Georges Lemaître, the Belgian priest who discovered the universe is expanding | Hacker News Reader

Georges Lemaître, the Belgian priest who discovered the universe is expanding

independent.co.uk

101 pointsokket23 comments

Lemaitre was also a first-rate geometer. He wrote a paper on quaternions and elliptic geometry (geodesics on a sphere) that was published with a Latin abstract in a journal of the Pontifical Society of the Vatican. My library didn't have a copy, and so that was probably the only time in my life that I had to correspond with the Vatican to get a copy :-)

At first, I read this title as

> Georges Lemaître, the Belgian priest who discovered the universe, is expanding

A subtle, but important, distinction.

But given he is part of the Universe, isn't he also expanding?

As I understand it, the galaxies themselves are not really expanding in-and-of themselves, but moving away from each other.

I suppose, though, that we are all releasing heat and carbon dioxide etc. all the time, and the more space there is for waste and heat to radiate into, the more the source could be said to be "expanding".

Of course, whilst you are alive, you are replenishing these particles, but after you die, you cease to replenish them, and so perhaps it then makes sense to talk about your constituent particles as being as much "you" as that which is still part of the main body mass. And so, as your body is eaten away by bacteria and worms, you are steadily carried across to far flung parts of the earth and beyond.

Thus, as the universe heads towards being an entropic soup, the components will be spread ever further and wider.

So, in conclusion, yes, I suppose Lemaître might be said to be expanding.

I still doubt that he should be credited as discoverer of the universe, though.

Some good beer will definitely cause that after a while

Interestingly, I made the same error. I think because that first comma is misplaced (vs, say, a colon), making me expect a second comma later.

2011 Nobel Prize in Physics was awarded for "for the discovery of the accelerating expansion of the Universe through observations of distant supernovae".

https://www.nobelprize.org/nobel_prizes/physics/laureates/20...

You may well know this, but there is a difference between (mere) expansion and acceleration of the rate of expansion. Lemaître discovered the former, confirmed by Hubble IIRC.

Interestingly the discovery was "abused" for political purposes:

In 1951, Pope Pius XII claimed that Lemaître's theory provided a scientific validation for Catholicism – a claim that Lemaître resented, as he stated his theory was neutral.

It was also disputed on the other side for the same reasons, see https://en.wikipedia.org/wiki/Fred_Hoyle :

> He found the idea that the universe had a beginning to be pseudoscience, resembling arguments for a creator, "for it's an irrational process, and can't be described in scientific terms"

Pope Pius XII at least had the excuse of trying to speak about a field in which he wasn't an expert.

Einstein's initial reaction was the same before he changed his mind.

However, there are two points worth making. First, that something supports or can be used to support religious claims does not undermine that something (evidence, argument, whatever). It would be tendentious to do so. Second, creation as understood in Catholicism is not the same as creation in time. The notion that the universe was created in time was given serious consideration IIRC in the 12th century, but theologians like Aquinas held that it was not metaphysically provable whether the universe was in fact created in time or not. Creation as understood by theologians is creation from nothing, the continuous creation or sustaining of things in existence. I.e., we cannot explain the existence of things at any moment by appealing to anything about these things themselves or to their efficient causes, and so we need to appeal to a cause distinct from them and one which transcends the order of things. While creation in time may appeal to certain sensibilities, it is not itself demanded by Catholic theology.

That was more of a musing on the part of P. Pius XII because he had been preoccupied with the philosophical side of showing God's existence, and saw some potential synergy. In his Un'Ora speech, where he was actively contemplating the primeval atom hypothesis:

...contemporary science, with one sweep back across the centuries, has succeeded in bearing witness to the august instant of the primordial Fiat Lux, which along with the matter there burst forth from nothing a sea of light and radiation... Thus, with that concreteness which is characteristic of physical proofs, modern science has confirmed the contingency of the universe and also the well-founded deduction to the epoch when the world came forth from the hands of the creator

However, before his speech to the Eighth General Assembly of the International Astronomical Union in Rome, Lemaître consulted with the Pope's secretary as well as his science advisor, and Pius's further statements dropped references to the "primeval atom" hypothesis:

the human spirit, upon considering the vast paths traveled by galaxies, becomes in some manner a spectator at the cosmic events that occurred on the very morning of creation

Despite this, it was enough to fuel criticism of concordism (the belief that the Bible contains hidden scientific facts). Lemaître addressed those by invoking a separation of concerns: Philosophy and theology are concerned about the "why?" and science is concerned about the "how?"; the two need not overlap. In his words:

Should a priest reject relativity because it contains no authoritative exposition on the doctrine of the Trinity? Once you realize that the Bible does not purport to be a textbook of science, the old controversy between religion and science vanishes... The doctrine of the Trinity is much more abstruse than anything in relativity or quantum mechanics; but, being necessary for salvation, the doctrine is stated in the Bible. If the theory of relativity had also been necessary for salvation, it would have been revealed to Saint Paul or to Moses... As a matter of fact neither Saint Paul nor Moses had the slightest idea of relativity

More info and actual sources: https://www.catholicculture.org/culture/library/view.cfm?rec...

note that the 'civil' in 'civil engineering' uses the 'not military' meaning of the word. It has nothing to do with https://en.wikipedia.org/wiki/Civil_engineering

From your page

> It is considered the second-oldest engineering discipline after military engineering,[3] and it is defined to distinguish non-military engineering from military engineering.

So not sure what you intended to mean?

I’d guess to differentiate the civil / uncivil dichotomy from the civil(ian) / military dichotomy.

That said, I feel that civil engineering is fairly widely understood to be a subdicipline of engineering.

In the US/UK civil engineering is often taken to mean constructing buildings (very roughly, in a nutshell), whereas other countries (in particular continental Europe) use the meaning that you quote. So you can have a Belgian civil engineer who specializes in theoretical physics, and knows more about the Higgs boson than about "traditional" engineering topics.

In Belgium, there are 'civil engineers' that know nothing about the construction of roads buildings or bridges, but are specialised in electronics, computer science, thermodynamics, ... .

In the case of Lemaitre, he was studying this: https://en.wikipedia.org/wiki/Mining_engineering

Technically it was Friedmann who first theorised that the universe could be expanding, but Lemaître came to the same conclusion independently later.

https://en.wikipedia.org/wiki/Alexander_Friedmann#Professors...

For the full story:

https://en.wikipedia.org/wiki/Friedmann%E2%80%93Lema%C3%AEtr...

A different part of the full story:

http://home.fnal.gov/~skent/blunder.html

Lemaître discovered Hubble's law, though ;)

True, but Lemaître actually calculated the Hubble constant[1], partly using data published by Hubble (but before him).

[1]: http://home.fnal.gov/~skent/blunder.html

Can someone explain how the universe could be expanding if space is intertwined with time. Is spacetime expanding in meta time ?

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