Schwarzschild Conference, Frankfurt, July 2017, report
In English
August 2, 2017
I just came back from the Karl Schwarzschild conference, held in Germany at the prestigious FIAS, the Frankfurt Institute for Advanced Studies.
I had hesitated a lot about the content of my poster and finally decided to present roughly my system of coupled field equations.
A text didn't fit well with the central theme of the conference, focused on "black hole physics". It's a subject I had intended to address, but the paper I published in 2015 in Modern Physics Letters A:
J.P.Petit & G.D’Agostini:
Cancellation of the central singularity of the Schwarzschild solution with natural mass inversion process .
Mo. Phys. Lett. A
, vol. 30, n°9 (2015)
was the one that came closest to this theme. Since there was a blackboard next to my poster, I therefore wrote the main points of this paper on it:
This immediately attracted attention. Conference attendees took photos and a crowd gathered. A man in his sixties, a "senior researcher", immediately expressed his skepticism about the idea that all the singular aspects of the metric solution found by Schwarzschild in 1916, which serves as the basis for the black hole theory, could be eliminated by a single change of variable. Since he wasn't wearing a badge, like others, I concluded that he must be part of the FIAS, the Frankfurt Institute for Advanced Science, which hosted this conference. Here is this change of variable:
Finally, a critique! To make things even clearer, I quickly put all the details of the calculation on a sheet of paper that I gave to my expert, and he went to check it for fifteen minutes, sitting on a chair.
Everyone waited for his verdict. He finally returned my sheet with a sign of agreement, but with the greatest perplexity. I think he must have said to himself "I have never seen this anywhere. There must be an error that I can't see. But I'll look into it later. "
I tried to get him involved in this problem, which raises the question of the interpretation of Karl Schwarzschild's result in 1916 (the conference was called "Karl Schwarzschild Conference"!). I asked him if he had read the original article published in the Annals of the Prussian Academy of Sciences:
K.Schwarzschild:
Über das Gravitational eines Massenpunkets nach der Einsteineschen Theory.
Stizber. Preuss. Acada. Wiss. Berlin
, p.189–196 (13 Jan.1916). English version by S.Antoci and A.Loinger at
arXiv:physics/9905030
(12 May 1999)
as well as the second article, published a few weeks later, only a few months before his death:
K.Schwarzschild:
Über das Gravitationsfeld einer Kugel aus incompressibler Flüssigkeit nach Einsteinsechen Theorie
.
Preuss. Acada. Wiss. Berlin
, p.189–196 (24 feb.1916). English version by S.Antoci at
arXiv:physics/9912033
(16 Dec. 1999)
He admitted he had never read them (...) adding:
Do you read German?
No, I just had access to relatively recent English translations (1999) for documents now a century old. I have these documents on my phone. Would you like us to look at them together? There is also a very important text that David Hilbert published in December 1916, in which he re-examines Schwarzschild's work.
D.Hilbert:
"Die Grundlagen der Physik (Zweite Mitteilung)"
(EN)
"The Foundations of Physics (Second Communication)"
(FR) "Les Fondements de la Physique (Seconde Communication)"
He preferred to avoid the topic, adding that he also didn't know that other text (...).
In fact, what I could realize in Frankfurt is that black hole men simply don't know the founding texts from which the works they intend to develop were conceived. During a masterful lecture, in front of all the conference participants
Juan Maldacenua
, a "figure" in the developments of modern black hole theory, began by saying (it is reproduced in the brochure published for the conference)
Juan Maldacena
- The Schwarzschild solution has confused us for over a hundred years and it has forced us to sharpen our views on space and time. It has lead to a sharper understanding of Einstein’s theory. Experimentally, it is explaining several astrophysical observations. Its quantum aspects have been a source of theoretical paradoxes that are forcing us to understand better the relation between spacetime geometry and quantum mechanics.
Translation:
The Schwarzschild solution has been a source of confusion for a century and has forced us to refine our understanding of space and time. This has led to a better understanding of Einstein's theory. On the experimental level, it explains a number of astrophysical observations. Its quantum aspects have been a source of theoretical paradoxes that are forcing us to better understand the relationship between spacetime geometry and quantum mechanics.
What does this concretely mean?
First, there was the "discovery" of "Hawking radiation". In fact, all of this is based on the idea of a marriage between General Relativity and Quantum Mechanics. But we know that ... this union has never been consummated (gravity stubbornly refuses to be quantified, which would lead to the description of a graviton, a spin 2 particle, which has never been found).
Our modern theorists have finally convinced themselves that this fantasy has the value of reality. Indeed, it is by invoking a quantum phenomenon near the black hole horizon that Hawking "showed" that they could lose energy, "radiate". This immediately gave rise to the "cosmic horizon paradox". Indeed, in these objects called black holes, all structure would be supposed to disappear, to be crushed. Therefore, black holes would be "information destruction machines". Maldacena then explained the progress made regarding the "thermodynamics of black holes". He particularly recalled "that it had been shown that the entropy of black holes is proportional to their area".
In short, since the last decades, all the attention of theorists has been focused on how to circumvent this information paradox. You have certainly heard of a "firewall" and other things of this kind. In his latest works, Maldacena invokes a new "key term": "entanglement" ("Intrication"). A concept from quantum mechanics and the famous Einstein-Podowlski-Rosen paradox (EPR paradox) that I described in my video
JANUS 6
( at 14' 04"). It is in this experiment that the two emitted photons are "entangled". In short, according to Maldacena, "entanglement" provides all the answers. This, plus a dash of string theory.
This speech represents the peak of theory in 2017.
The conference participants obviously referred to the JANUS videos (see the PDF list of
their
contents
). Thanks to the enormous work done by Julien Geffray, six videos were equipped with this subtitles at the opening of the conference, the JANUS 14 to JANUS 19. And it is there that we realize that this good English subtitles are something
absolutely essential.
It is impossible to provide poor quality: internet users would immediately switch. Geffray, who has followed my work for 20 years, and who fully masters the language of Skhaespeare, was the only one who could carry out this delicate subtitling work, at the rate of 3 days of full work per video. This represents 15,000 to 20...