# So...black holes don't exist now? **URL:** \ **Category:** Factual Questions\ **Created:** [September 24, 2014, 10:20pm UTC](https://boards.straightdope.com/t/so-black-holes-dont-exist-now/699470 "2014-09-24T22:20:15Z")\ **Posts on this page:** 20\ **Page:** 1
**Author:** ![njtt](https://avatars.discourse-cdn.com/v4/letter/n/ecd19e/32.png) [@njtt](https://boards.straightdope.com/u/njtt)\ **Post date:** [September 24, 2014, 10:20pm UTC](https://boards.straightdope.com/t/so-black-holes-dont-exist-now/699470/1 "2014-09-24T22:20:15Z")
> **[Researcher shows that black holes do not exist](https://phys.org/news/2014-09-black-holes.html)** > > Black holes have long captured the public imagination and been the subject of popular culture, from Star Trek to Hollywood. They are the ultimate unknown – the blackest and most dense objects in the universe that do not even let light escape. And as... Physics/astronomy dopers, is this bad reporting, plausible, BS, or have we all been fooled, for years, into believing in phlogiston again? > [@](#): > > The take home message of her work is clear: there is no such thing as a black hole. > > … > > Experimental evidence may one day provide physical proof as to whether or not black holes exist in the universe. But for now, Mersini-Houghton says the mathematics are conclusive. That paragraph does rather seem to contradict itself. ---
**Author:** ![Habeed](https://avatars.discourse-cdn.com/v4/letter/h/a587f6/32.png) [@Habeed](https://boards.straightdope.com/u/Habeed)\ **Post date:** [September 24, 2014, 10:28pm UTC](https://boards.straightdope.com/t/so-black-holes-dont-exist-now/699470/2 "2014-09-24T22:28:09Z")
The paper never says anything about a black hole being impossible. Just that the current stellar collapse model doesn’t pass the pencil test to form a black hole. I read [a paper](http://arxiv.org/pdf/0908.1803.pdf) on hypothetically forming an artificial black hole. The problem is that you must cram an incredible amount of mass-energy into the black hole before it is even stable enough that it won’t evaporate instantly. This makes creating an artificial one incredibly difficult. Were you to simply try to squeeze mass together, the moment it passes the threshold to become a black hole, hawking radiation is so intense that the black hole instantly evaporates. The proposed method that has a chance of working is to fire relativistic rods that have to total about 1 million tons of mass-energy. The rods slam into each other and create a compressed point of matter so dense that it won’t evaporate from hawking radiation. The problem is that there might not be enough mass in our solar system to build the apparatus needed to do this. (even if you had the self replicating robotics, etc, you would need in order to even consider a project like this) ---
**Author:** ![Exapno\_Mapcase](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/exapno_mapcase/32/1051_2.png) [@Exapno\_Mapcase](https://boards.straightdope.com/u/Exapno_Mapcase)\ **Post date:** [September 24, 2014, 10:35pm UTC](https://boards.straightdope.com/t/so-black-holes-dont-exist-now/699470/3 "2014-09-24T22:35:39Z")
The article is explicit: > [@](#): > > The take home message of her work is clear: there is no such thing as a black hole. It doesn’t even begin to answer the question of what it is that is seen at the centers of galaxies if that is true. I suspect a huge gap between the paper and the report, which is merely a reprint of the [UNC press release](http://unc.edu/spotlight/rethinking-the-origins-of-the-universe/). ---
**Author:** ![halfreal](https://avatars.discourse-cdn.com/v4/letter/h/ccd318/32.png) [@halfreal](https://boards.straightdope.com/u/halfreal)\ **Post date:** [September 24, 2014, 11:15pm UTC](https://boards.straightdope.com/t/so-black-holes-dont-exist-now/699470/4 "2014-09-24T23:15:22Z")
> **[Physicist Claims to Have Proven Mathematically That Black Holes Do Not Exist](https://www.iflscience.com/physicist-claims-have-proven-mathematically-black-holes-do-not-exist-25783)** > > Physicist Claims to Have Proven Mathematically That Black Holes Do Not Exist ---
