When Dirac was a child, he believed in Santa Claus (Father Christmas). I don't know whether he ever changed his mind.
If Dirac ever wrote such a paper. As you yourself admit, there seems to be no evidence on the internet that he wrote anything about black holes at all.I no longer remember anything about the process of formation of a black hole, so I can't address your above arguments. However, I'm fairly sure that Dirac, when he wrote his 1962 paper, WAS familiar with the way black holes form, and that knowledge didn't keep him from concluding that there is nothing inside the event horizon of a black hole. What I don't know is whether he ever changed his mind about his conclusions in his 1962 paper.
I have been searching too for Dirac papers on the absent of space and time inside the event horizon. I find lots of papers using Dirac spinors when explaining Hawking's Radiation process but no direct mention of no space and time.If Dirac ever wrote such a paper. As you yourself admit, there seems to be no evidence on the internet that he wrote anything about black holes at all.
Did you find any papers actually by Dirac on the subject of black holes?I have been searching too for Dirac papers on the absent of space and time inside the event horizon. I find lots of papers using Dirac spinors when explaining Hawking's Radiation process but no direct mention of no space and time.
Something that did distract me was finding this off topic clip.
'' Brian cox visits the world's biggest vacuum '' NASA.
Bowling ball and feathers falling at same rate from same start point.
Clip Just over 4 minutes long.
Time mark in clip for drop in air 1:15
Time mark in clip for drop in vacuum 2:30
Worth watching whole clip at full screen.
Great argument.Amazing that Dirac had the same opinion I have, isn't it! I think I'm in pretty good company.
So from the frame of the infalling person there is an incredibly strong force pulling you towards the center of the black hole until you reach the event horizon at which point there is a stronger force in the opposite direction? What is this (5th?) force stopping you?They will join the collection of mass that has been accumulating there ever since the black hole came into existence.
Maybe, but anyone who claims that general relativity can describe regions inside the event horizon is correct.Anytone who claims to know what exists, if anything, inside the event horizen of any region of spacetime is presuming to know more than experimental science can ever know.
Sorry, I should have made that clearer. I found no Dirac papers mentioning black holes. The papers I found mentioning Dirac spinors were by other authors and to do with the process of Hawking Radiation.Did you find any papers actually by Dirac on the subject of black holes?
[...] I've tried to find that paper, but haven't been successful. It was published in 1962 [...]
Well there we go.Paul Dirac said:... I feel ...
That's what I suspected.Sorry, I should have made that clearer. I found no Dirac papers mentioning black holes. The papers I found mentioning Dirac spinors were by other authors and to do with the process of Hawking Radiation.
So you believe the inside of a black hole is a different universe? No the antimatter particles that often collide with them are."C C", your above post COMPLETELY solves my problem! Thank you!
That first page of a paper Dirac wrote ("Particles of Finite Size in the Gravitational Field", published Nov 27, 1962 in volume 270, issue 1342 of the Proceedings of the Royal Society, https://royalsocietypublishing.org/doi/10.1098/rspa.1962.0228) contains EXACTLY what I've been looking for. The critical phrase I've been trying to find again is [which I'm highlighting in red]
"so I feel that the space inside the Schwarzchild radius must belong to a different universe and should not be taken into account in any physical theory."
(The "Schwarzchild radius" is the event horizon.)
Well done! Now it all makes sense.Dirac's manuscript was titled "Particles of Finite Size in the Gravitational Field". Published Nov 27, 1962 in volume 270, issue 1342 of the Proceedings of the Royal Society. The term "black hole", of course, wasn't coined until 1968.
https://royalsocietypublishing.org/doi/10.1098/rspa.1962.0228
Paul Dirac: “The mathematicians can go beyond this Schwarzschild radius, and get inside, but I would maintain that this inside region is not physical space, because to send a signal inside and get it out again would take an inﬁnite time, so I feel that the space inside the Schwarzschild radius must belong to a diﬀerent universe and should not be taken into account in any physical theory. So from the physical point of view, the possibility of having a point singularity in the Einstein ﬁeld is ruled out. Each particle must have a ﬁnite size no smaller than the Schwarzschild radius.”
Note that the specific quote above from it was mediated through Abhas Mitra's "Mass of Schwarzschild Black Holes Is Indeed Zero And Black Hole Candidates Are Quasi Black Holes" (May 11, 2018)
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This makes much more sense. And your memory is not bad, after all!"C C", your above post COMPLETELY solves my problem! Thank you!
That first page of a paper Dirac wrote ("Particles of Finite Size in the Gravitational Field", published Nov 27, 1962 in volume 270, issue 1342 of the Proceedings of the Royal Society, https://royalsocietypublishing.org/doi/10.1098/rspa.1962.0228) contains EXACTLY what I've been looking for. The critical phrase I've been trying to find again is [which I'm highlighting in red]
"so I feel that the space inside the Schwarzchild radius must belong to a different universe and should not be taken into account in any physical theory."
(The "Schwarzchild radius" is the event horizon.)
[...]
But Dirac says very clearly there is space inside the Schwarzchild radius. It's just that, in his view, it belongs to a different universe from ours, by which he means it should not be taken into account in any physical theory, due to the impossibility of information transfer across the boundary. That's quite different from what you have been suggesting. Nor does it support your idea of mass accumulating at the edge, stopped from entering by some undefined agency.
It's not just possible: it's quite clearly there.My reading of what Dirac said is different from yours. I think he was saying that OUR universe doesn't include the interior of any black holes, i.e., the volume inside the event horizon. I think he was saying that there is ANOTHER possible universe, independent of, and unconnected with ours, that consists only of the interior of a black hole (or maybe of multiple black hole interiors, and having no spacetime anywhere else. The two universes don't exist simultaneity, and there is no connection between them. I.e., I think Dirac was just saying that Einstein's GR equations ALLOW for an alternate universe (not ours), consisting of the interior of a black hole, or perhaps of multiple black hole interiors.
Hawking radiation reduces the mass and rotational energy of black holes and is therefore also theorized to cause black hole evaporation. Because of this, black holes that do not gain mass through other means are expected to shrink and ultimately vanish. For all except the smallest black holes, this would happen extremely slowly. The radiation temperature is inversely proportional to the black hole's mass, so micro black holes are predicted to be larger emitters of radiation than larger black holes and should dissipate faster.
Dirac's manuscript was titled "Particles of Finite Size in the Gravitational Field". Published Nov 27, 1962 in volume 270, issue 1342 of the Proceedings of the Royal Society. The term "black hole", of course, wasn't coined until 1968.
https://royalsocietypublishing.org/doi/10.1098/rspa.1962.0228
Paul Dirac: “The mathematicians can go beyond this Schwarzschild radius, and get inside, but I would maintain that this inside region is not physical space, because to send a signal inside and get it out again would take an inﬁnite time, so I feel that the space inside the Schwarzschild radius must belong to a diﬀerent universe and should not be taken into account in any physical theory. So from the physical point of view, the possibility of having a point singularity in the Einstein ﬁeld is ruled out. Each particle must have a ﬁnite size no smaller than the Schwarzschild radius.”
Note that the specific quote above from it was mediated through Abhas Mitra's "Mass of Schwarzschild Black Holes Is Indeed Zero And Black Hole Candidates Are Quasi Black Holes" (May 11, 2018)
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What did you mean in your last sentence above? In particular, what did you mean by "mediated" in that sentence?