Other discoveries included in the volume had more to do with careful premeditation than good fortune. The idea for the landmark experiment proving the existence of neurotransmitters came to Otto Loewi in a dream in 1921. "I got up immediately, went to the laboratory, and performed a simple experiment on a frog heart according to the nocturnal design," he wrote years later. Unlike Rutherford and Fleming, Loewi knew exactly what he was out to prove. Scientists had long understood that the nervous system functioned as a kind of telegraph network, sending messages up and down the body. Loewi wanted to understand how nerve cells communicated with one another and how they interfaced with other organs.
His "nocturnal design" involved dissecting two frogs and removing their beating hearts. He bathed both hearts in a saline solution and then electrically stimulated the vagus nerve of one of them, causing it to beat slower. Next, he poured the saline solution from the slowed heart onto the second heart. It started beating slower as well, proving that some chemical had been released into the solution. Eventually, Loewi helped identify that chemical as acetylcholine, one of several neurotransmitters that allow nerves to communicate across the miniature chasms that separate them. To this day, his profoundly simple experiment is considered a model of scientific elegance.
But as beautiful as the experiment may have been, can we really call the paper describing it a work of art? Lightman seems to suffer from an insecurity that afflicts many scientist writers, a compulsion to compare the process of scientific discovery to that of artistic creativity, and to hold scientific and artistic genius up to each other.
The comparison of science and art is a trope that runs through much of Lightman's writing. In The Discoveries he writes that "Einstein was an artist as much as a scientist." What does that really mean? In what sense were Einstein's discoveries art--or for that matter any of the original papers Lightman has collected--except in the most meaningless stretch of metaphor?
Making scientists into artists is a way of dealing with a conundrum that Lightman confronts in A Sense of the Mysterious, a collection of essays published last year: that even the most brilliant scientist is, in some basic way, replaceable. Lightman describes the sense of bewilderment he felt after discovering he'd been scooped by another physicist on a discovery he had spent months working toward. "I began to experience another emotion: irrelevancy. If the physical universe was reducible to precise equations with precise answers...then why was I, as a particular and unique person, needed to find those answers?" After all, if it hadn't been Watson and Crick who discovered the structure of DNA, it would have been Linus Pauling soon after, or someone else. If science advances toward its ultimate objective description of the universe regardless of the individuals who are at its cutting edge, then why celebrate scientists at all? In the same essay, Lightman writes that "the most important thing about a scientific result is not the scientist who found it but the result itself.... In the arts, the individual is the essence." Calling something a work of art and its creator an artist is a form of praise, but more important, it is a way of assigning agency to the people who make the great breakthroughs. It is a way of making them irreplaceable. But sometimes a great discovery is just a great discovery.