Friday, February 24, 2023

More scientific discovery as dreaming and serendipity

Archimedes in his bathtub; Newton under an apple tree. We prefer to see these brief oments of serendipitous inspiration as the engines of mathematical and scientific discovery. It's romantic to think so; and so much more preferable than to harp on the importance of long, hard years of knowledge acquisition and failed or inconclusive experiments.


As Rivka Galchen, for example, has written
:

I wonder if we can really teach someone to be a biologist. I mean, sure, we can say, This is what a cell is, and here’s this thing called RNA, and here’s this thing called DNA, and here’s this technique called agarose gel electrophoresis that will separate your DNA and RNA fragments by size — but will teaching really produce the next Charles Darwin or Rachel Carson or Francis Crick? A real scientist follows her own visionary gleam. Penicillin was discovered when Alexander Fleming returned to his messy lab after a long vacation and made sense of a moldy petri dish most people would have thrown out as contaminated. The structure of the benzene ring came to the chemist Friedrich August Kekule after a daydream about a snake biting its own tail. You can’t teach that kind of dreaming. [Emphasis added]

Science as gleams and dreams. It takes only a milligram of skepticism to identify two highly questionable claims here, and only a moment of Googling around to see whether it's justified.

As this archived excerpt from 
Wikipedia explains, returning to the messy lab was only the first step in "discovering" penicillin, and the "sense" that Fleming made of his mold was rather preliminary:

Fleming recounted that the date of his discovery of penicillin was on the morning of Friday, September 28, 1928. It was a fortuitous accident: in his laboratory in the basement of St. Mary's Hospital in London (now part of Imperial College), Fleming noticed a Petri dish containing Staphylococcus plate culture he mistakenly left open, was contaminated by blue-green mould, which formed a visible growth. There was a halo of inhibited bacterial growth around the mould. Fleming concluded the mould released a substance that repressed the growth and caused lysing of the bacteria. He grew a pure culture and discovered it was a Penicillium mould, now known to be Penicillium notatum. Charles Thom, an American specialist working at the U.S. Department of Agriculture, was the acknowledged expert, and Fleming referred the matter to him. Fleming coined the term "penicillin" to describe the filtrate of a broth culture of the Penicillium mould. Even in these early stages, penicillin was found to be most effective against Gram-positive bacteria, and ineffective against Gram-negative organisms and fungi. He expressed initial optimism that penicillin would be a useful disinfectant, being highly potent with minimal toxicity compared to antiseptics of the day, and noted its laboratory value in the isolation of Bacillus influenzae (now Haemophilus influenzae). After further experiments, Fleming was convinced penicillin could not last long enough in the human body to kill pathogenic bacteria, and stopped studying it after 1931. He restarted clinical trials in 1934, and continued to try to get someone to purify it until 1940. [Emphasis added.]

And as this second Wikipedia excerpt makes clear, the supposed daydream was only a small step in the process--and a highly questionable one at that, with a possible origin in parody. When Kekulé spoke of how he came up with his theory

He said that he had discovered the ring shape of the benzene molecule after having a reverie or day-dream of a snake seizing its own tail (this is a common symbol in many ancient cultures known as the Ouroboros or Endless knot). This vision, he said, came to him after years of studying the nature of carbon-carbon bonds. This was 7 years after he had solved the problem of how carbon atoms could bond to up to four other atoms at the same time. It is curious that a similar, humorous depiction of benzene had appeared in 1886 in the Berichte der Durstigen Chemischen Gesellschaft (Journal of the Thirsty Chemical Society), a parody of the Berichte der Deutschen Chemischen Gesellschaft, only the parody had monkeys seizing each other in a circle, rather than snakes as in Kekulé's anecdote. Some historians have suggested that the parody was a lampoon of the snake anecdote, possibly already well known through oral transmission even if it had not yet appeared in print. (Some others have speculated that Kekulé's story in 1890 was a re-parody of the monkey spoof, and was a mere invention rather than a recollection of an event in his life. [Emphasis added.]

And as the New York Times itself reported over 25 years ago:

[A]t least one historian now believes that Kekule never dreamed the snake dream, and that, in any case, the benzene ring had already been described by other chemists at the time Kekule claimed to have discovered it. That is the conclusion of Dr. John H. Wotiz, a professor of chemistry at Southern Illinois University who has made an exhaustive study of the documents and lore Kekule left to his scientific heirs. [Emphasis added.]

Of course, it takes less than a milligram of skepticism to realize that we shouldn't treat fiction writers like Galchen as our primary sources for the history of science. But when a highly articulate writer repeats, in such a highly visible forum as the New York Times, ideas that are already popular misperceptions, particularly ones that resonate so fully with today's education trend-setters, those misperceptions become all the more convincing, and the misguided practices they foster, all the more entrenched.

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