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Thread: Praguenosis in Vienna for Possible Hubble-Lemaitre law

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    Praguenosis in Vienna for Possible Hubble-Lemaitre law

    [I wonder how many will get the title wording?]

    The 499th Astronomy Cast podcast has just addressed the new forthcoming vote at the IAU in Vienna regarding the possibility of giving partial credit to Abbe G. Lemaitre for the discovery. [The voting method itself for the IAU has changed, too.]

    So the following is my finger in this big pie:

    The majority of this comes from a paper by Harry Nussbaumer (Inst. of Astronomy, Zurich).

    1912 – Vesto Slipher obtains some of the first redshifts for galaxies. [I wonder how close he came to freezing while getting that data?]

    1917 – Beginning of modern cosmology. Einstein publishes “Cosmological consideration on the general relativity). He applied GR to the entire universe. But he felt that theory should support the established Static Theory for the immutable universe. His cosmological constant was introduced to counter gravity.

    1917 – A few months later, Willem de Sitter published his alternative model, also representing a static model. This was a simplified model that excluded matter, thus not acceptable to Einstein who in 1923 noted that two particles would rush apart from one another because of the cosmological constant, no doubt.

    1922 – Friedman publishes his “About the curvature of Space” based on GR. He held to Einstein’s isotropic view but made R, the radius, variable with time, unlike Einstein and de Sitter’s model. Density, would, therefore, also be variable. ["He did not connect this finding to astronomical observations, and he did not spot the flaw in de Sitter's model." -- Nussbaumer and Bieri (2012).]

    It is noteworthy that de Sitter's model had time varying throughout the universe, which explains his redshift result without motion (so no Doppler effect, which later came with others but now is seen differently). Einstein didn’t initially accept Friedman’s math due to an error on Einstein’s part, but he never accepted the physical significance of Friedman’s work. Thus, Friedman was taken as purely theoretical.

    1925 – Lemaitre showed that de Sitter’s model violated homogeneity, as held by Einstein and himself. Also, Lemaitre treated universe as Euclidian, apparently unbeknownst to Einstein in 1932. [Also, Friedman dies of Typhus.]

    1926 – Hubble determines distances to extragalactic nebulae, that he won't call "galaxies".

    1927 – Independently of Friedman, Lemaitre also had radius and density to vary with time. Unlike Friedman, however, he spotted the weakness of de Sitter’s model that lacked spatial homogeneity.

    Lemaitre concluded that extragalactic nebulae would exhibit redshifts in the form of v = H*d, though H wasn’t for Hubble but expansion, interestingly.

    He knew of Hubble’s distances and he had Slipher’s redshifts. Though the uncertainties were great, Lemaitre postulated an expanding universe.
    He published in 1927 in French and in a little known Belgian scientific journal.

    A few months later, at the Solvay conference, he gave a reprint to Einstein, who considered it to be abominable. [I've seen some quotes where Einstein praised the math but thought the physics was abominable.] But, during the conference, Lemaitre visited with Einstein in a taxi ride to a laboratory and realized Einstein wasn’t informed about the astronomical facts. This didn’t sway Einstein, however.

    I believe it was at this same conference where Hubble had time to visit with de Sitter and learn that redshift wasn't necessarily due to motion, at least in de Sitter's model from Einstein's field equations (but without mass).

    1929 -- Hubble published findings that there was probably a linear relationship between nebular distances and redshifts. Apparently, he wasn’t aware of Lemaitre’s prior claim of this. But note that Hubble is not calling for an expanding universe.

    1929 – Fritz Zwicky proposes the Tired Light explanation for redshift.

    1930 – de Sitter, at the RAS meeting, confirmed Hubble’s work. Eddington and de Sitter were at a loss on how to explain the evidence. [de Sitter has redshift with no expansion, no homogeneity and no mass; Einstein has homogeneity and mass but no explanation for redshift.] Lemaitre read the minutes of the meeting, including the puzzlement, and immediately sent two reprints of his 1927 paper to Eddington, requesting he send the other copy to de Sitter.

    Both Eddington and de Sitter quickly accepted Lemaitre’s model. Eddington publicly acknowledges this in 1930 in the Monthly Notices.

    1930 (June) – Einstein visits Eddington and likely became updated on the observational and theoretical status of cosmology.

