Hubble cleared

Journal name:
Date published:
Published online

A painstaking study absolves US astronomer Edwin Hubble of censoring a Belgian rival.

Edwin Hubble is that relatively rare thing among dead astronomers — a global household name. He owes his status mainly to the NASA space telescope named in his honour. So when researchers suggested this year that Hubble might have censored the work of a rival to secure credit for the groundbreaking discovery that the Universe is expanding, they triggered a fuss that was far removed from the usual arcane wrangling over historical research priority.

In an admirably thorough Comment on page 171, Mario Livio, an astronomer at the Space Telescope Science Institute in Baltimore, Maryland, clears Hubble of wrongdoing. As a result, NASA and a generation of researchers whose careers are closely tied to the Hubble brand can look skywards with some relief.

The charges against Hubble certainly warranted examination. In 1927, the Belgian astronomer Georges Lemaître published a French-language paper in the Annales de la Société Scientifique de Bruxelles that laid out the essentials of a picture of galaxies expanding away from one another, and derived an expansion parameter on the basis of then-recent observations. In 1929, Hubble independently put forward and confirmed the same idea, and the parameter later became known as the Hubble constant. In 1931, Lemaître's paper was translated into English and published in the Monthly Notices of the Royal Astronomical Society, but most English speakers probably learned of Hubble's contribution before they learned of Lemaître's.

Suspicions of foul play emerged earlier this year, when amateur historians noticed that the derivation of the expansion constant is missing from the English translation of Lemaître's work. Knowing that Hubble was concerned that he, and the Mount Wilson Observatory in Pasadena, California, at which he made his observations, should get ample credit for confirming the expansion of the Universe, it was tempting to speculate that he had a hand in the editing of the Belgian's paper. But motive alone doesn't build a case, and professional historians, who had known of the irregularity for years, remained sceptical.

Livio's research suggests that they were right to hesitate. After reviewing hundreds of documents in the archives of the Royal Astronomical Society in London, Livio found a copy of a 1931 letter by Lemaître in which he said that in translating his paper, he had deleted discussion of the velocities of galaxies because it was “of no actual interest”. Why exactly Lemaître thought this is unclear, but it seems that he was not very concerned about getting the credit for his work in the way that modern followers have assumed; instead, he may have worried more about seeming out of date, given that the data on which the expansion constant was based had been improved since 1927.

The idea that the accuracy of papers and their relevance to colleagues ought to be more important than ensuring priority at every step may seem fantastic in today's cut-throat world of science. And perhaps it was then, too. Perhaps Lemaître was simply so flattered to be invited to translate his paper that, aware of Hubble's importance among English-speakers and fearful of repercussions, or eager to join the Royal Astronomical Society, he self-censored. The case against Hubble is closed, but there may still be a story for motivated historians to look into.

Space agencies should also take note. Whether or not Hubble deliberately censored Lemaître, the fact is that in the English-speaking world, Lemaître has lost — to Hubble — priority for his contributions. The Belgian's name is a worthy candidate for the title of a future space mission.


  1. Report this comment #29943

    Christophe Verlinde said:

    The statement in paragraph 3 that Hubble did develop the idea INDEPENDENTLY is not supported by
    the interview with Hubble's assistant Humason on the American Institute of Physics web site. As the web site prohibits quoting I will paraphrase. Humason says that either in '27 or '28 Hubble came back from
    an IAU meeting and reported that a couple of scientists had seen a relationship between distance and redshift.

    Disclaimer: on their web site AIP states:
    Please bear in mind that: 1) This material is a transcript of the spoken word rather than a literary
    product; 2) An interview must be read with the awareness that different people's memories about
    an event will often differ, and that memories can change with time for many reasons including
    subsequent experiences, interactions with others, and one's feelings about an event.

  2. Report this comment #30041

    Neville Woolf said:

    When an idea is in the air, the one who states it is speaking on behalf of humanity.
    One does not find a voice in a vacuum. We all stand on the shoulders of those who
    came before.

  3. Report this comment #30359

    René van Slooten said:

    This is an interesting discussion, but could it not be that Alexander Friedmann, Georges Lemaître and Edwin Hubble all drank from the same source? After all, it was Edgar Allan Poe who first described the Big Bang and the expanding universe in his brilliant essay 'Eureka' (1848). That Friedmann was inspired by Poe is an established fact That Poe was immensely popular and influential in Belgium is also an established fact. So we may safely assume that also Lemaître knew Poe's work. I do not know about Hubble's literary preferences, but why should Poe be absent from his bookshelf?
    Further I find it significant that all four, Poe, Friedmann, Lemaître and Hubble, had solid military backgrounds as experts in ballistics and explosives. So the idea of a Big Bang and an expanding universe must have been quite self-evident to them.

  4. Report this comment #30886

    Eduardo Riaza said:

    In an article from 1957, Robert Merton remarked that ?no scientific discovery is named after its original discoverer?. And that is what has happened with the discovery of the expansion of the universe. However, the issue is not as simple as it seems in an article from the 10th November.
    In 1929, Edwin Hubble established the relationship between distance and recession velocity of galaxies and, although Georges Lemaître came to a similar outcome two years before, one cannot attribute this last discovery to him, as Lemaître did not know the distances of galaxies in 1927, and had to use an average approximation. For this reason, Lemaître never claimed this discovery.
    But the relationship between distance and recession velocity of galaxies is not the same as saying that universe is expanding. In fact, Hubble had two serious difficulties in accepting the expansion of the universe and never claimed this discovery. It was Lemaître who showed, with astronomical data, that a model of the universe in expansion exists, and that model probably reflects the real universe.
    The question that we should ask ourselves is: what is the reason behind Hubble going down in history as the discoverer of the expansion of the universe?
    We find the answer is in the crude simplification of authors and the popularization in the 1950s, when the majority of astronomers and cosmologists who played influential roles in the discovery of the expansion of the universe or in early cosmology in the 1930s were no longer alive.

Subscribe to comments

Additional data