question, but I don't know, maybe one of the GR experts here could answer that question. I suppose this must be analogous to the question, "if you see an object near the event horizon of a black hole but flying away from it, what would you 'retrodict' for that object's past history?" Maybe the only way to explain it would be to suppose that it interacted with another object in such a way that its trajectory was altered, like if it was originally riding along with a rocket falling into the black hole but the people on board shot it away before they crossed the horizon. If that's correct, then it seems the answer to the question of what would happen to an object falling into a white hole would be that some object coming out of the white hole will always interact with it in such a way that it is deflected away from the horizon. This seems pretty strange, but then if a white hole is exactly like a time-reversed black hole we should expect the thermodynamic arrow of time to go in reverse in its vicinity, leading to all sorts of strange events. So maybe that means that white holes fall into the same category as phenomena like pieces of broken eggshell spontaneously jumping together and forming an intact egg--allowed by the fundamental laws of physics, but terrifically unlikely due to the second law of thermodynamics.PeteSF said:That's interesting... so a white hole is still a deep gravity well?
Thinking...
What would happen to an object that fell toward a white hole from some distance?
No, a star collapsing would not look like the time-reverse of a black hole forming, a star collapsing is a black hole forming if the mass is large enough. A reversed collapse would look like a black hole spewing out matter until it becomes a star (or some other dense collection of matter/energy).Spin_Network said:So..a Star collapse that create's a Blackhole, is the Time-reversed of a White hole?..thus Stars 'ARE' white holes?..so I look out into the night sky I am seeing White Holes embedded in universal a Dark Hole?..are you sure about those time-reversed implications?
Yes, as I said in my post to PeteSF, I think a white hole would involve a huge violation of the second law of thermodynamics, which is probably why physicists don't think they're likely to exist in spite of being a perfectly valid solution to the time-symmetric equations of GR (http://casa.colorado.edu/~ajsh/schww.html mentions that "White holes cannot exist, since they violate the second law of thermodynamics.") Similarly, the time-symmetric laws of quantum mechanics do allow for things like pieces of eggshell jumping together and forming an intact egg, but this is also extremely unlikely statistically.Spin_Network said:If I film a Star collapsing in a 'forward' time, and a Blackhole appears..the event-horizon is external to the Blackhole singularity..it is the last remaining remnant signiture, but then if I Rewind 'backwards' in time, "from the event-horizon" to the 'COMPLETE', uncollapsed star which is the time-reversed scenario that you imply, then the 'locked-up' information that was lost to the Blackhole would have to be EXTRACTED in order to complete the construction of the physical Star!
JesseM said:No, a star collapsing would not look like the time-reverse of a black hole forming, a star collapsing is a black hole forming if the mass is large enough. A reversed collapse would look like a black hole spewing out matter until it becomes a star (or some other dense collection of matter/energy). Yes, as I said in my post to PeteSF, I think a white hole would involve a huge violation of the second law of thermodynamics, which is probably why physicists don't think they're likely to exist in spite of being a perfectly valid solution to the time-symmetric equations of GR (http://casa.colorado.edu/~ajsh/schww.html mentions that "White holes cannot exist, since they violate the second law of thermodynamics.") Similarly, the time-symmetric laws of quantum mechanics do allow for things like pieces of eggshell jumping together and forming an intact egg, but this is also extremely unlikely statistically.
JesseM said:A white hole is just a time-reversed version of a black hole--if you filmed a black hole and played the film backwards, that's pretty much what a white hole should look like. If you see a clock ticking slower near a black hole in your movie, then playing it backwards, the clock will still be ticking slower.
A white hole is a hypothetical object that is the opposite of a black hole. While a black hole has such strong gravitational pull that nothing, including light, can escape from it, a white hole has an outward flow of matter and energy, making it impossible for anything to enter it.
White holes are theorized to have a repulsive gravitational force, causing spacetime to expand rather than contract like it does around a black hole. This could potentially lead to the creation of new universes or the destruction of existing ones.
At this time, there is no evidence to suggest that white holes actually exist. They are purely theoretical and have not been observed or detected by any scientific instruments.
Since white holes are considered to have an outward flow of matter and energy, it is believed that any object that enters a white hole would be pushed away and ejected back into the universe.
Some theories suggest that white holes could potentially be used as a means of time travel, as they may have the ability to transport matter and energy to different points in spacetime. However, this is currently only speculation and has not been proven.