    1931 – In Einstein’s trip to Pasadena, there is no mention of Hubble anywhere in his diary, though it is known they met. Einstein’s unifying field views seem to have been foremost on his mind. Seeing the spectral plates seems to have been more a tourist attraction for Einstein. Unlike Tolman, Hubble was not fluent in German and was also reluctant to talk theory. Hubble, in his letter to de Sitter, stated that interpretations “should be left to you and the very few others who are competent to discuss the matter (redshift and distance correlations) with authority.” Hubble avoided the cosmological implications of his findings.

    It seems Einstein was already up to date on Slipher’s and Hubble’s work and may have felt little need to hear it directly as it would be redundant, possibly.

    The age for the universe was approximated to about 10 billion years, but stars were soon determined to be about 100 times older than this; older than the universe. This added no encouragement for Einstein to fully accept any expanding model.

    Lemaitre proposed an early stagnation period followed by an accelerated expansion due to the cosmological term of Einstein which would have greater effect as the universe became less dense.

    1931 -- Hubble and Humason publish new results with 10x the amount of data.

    1931 (March) -- Lemaitre translates his Belgium (French) paper but, with Hubble's great data, he leaves out his expansion calculations. But why? Lemaitre could have corrected his calculations with the new data, but this would be a revision and not a simple translation. He may have elected to honor Hubble for his great achievement in redshift results, perhaps realizing that Hubble never in the 38 page paper mentions the word expansion, leaving room for credit to the theorists like him.

    1931 (March) – Einstein reviews Friedman work and, on the last pages, “Friedman presents his periodic model with lambda = 0. In addition, Lemaitre’s 1927 paper provided the connection between the increasing radius of curvature and the redshifts in the spectra.”

    1931 (June) – Joined with Tolman in a paper that lambda is unnecessary in an expanding universe. Tolman seemed to want to hold on to the cosmological constant, however, and both Eddington and Lemaitre agreed that this constant might be an important force in nature.

    1932 – At the IAU, Eddington and Lemaitre opposed the banishment of lambda.
    Last edited by George; 2018-Sep-13 at 09:46 PM. Reason: grammar
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    Great summary!

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    Another factor that would certainly enter into (say) my vote has been the uncovering of how strongly Hubble wanted to put a personal and institutional brand on the whole redshift-distance discovery. A letter to de Sitter (quote by Block) includes “I consider the velocity-distance relation, its formulation, testing and confirmation, as a Mount Wilson contribution and I am deeply concerned in its recognition as such”, which by our standards is a considerable reach given the formulation from theory (and the role of Slipher's redshift data at the outset).

    A lasting lesson, related to laws of eponymy - discoveries are often much messier and more gradual than hindsight makes them look, especially if we are accustomed to the practice of putting one or two names on a law or principle. I've come to favor descriptive names, maybe with additional people's names. (But still, Kepler and Leavitt)

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    Quote Originally Posted by Strange View Post
    Great summary!
    Thanks, but most of this comes from the Nussbaumer paper. I have read several books on the history behind Big Bang, as well as, Hubble's book. I find this paper does a nice summary job. I thought it might be fitting to get forum discussions on it prior to any voting since it is so interesting even for laypersons like me.
    Last edited by George; 2018-Sep-13 at 10:18 PM.
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    Quote Originally Posted by ngc3314 View Post
    Another factor that would certainly enter into (say) my vote has been the uncovering of how strongly Hubble wanted to put a personal and institutional brand on the whole redshift-distance discovery. A letter to de Sitter (quote by Block) includes “I consider the velocity-distance relation, its formulation, testing and confirmation, as a Mount Wilson contribution and I am deeply concerned in its recognition as such”, which by our standards is a considerable reach given the formulation from theory (and the role of Slipher's redshift data at the outset).
    I'm unclear just what Hubble is saying. His obvious correlations shouldn't exist in the de Sitter universe, but there were others that introduced models that were favorable and similar to Lemaitre, though Lemaitre was first. Weyl, Robertson(?) and a few others come to mind.

    Did Hubble fear he might be seen as being on the sideline since he wouldn't endorse any theory that would greatly enhance the merit of his great data? Also, I can't help but think that the "Great Debate" of 1920 between Shapley and Curtis contributed to his reluctance. It was Hubble that produced the great extragalactic evidence for galaxies but he avoided being in that debate, IIRC.

    A lasting lesson, related to laws of eponymy - discoveries are often much messier and more gradual than hindsight makes them look, especially if we are accustomed to the practice of putting one or two names on a law or principle. I've come to favor descriptive names, maybe with additional people's names. (But still, Kepler and Leavitt)
    Yep, Stigler's law comes to mind when it comes to people.
    Last edited by George; 2018-Sep-13 at 10:18 PM.
    We know time flies, we just can't see its wings.

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