**Author:** ![Grey](https://avatars.discourse-cdn.com/v4/letter/g/b782af/32.png) [@Grey](https://boards.straightdope.com/u/Grey)\ **Post date:** [September 24, 2014, 11:30pm UTC](https://boards.straightdope.com/t/so-black-holes-dont-exist-now/699470/5 "2014-09-24T23:30:55Z")
Well their numerical simulations suggest that as the star collapses Hawking radiation ramps up effectively reducing the star’s mass and slowing the collapse. Paper is here - [[1409.1837] Back-reaction of the Hawking radiation flux on a gravitationally collapsing star II](http://arxiv.org/abs/1409.1837) The problem, aside from trying to explain existing phenomena we call black holes is that their code fails just at the point where it looks like neat things happen. It’s a numerical simulation so extreme conditions are going to involve extreme reactions. > [@](#): > > The key idea that enables this program is the fact that radiation is produced during the collapse stage of the star, prior to black hole formation. Once the star becomes a black hole nothing can escape it, not even light. Since Hawking radiation is produced prior to black hole formation then its back reaction on the star’s evolution can be included in the set of hydrodynamic equations for the coupled system of the quantum field and the star. Thus we solve numerically the set of hydrodynamics equations describing the evolution of collapse for the inhomogeneous dust star absorbing negative energy Hawking > ux during its collapse. We discover that the stars explode instead of collapsing to a black hole, as they get close to their last stage of collapse, just when Hawking radiation reaches a maximum, but they never cross what would have been the apparent horizon. Just like Hawking radiation which is universal, we discover that this behaviour of the collapsing stars bouncing and exploding before the horizon and singularity would have formed, is universal, i.e independent of their characteristics such as mass and size. Physically the back reaction of ingoing negative energy Hawking radiation reduces the gravitational binding energy in the star with the maximum loss near the last stages of collapse, while taking momentum away from the star. ---
**Author:** ![dracoi](https://avatars.discourse-cdn.com/v4/letter/d/90db22/32.png) [@dracoi](https://boards.straightdope.com/u/dracoi)\ **Post date:** [September 24, 2014, 11:37pm UTC](https://boards.straightdope.com/t/so-black-holes-dont-exist-now/699470/6 "2014-09-24T23:37:25Z")
Wait a minute… both linked articles claim that she’s reconciled relativity and quantum mechanics, and we’re supposed to be excited about whether or not black holes exist? I think I’ll write my own news article. Headline: “Isaac Newton enjoyed a tasty apple” and then, two paragraphs from the end, I’ll comment: “He also came up with the theory of gravity and some fancy math that uses squiggly lines.” ---
**Author:** ![Grey](https://avatars.discourse-cdn.com/v4/letter/g/b782af/32.png) [@Grey](https://boards.straightdope.com/u/Grey)\ **Post date:** [September 24, 2014, 11:40pm UTC](https://boards.straightdope.com/t/so-black-holes-dont-exist-now/699470/7 "2014-09-24T23:40:23Z")
I’d be interested in knowing if they have a specific emission profile that could be reconciled with actual stellar collapses. ---
**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:** [September 25, 2014, 12:16am UTC](https://boards.straightdope.com/t/so-black-holes-dont-exist-now/699470/8 "2014-09-25T00:16:56Z")
> [@dracoi](#): > > I think I’ll write my own news article. Headline: “Isaac Newton enjoyed a tasty apple” and then, two paragraphs from the end, I’ll comment: “He also came up with the theory of gravity and some fancy math that uses squiggly lines.” Gottfried Leibniz invented the (use of) squiggly lines, and was kind of concurrent with Issac Newton as far as the overall methodology. Newton used some sort of “dot notation” that never became popular. ---
**Author:** ![KarlGauss](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/karlgauss/32/3713_2.png) [@KarlGauss](https://boards.straightdope.com/u/KarlGauss)\ **Post date:** [September 25, 2014, 12:28am UTC](https://boards.straightdope.com/t/so-black-holes-dont-exist-now/699470/9 "2014-09-25T00:28:54Z")
Just to be clear, both the paper in question and the comments above (i.e. **Grey** ’s quote), seem to be stating that Hawking Radiation is not emitted by a black hole _per se_ but, rather, arises from the intense gravitational field just outside the event horizon. Have I got that right? If so, does that imply that the detection of Hawking Radiation would not necessarily imply the existence of a black hole (i.e. it could come from any _very_ strong and compact gravitational field, and not just from a BH)? Thanks! ---
**Author:** ![John\_DiFool](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/john_difool/32/19543_2.png) [@John\_DiFool](https://boards.straightdope.com/u/John_DiFool)\ **Post date:** [September 25, 2014, 12:32am UTC](https://boards.straightdope.com/t/so-black-holes-dont-exist-now/699470/10 "2014-09-25T00:32:11Z")
Maybe black holes don’t exist _now_ because it would take an infinite amount of time for them to collapse to become one? ---
