October 16, 2007


A 1949 composite picture with Robert Herman on the left, Ralph Alpher on the right, and George Gamow in the center, as the genie coming out of the bottle of "Ylem," the initial cosmic mixture of protons, neutrons, and electrons from which the elements supposedly were formed. [AIP]

I was pursuing my latest issue of American Scientist and happened across the rather unusual photograph shown above. It depicts George Gamow pioneering cosmologist, rising vaporuously from a bottle of primordial liqueur. 'Ylem' is

a term which was used by George Gamow, Ralph Alpher and their associates in the late 1940's for a hypothetical original substance or condensed state of matter, which became subatomic particles and elements as we understand them today. It reportedly comes from an obsolete Middle English philosophical word that Gamow came across while thumbing through a dictionary, which means something along the lines of "primordial substance from which all matter is formed", and derives from the Greek hylem, "matter". Restated, the Ylem is what "thing" Gamow, et al, presumed to exist immediately after the Big Bang. Along with the ylem, there were assumed to be a large number of high-energy photons present, which we would still observe today as the cosmic microwave background radiation.

Despite the invention of this term in an era before the early universe was well-studied I don't see why it isn't used anymore. Instead, the matter right after the big bang is described in descriptive but dry terms such as 'quark-gluon plasma' or just plain lousy ones like 'primordial soup.' Over these competitors it has many advantages: it is unique and memorable; it is a stand-alone term with no sub-words that people may not fully know (such as 'plasma' or 'soup'); it is four letters long, as opposed to being a lengthy phrase; it is not clear how it should be pronounced. I found a few papers back in the 80's that used the word, but none in more recent decades (I wonder if they were worried about being taken seriously...). Gamow seemed to think (at least for a while) that the Ylem was mostly neutrons, but updated science shouldn't stop us from using a perfectly good Middle-English word, obviously the intended meaning is that of the universe's initial composition. Full stop. That is the kind of word cosmologists could use, if only to frighten and confuse civilians with our unorthodox use of the letter 'y.'

The bottle depicted above is kept under glass in some kind of display in the Smithsonian Institution. Replicas are also available to professors I know (that one at the bottom), it would seem.

P.S.: Gamow was well known for his sense of humor. One oft-repeated tale is of how he tacked Hans Bethe's name onto a paper that Bethe had nothing to do with simply so the byline would read "Alpher, Bethe, Gamow" as a pun on the Greek alphabet. Bethe actually was made aware of the paper and contributed a bit to subsequent work, but this has to remain as one of the most whimsical paper authorships (as well as the most blatantly unethical), especially since the Alpher-Bethe-Gamow theory became well-known enough to be referred to in that way. Robert Herman (pictured above) was not interested in being included under the name 'Delter.' The theory was later found to be lacking in several key ways, but this work was important in the development of Big Bang nucleosynthesis, Gamow's comedy stylings aside. Amusingly, the only person who never got the joke was Alpher himself, who was resentful of sharing credit for his work with the more eminent Bethe (Alpher was an unknown PhD student at the time and was rightly concerned about being overshadowed). As late as a few years ago he was still expressing disapproval.

P.P.S.: Thanks for this inexplicable photograph flickr!

[Photo credit AIP and Snapshotartifact.org]