Far out cosmology: LeMaitre on origin of universe (Introduction)

by David Turell , Friday, February 03, 2023, 20:00 (657 days ago) @ David Turell
edited by David Turell, Friday, February 03, 2023, 20:10

From an interview:

https://arxiv.org/pdf/2301.07198.pdf

"Georges Lemaˆıtre (1894-1966) was a Professor of Physics
at the Catholic University of Leuven and a Roman Catholic priest. He is widely known as being among the firsts to formulate a theory of the Big Bang. He has also independently attributed the observed recession of nearby galaxies to an expanding Universe. Georges Lemaˆıtre is undeniably one of the key physicist of the XXth century and an important figure of the history of astronomy (Lemaˆıtre 1927; Lemaˆıtre & Eddington 1931; Lemaˆıtre 1931). A video interview of Georges Lemaˆıtre talking about his work is a historical gem. As such, we aim to make this recording as accessible as possible for the astronomy community, and the general public at large.

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"It is that Fred Hoyle, in presenting his Steady State theory, implies that the whole universe satisfies a group, a particular group, which satisfies space as a whole. Maybe it could be explained more clearly. It could be explained more clearly by saying this: a very long time ago, before the theory of the expansion of the universe (some 40 years ago), we expected the universe to be static. We expected that nothing would change. It was an a priori idea that applied to the whole universe...

***

"GLM: You remember, he said that when he started this theory, he thought he had to reject it. The expression he wrote down: ”well nothing much happens, nothing much happens” [...] because, he said, there should be creation. What does this mean... creation ? This word, creation, brings with it a whole philosophical or religious resonance that has nothing to do with the question. Behind this word, creation, what is there? There is simply that the apparition of hydrogen, as Hoyle supposes, is something quite fantastic and unexpected. That’s why he used the word creation. It is absolutely unexpected. And if I had to use another imagery to express the same thing, I would say that this hydrogen appears in a totally unexpected way like a ghost [dramatic emphasis on the word "ghost"].

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"In fact, Hoyle recognizes that there are many theories that he calls ”Big Bang theory”, right. I don’t know to what extent the arrows he shoots against these theories are actually hitting the mark. But as far as the oldest of these theories is concerned, the one I proposed in 1931 under the name of the hypothesis of the primeval atom. I have the impression that his arrows do not reach me at all. I am even a little surprised that he doesn’t realize this,
because we have so often had the opportunity to talk, Hoyle and me, in the most friendly way. If you like, I have the impression that he was mostly concerned with what he imagined the theory to be rather than what it is. Especially the aspect of it that I have developed. So I think that this theory escapes.... ”And quite early on in the game, all the galaxies are supposed to have formed and then should therefore be..” and so on . This is not at all how I have ever considered the theory of the primeval atom. There is a beginning... we may touch on other aspects at some point... there is a beginning very different from the present state of the world, a beginning in multiplicity which can be described in that it can be described in the form of the disintegration of all existing matter into an atom. What will be the first result of this disintegration, as far as we can follow the theory, is in fact to have a universe, an expanding space filled by a plasma, by very energetic rays going in all directions.... Then by a process that we can vaguely imagine, unfortunately we cannot follow that in very many details, gases had to form locally; gas clouds moving with great speeds...

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"JV: Monsignor, does the fact that the universe, according to your theory, has a beginning (at least one beginning)...does it have a religious meaning for you, a religious significance?

"GLM: Well, of course it must be explained... It is quite clear that in these interviews, the use of the word creation has provoked a rather particular turn in these interviews. Each one of them freely, and legitimately, exposed their views... These views were presented rather from the agnostic, materialist, or rather pantheist point of view. I don’t think there would be any interest... any advantage in me opposing these positions that everybody are aware
of... to make a confession of my religious convictions. It wouldn’t make much sense. The point is, to answer your question by dismissing precisely what many people expect, [the point] is that I am not defending the primeval natom for the sake of whatever religious ulterior motive. Ofn course, nobody knows exactly what one’s psychology is, really. But, not only consciously I don’t have this idea at all,n I think that the impact of this theory in the philosophical, philosophicoreligious problem is essentially different. It is a point obviously a little delicate. I am a bit afraid to elaborate on it in a few words now. I elaborated on it extensively in a conference that I gave a few months ago in Namur and that was on your airwaves, but on the French airwaves|| and it is precisely that if my theory is correct, it makes the philosophical problem of creation disappear, in a way."

Comment: offered as an historical, philosophical background perspective from the past.