**Author:** ![njtt](https://avatars.discourse-cdn.com/v4/letter/n/ecd19e/32.png) [@njtt](https://boards.straightdope.com/u/njtt)\ **Post date:** [September 25, 2014, 12:40am UTC](https://boards.straightdope.com/t/so-black-holes-dont-exist-now/699470/11 "2014-09-25T00:40:11Z")
> [@Exapno\_Mapcase](#): > > The article is explicit: > It doesn’t even begin to answer the question of what it is that is seen at the centers of galaxies if that is true. What do you mean by “seen” in that sentence. I think what you mean is “inferred” from certain measurements (very likely manifest as a numerical printout), via a lot of theory and some quite complex math. ---
**Author:** ![Exapno\_Mapcase](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/exapno_mapcase/32/1051_2.png) [@Exapno\_Mapcase](https://boards.straightdope.com/u/Exapno_Mapcase)\ **Post date:** [September 25, 2014, 1:29am UTC](https://boards.straightdope.com/t/so-black-holes-dont-exist-now/699470/12 "2014-09-25T01:29:58Z")
> [@njtt](#): > > What do you mean by “seen” in that sentence. I think what you mean is “inferred” from certain measurements (very likely manifest as a numerical printout), via a lot of theory and some quite complex math. This is what I meant, but as a professional writer I used one word instead of twenty. 🙂 ---
**Author:** ![Andy\_L](https://avatars.discourse-cdn.com/v4/letter/a/c67d28/32.png) [@Andy\_L](https://boards.straightdope.com/u/Andy_L)\ **Post date:** [September 25, 2014, 1:40am UTC](https://boards.straightdope.com/t/so-black-holes-dont-exist-now/699470/13 "2014-09-25T01:40:43Z")
> [@eschereal](#): > > Gottfried Leibniz invented the (use of) squiggly lines, and was kind of concurrent with Issac Newton as far as the overall methodology. Newton used some sort of “dot notation” that never became popular. Dot notation is still in use in mechanical and electrical engineering. ---
**Author:** ![robert\_columbia](https://avatars.discourse-cdn.com/v4/letter/r/e79b87/32.png) [@robert\_columbia](https://boards.straightdope.com/u/robert_columbia)\ **Post date:** [September 25, 2014, 1:56am UTC](https://boards.straightdope.com/t/so-black-holes-dont-exist-now/699470/14 "2014-09-25T01:56:07Z")
[QUOTE=Benios, 2014] …The paper, which was recently submitted to ArXiv, an online repository of physics papers that is not peer-reviewed, offers exact numerical solutions to this problem and was done in collaboration with Harald Peiffer, an expert on numerical relativity at the University of Toronto… [/QUOTE] It’s not being published in a peer reviewed journal, or even being presented at a legit conference. In other words, it’s not Real Science ™. Also, black holes really suck. ---
**Author:** ![cmyk](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/cmyk/32/3353_2.png) [@cmyk](https://boards.straightdope.com/u/cmyk)\ **Post date:** [September 25, 2014, 2:15am UTC](https://boards.straightdope.com/t/so-black-holes-dont-exist-now/699470/15 "2014-09-25T02:15:24Z")
One thing that struck me is the article seems a little disingenuous, in that it omits theories that can account for some of the paradoxical nature arising from black holes, like [Susskind’s Holographic Principal](http://en.wikipedia.org/wiki/Holographic_principle) in regards to “information loss.” [QUOTE=From the [phys.org](http://phys.org) article] The reason black holes are so bizarre is that it pits two fundamental theories of the universe against each other. Einstein’s theory of gravity predicts the formation of black holes but a fundamental law of quantum theory states that no information from the universe can ever disappear. Efforts to combine these two theories lead to mathematical nonsense, and became known as the information loss paradox. [/QUOTE] ---
**Author:** ![Isilder](https://avatars.discourse-cdn.com/v4/letter/i/cc9497/32.png) [@Isilder](https://boards.straightdope.com/u/Isilder)\ **Post date:** [September 25, 2014, 4:58am UTC](https://boards.straightdope.com/t/so-black-holes-dont-exist-now/699470/16 "2014-09-25T04:58:12Z")
"Conservation of information " ? What ? where does that idea come from ? Well its not like information is conserved elsewhere… its not like a “conservation of energy/matter”… Nothing could be known about the insides of the blackhole…and they only exist where “the laws of physics breaks down” . There’s no predicting what the result of a break down of the laws of physics will be… The laws of physics allow us to predict… If we