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The primeval atom et The accelerating universe

Journal Entry: Thu Aug 9, 2012, 10:08 PM

Albert Einstein was caught up with the idea of a static and eternal universe. Gravitation however causes all matter to attract each other with a force in relation to its mass. To prevent the universe from collapsing Einstein added the cosmological constant to his field equations of general relativity.


In 1929 Edwin Hubble formulated the empirical Redshift Distance Law of galaxies which is now known as Hubble's Law. After the observations of the cosmological red shift Einstein referred to his cosmological constant as the "biggest blunder" of his life.



In 1998 Saul Perlmutter, Brian P. Schmidt, and Adam G. Riess discovered through observations of distant supernovae—used as so-called standard candles—that the universe is actually accelerating. This is where the cosmological constant actually becomes relevant again as the equations can be used with a positive value to calculate the acceleration. As it turns out, the universe could never be in perfect equilibrium due to its inherent instability: if the universe expands ever so slightly the expansion releases vacuum energy which causes yet more expansion. Likewise, a universe which contracts slightly will continue contracting. The observations of an accelerating universe were consistent with a cosmological solution which Alexander Friedmann derived from Einstein's original general relativity equations.



This brings me to the reason for writing this article. The way I learned it, Einstein and Hubble were major contributors of the cosmological solution which eventually became the Lambda-CDM model—what is frequently referred to as the standard model of Big Bang cosmology. On a side note, another explanation of the accelerating universe is quintessence, which is a hypothetical form of dark energy and a model which only differs from the cosmological constant in that it's a dynamic equation that changes over time. I would go further into this but I'm afraid it's beyond the scope of this article.



As is often the case in physics, several people are working on the same problems and so it can often be challenging to attribute theories verified by observations to the right people. In fact some of Einstein's ideas were (partly) conceived previously by people completely overlooked.



Although not completely overlooked, Georges Lemaître didn't really get all the credit he deserved until later. This Belgian priest, astronomer and professor of physics at Catholic University of Louvain was the first person to propose the theory of the expansion of the universe, which—as we now know—is widely misattributed to Edwin Hubble. He was also the first to derive what is now known as Hubble's law and made the first estimation of what is now called the Hubble constant. He published this in 1927, two years before Hubble's article. Moreover, Lemaître also proposed the hypothesis of the origin of the universe which became known as the Big Bang theory. This is the notion that the universe came from a single point. He called this the hypothesis of the primeval atom. Incidentally, Lemaître described this theory as "the Cosmic Egg exploding at the moment of the creation" and to his discontent was adapted by Pope John XXIII who took it as proof of the biblical story of Genesis and in complete accordance with the teachings of the Church. After all, in a universe which is infinite and timeless a God as the creator becomes irrelevant.



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:iconraraavisindextra:
RaraAvisInDextra Featured By Owner Aug 28, 2012
Correct me if i'm right but i believe George Gamow was also involved in the making of this so called big-bang theory, though i wonder how could have this "bang" actually sound.
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:iconmartinsilvertant:
MartinSilvertant Featured By Owner Aug 28, 2012  Professional General Artist
I never heard of him before but Wikipedia says he was an early advocate of Lemaître's theory, although I'm not sure what that means exactly. He has a very impressive portfolio though. It's really a pity that these guys are never named prominently. It almost seems it was all about Schrödinger, Einstein, Heisenberg, Oppenheimer and Feynman when talking about physics in the early 20th century.

I never even thought of how the creation of the universe could've sounded. Interesting question.
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:iconraraavisindextra:
RaraAvisInDextra Featured By Owner Aug 28, 2012
I guess it couldn't have sound cause there was no air surrounding it, not even matter nor molecules of any kind of course, but you know: if space ships can make "crash" or "ping-ping-pow" when fighting and exploding in films, why couldn't the whole mass of the universe make "bang" in the beginning, scientific theories and film plots come all from imagination in the end.
Gamow was also the author of several books explaining scientific issues to the common citizen, they're all obsolete of course (the maniac is introduced as the latest novelty in one of them) but it didn't prevented me from reading them as a child, there was some humour which at some point happened to be more bearable than the typical anglo-american irony of some popular authors.
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:iconmartinsilvertant:
MartinSilvertant Featured By Owner Aug 28, 2012  Professional General Artist
I don't know. Of course you need air for the vibrations of sound but I wonder if the expansion of space itself wouldn't form a shock wave to bring over the sound. I'm very much speculating; it may even be dumb and illogical what I'm saying.
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:iconcvcharger14:
cvcharger14 Featured By Owner Sep 4, 2012  Hobbyist Photographer
Hypothetically, if a person could survive being in the vacuum of space, was present prior to the Big Bang, and could survive such a rush of energy, that person could potentially hear the Big Bang. The shock waves from the Big Bang would be carried in the gas clouds that are moving outwards. The sound that would be perceived would come from the gas particles hitting the ear drums. Hmm, I wonder if that means that solar wind could be heard?
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:iconmartinsilvertant:
MartinSilvertant Featured By Owner Sep 4, 2012  Professional General Artist
I was thinking along the same lines, but do you think it would even be in the right frequency for us to hear?
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:iconcvcharger14:
cvcharger14 Featured By Owner Sep 5, 2012  Hobbyist Photographer
I would imagine that it would be in the frequency ranges that are characteristic of hydrogen and helium. But of course with it being an explosion within a vacuum, you would most likely be able to hear a loud rumbling from all of the hydrogen particles being pushed against your ear. I imagine it would sound a lot like a high pitched thunder storm. As for the solar wind, frequency may not be the issue so much as the fact that a solar (or stellar) wind would consist of fewer particles, which have enough energy to move the membrane. From our distance, it certainly would not be loud enough for the human ear to hear.
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