# White Holes **URL:** \ **Category:** Factual Questions\ **Created:** [August 3, 2017, 12:47pm UTC](https://boards.straightdope.com/t/white-holes/792689 "2017-08-03T12:47:59Z")\ **Posts on this page:** 8\ **Page:** 3
**Author:** ![DSeid](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/dseid/32/20194_2.png) [@DSeid](https://boards.straightdope.com/u/DSeid)\ **Post date:** [August 5, 2017, 11:14pm UTC](https://boards.straightdope.com/t/white-holes/792689/41 "2017-08-05T23:14:00Z")
**Chronos** , The point of that sun comment, as I read it, was that our op refused to define the term, or to link to a page giving one, copping out that anyone who could answer would know what it was, leading many readers to reasonably conclude that the op had no freakin’ idea what they were even asking about. Having had the term defined, the op is answered: no white holes have been definitively observed because there likely are none as there are no mechanisms consistent with an inflationary universe running time as it does that would produce them. (Which of course anyone who knew what a white hole was would know.) What would a definite observation of a “white hole”, as now defined, observable to us traveling through time in the direction we do, imply “we” have wrong in our current models? Or alternatively which highly speculative models not inconsistent with what has otherwise been observed would the observation support? ---
**Author:** ![DPRK](https://avatars.discourse-cdn.com/v4/letter/d/4491bb/32.png) [@DPRK](https://boards.straightdope.com/u/DPRK)\ **Post date:** [August 5, 2017, 11:42pm UTC](https://boards.straightdope.com/t/white-holes/792689/42 "2017-08-05T23:42:08Z")
> [@Chronos](#): > > When physicists use the word “classical”, they mean “non-quantum”, and white holes don’t emerge from quantum mechanics, so in that sense, they’re classical. What you might have meant was that they’re not Newtonian, being purely objects of general relativity. By “classical” I meant what you meant, which is “non-quantum”, or more precisely, gravitation as in Einstein’s field equations. I know how to create a black hole, by creating a massive star and waiting for it to collapse. I don’t know how to create a white hole, so I was wondering whether some weird, possibly quantum, mechanism I never heard of has been proposed that would generate one, at least a small one. Both you and **DSeid** said no, and I assume someone on this board would have heard something about it, so I’m satisfied. (Eta **Asymptotically Fat** mentioned “speculative” methods, which I assume are to be relegated along with time travel and such non-physical reverses.) ---
**Author:** ![Dr.Strangelove](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/dr.strangelove/32/6613_2.png) [@Dr.Strangelove](https://boards.straightdope.com/u/Dr.Strangelove)\ **Post date:** [August 5, 2017, 11:45pm UTC](https://boards.straightdope.com/t/white-holes/792689/43 "2017-08-05T23:45:19Z")
> [@DSeid](#): > > (Which of course anyone who knew what a white hole was would know.) That’s not true. One of my favorite books as a kid was one on black holes. It talked about many speculative objects, such as naked singularities and white holes (black holes themselves were somewhat speculative then). I understood it well enough to know that white holes were a kind of reverse black hole, but did not at the time understand the relationship between entropy and time and why a white hole can’t form despite being consistent with the laws of physics. ---
**Author:** ![DSeid](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/dseid/32/20194_2.png) [@DSeid](https://boards.straightdope.com/u/DSeid)\ **Post date:** [August 6, 2017, 12:08am UTC](https://boards.straightdope.com/t/white-holes/792689/44 "2017-08-06T00:08:05Z")
> [@DPRK](#): > > … and **DSeid** said no, and … Let me be very clear that my expertise is limited to having read several posts by those who know the subject well here! Even that wiki article link gets over my head. **Dr. Strangelove** … okay. ---
**Author:** ![eschereal](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/eschereal/32/18939_2.png) [@eschereal](https://boards.straightdope.com/u/eschereal)\ **Post date:** [August 6, 2017, 12:29am UTC](https://boards.straightdope.com/t/white-holes/792689/45 "2017-08-06T00:29:38Z")
> [@Weisshund](#): > > [In general relativity, a white hole is a hypothetical region of spacetime which cannot be entered from the outside, although matter and light can escape from it. In this sense, it is the reverse of a black hole, which can only be entered from the outside and from which matter and light cannot escape.](https://en.wikipedia.org/wiki/White_hole) from the link, > [@](#): > > For an observer outside using Schwarzschild coordinates, infalling particles take an infinite time to reach the black hole horizon infinitely far in the future, while outgoing particles which pass the observer have been traveling outward for an infinite time since crossing the white hole horizon infinitely far in the past (however, the particles or other objects experience only a finite proper time between crossing the horizon and passing the outside observer). This is kind of problematic, given that spacetime AWKI is less that 14Gy/o. That is slightly less than an infinite past – unless time itself bends drastically near the large explosion that created everything. > [@John\_Mace](#): > > There is only one white hole. It exists everywhere that a black hole doesn’t. 😉 No, no, there are a lot of white holes. They just each exist everywhere. Surely we can have distinct omnipresent entities that share the same spacetime, as long as they exist within the paradoxical crease in reality. ---
**Author:** ![Asympotically\_fat](https://avatars.discourse-cdn.com/v4/letter/a/e47c2d/32.png) [@Asympotically\_fat](https://boards.straightdope.com/u/Asympotically_fat)\ **Post date:** [August 6, 2017, 1:00pm UTC](https://boards.straightdope.com/t/white-holes/792689/46 "2017-08-06T13:00:10Z")
> [@DPRK](#): > > What theoretical mechanism could create such a white hole? I suppose this goes beyond classical gravitation? It’s difficult to imagine a physical mechanism of white hole formation. In the extended Schwarzschild solution, whereas the black hole singularity is in the causal future of all events, the white hole singularity is in the causal past of all events. If a white hole formed it is easy to imagine it would not be in the causal past of\* all \*events, but very difficult to see how it could be in the causal future of any events, meaning what and where are the events that cause it to form? That said there are several speculative models invoking quantum physics for white hole formation, I can’t say I have really read much about them though. ---
**Author:** ![Asympotically\_fat](https://avatars.discourse-cdn.com/v4/letter/a/e47c2d/32.png) [@Asympotically\_fat](https://boards.straightdope.com/u/Asympotically_fat)\ **Post date:** [August 6, 2017, 1:04pm UTC](https://boards.straightdope.com/t/white-holes/792689/47 "2017-08-06T13:04:26Z")
> [@eschereal](#): > > from the link, > This is kind of problematic, given that spacetime AWKI is less that 14Gy/o. That is slightly less than an infinite past – unless time itself bends drastically near the large explosion that created everything. I wouldn’t say it’s paradoxical from there being enough time, because the WH event horizon is only in the infinite coordinate past from the pov of some coordinates. The problem is what could happen now at this location to cause it to form if it cannot be in the future this event? ---
**Author:** ![Mangetout](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/mangetout/32/19_2.png) [@Mangetout](https://boards.straightdope.com/u/Mangetout)\ **Post date:** [August 7, 2017, 8:08am UTC](https://boards.straightdope.com/t/white-holes/792689/48 "2017-08-07T08:08:42Z")
> [@abashed](#): > > Okay, so white holes are theoretically possible according to Einstein’s equations but could only exist if we ran back time. > > Thank you people. 🙂 Paging Cher. [Previous page](https://boards.straightdope.com/t/white-holes/792689.md?page=2)