could predict the insides of a black hole, then the laws of physics still apply… the laws told us a prediction, they still hold !. The problem is the complete lack of information about the insides of dark patches. Meanwhile, they talk of dark matter and dark energy. Whats to say that a black hole isn’t just dense dark matter ? Matter which does not emit light… Matter which explains the gravity of a galaxy… I thought that was black holes… now its dark matter… I guess dark matter is the new name for the old concept… “the centre of the galaxy appears to be very dense, but not correspondly brighter”. How to tell the difference between dark matter and a black hole ? If some insubstantial particle or wave, eg neutrino’s, gravity waves could be traced … eg by their path through ? but then they’d have to make light somehow… in order to show there path… some environment where their path shows up like bubbles in a bubble chamber… ---
**Author:** ![njtt](https://avatars.discourse-cdn.com/v4/letter/n/ecd19e/32.png) [@njtt](https://boards.straightdope.com/u/njtt)\ **Post date:** [September 25, 2014, 5:17am UTC](https://boards.straightdope.com/t/so-black-holes-dont-exist-now/699470/17 "2014-09-25T05:17:23Z")
> [@Exapno\_Mapcase](#): > > This is what I meant, but as a professional writer I used one word instead of twenty. 🙂 The connotations of ‘seen’ and ‘“inferred” from certain measurements (very likely manifest as a numerical printout), via a lot of theory and some quite complex math’ are vastly different. ‘Seen’ implies that there is really no room for any doubt about it, and opinions are most unlikely ever to change. What I said brings out the reality that there is actually enormous scope for reasonable doubt on all sorts of grounds, and opinions are quite likely to change. No, nobody has ever _seen_ black holes at the center of galaxies. What have been considered our best theories, up until now, _imply_ that they should be there, but what are considered our best theories changes all the time, and the whole point of this thread is that the theories relevant to black holes may be in the process of changing right now. ---
**Author:** ![njtt](https://avatars.discourse-cdn.com/v4/letter/n/ecd19e/32.png) [@njtt](https://boards.straightdope.com/u/njtt)\ **Post date:** [September 25, 2014, 5:20am UTC](https://boards.straightdope.com/t/so-black-holes-dont-exist-now/699470/18 "2014-09-25T05:20:57Z")
> [@robert\_columbia](#): > > It’s not being published in a peer reviewed journal, or even being presented at a legit conference. In other words, it’s not Real Science ™. Neither peer reviewed publication nor conference presentation have any bearing on the question of whether a scientific claim is actually true or false. ---
**Author:** ![Knorf](https://avatars.discourse-cdn.com/v4/letter/k/58956e/32.png) [@Knorf](https://boards.straightdope.com/u/Knorf)\ **Post date:** [September 25, 2014, 5:26am UTC](https://boards.straightdope.com/t/so-black-holes-dont-exist-now/699470/19 "2014-09-25T05:26:07Z")
It’s like a movie not being screened for critics: never a good sign. Also, many or maybe even most scientific papers, including those exhaustively peer-reviewed and vetted, turn out substantially or even entirely incorrect. This story has B.S. written all over it. We can safely continue accepting that black holes exist. ---
**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:** [September 25, 2014, 7:15am UTC](https://boards.straightdope.com/t/so-black-holes-dont-exist-now/699470/20 "2014-09-25T07:15:35Z")
> [@njtt](#): > > The connotations of ‘seen’ and ‘“inferred” from certain measurements (very likely manifest as a numerical printout), via a lot of theory and some quite complex math’ are vastly different. ‘Seen’ implies that there is really no room for any doubt about it, and opinions are most unlikely ever to change. What I said brings out the reality that there is actually enormous scope for reasonable doubt on all sorts of grounds, and opinions are quite likely to change. > > No, nobody has ever _seen_ black holes at the center of galaxies. What have been considered our best theories, up until now, _imply_ that they should be there, but what are considered our best theories changes all the time, and the whole point of this thread is that the theories relevant to black holes may be in the process of changing right now. This sounds a whole lot like the ‘you weren’t there!’ argument that creationists are so fond of. Everything is ‘inference’. Everything. [Next page](https://boards.straightdope.com/t/so-black-holes-dont-exist-now/699470.md?page=2)