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White hole 
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#1
May405, 09:16 PM

P: 38

If a black hole creates a dent in spactime, would a whitehole creat a lump, and if it did would it be in the future?



#2
May405, 09:27 PM

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P: 8,470

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.



#3
May405, 09:31 PM

P: 90

I think that a whitehole is a solution to the GRT field equations that is the same as a blackhole solution but with the time reversed.
Both have a singularity in the middle, cloaked by an Event Horizon. Anything can enter a black hole, but nothing can escape. Anything could escape a white hole, but nothing could enter. A black hole is formed when enough massenergy is concentrated in a small enough space. A white hole might "die" if enough massenergy escaped at once? (I'm speculating on this  I wouldn't have a clue how to begin to approach the maths) A black hole "dies" when the event horizon evaporates with a huge burst of radiation. I don't know if there is any mechanism postulated for the formation of a whitehole eventhorizon. One kooky idea that I came up with (then promptly found that it wasn't original after all) is that the view from inside a large enough white hole could conceivably look much like our Universe... 


#4
May405, 10:51 PM

PF Gold
P: 643

White hole
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.



#5
May405, 11:06 PM

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#6
May605, 11:45 AM

P: 38




#7
May605, 12:29 PM

P: 1,373

if i remmeber correctly A white hole isn't stable...people coming outta the singular are trapped.



#8
May605, 12:36 PM

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#9
May905, 11:33 AM

P: 38




#10
May905, 12:56 PM

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#11
May905, 06:13 PM

P: 90

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? 


#12
May905, 11:51 PM

P: 408

If I film a Star collapsing in a 'forward' time, and a Blackhole appears..the eventhorizon is external to the Blackhole singularity..it is the last remaining remnant signiture, but then if I Rewind 'backwards' in time, "from the eventhorizon" to the 'COMPLETE', uncollapsed star which is the timereversed scenario that you imply, then the 'lockedup' information that was lost to the Blackhole would have to be EXTRACTED in order to complete the construction of the physical Star! I think you should try to understand the dynamical implications of what your stating?..the time ordering of Whitehole<>Blackhole and Blackhole><Whitehole is where the problems lay, the TIME horizon is not connected to the Singularity Horizon, events of Time in one collapse (Stellar collapse) for instance, do not allow EVENTS to be frozen, the ticks you are talking about "follow=through" and cannot be observed from an external observation reference frame, thus from an observational point of view the Star dissapears and a Blackhole appears, they cannot..I repeat..cannot be reconstructed without ALL the paramiters one started from, thus the TIMEPARAMITER cannot be reconstituted from "Stellar" created Blackholes, its a oneway dynamical operation. Trying to create 'events' at the limit of collapse is trying to stabilize the collapse into time orderings where pastpresentfuture are overlapping and do not really 'exist', to do this one has to find the Universal Singularity Event. There are recent implications for "timereversed" equations that are being reformulated by some of the worlds topheads, the 'information_paradox' that leads to whitehole, blackhole paradoxes, are being bent..strightened..and unwarped by leading theorists today, there is a growing consensus that Science had taken the wrong road (would not be the first time!)..in not the overall theory, but just the understanding Einsteins Generalized Field Equations. 


#13
May1005, 01:22 AM

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#14
May1005, 01:33 AM

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#15
May1005, 02:14 AM

P: 408

of course things have been moving quite further from that, the Universe is thought NOT to be a pressureless fluid, its dynamical and this recent paper goea a long way into details:http://arxiv.org/abs/grqc/0505032 actually gives a good example of the Hydrogen Atom in a New light? I may state that the Pressureless fluid is thought to be the 'Negative Space' in some models between Galaxies..far from positive matter. The recent paper I linked to goes a good way to stating that the Blackhole Singularities created by Stars, is discrete from the Universal Singularities that create Galaxies..and thus Hydrogen?..they take the limit of LQG(loop quantum Gravity), and using LQC,(Loop Quantum Cosmology) find that 'seperation' is th key to understanding. A uniform Phase Space (pressureless Sphere) has within its substance, an ununformed Geometry, now this is to say that if one was to be contained within a present GR frame of reference, lets say from within our Galaxies, and one was to Quantizise the Geometry of Space you are contained with, then the solution to Einsteins Field Equations leads down to a LQG structure, generalised to the Hydrogen Atom. Now the same paper is more or less stating, if one starts from the same Ref frame, and extrapolates outwards into the LQC domain,,then there are different solutions..LQG is NOT found in the LQC...open Universe! P.S there are recent posters who have been advocating this scenario, and at a price of being banned:http://www.physicsforums.com/showthread.php?t=41455 yet if one looks closely..page ten of this:http://arxiv.org/PS_cache/hepth/pdf/0408/0408220.pdf then one can clearly see that there is a major shift occurring in some Cosmological theoricians thinking. As far as I understand that is? 


#16
May1005, 11:44 AM

P: 38




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