Charles Darwin, Linus Pauling, and Albert Einstein made great contributions to science. They also made large blunders. In this original essay Mario Livio, astrophysicist at the Space Telescope Science Institute, and author of the new book Brilliant Blunders: From Darwin to Einstein - Colossal Mistakes by Great Scientists That Changed Our Understanding of Life and the Universe, describes three blunders, and why these great minds made them. -- Mark
When James Joyce wrote in Ulysses: “A man of genius makes no mistakes. His errors are volitional and are the portals of discovery,” he meant the first part of the statement to be provocative. History has shown us that even some of the greatest scientific luminaries, towering figures such as the naturalist Charles Darwin, the twice-Nobel-Laureate chemist Linus Pauling, and the embodiment of genius — Albert Einstein — have made some serious blunders.
In Darwin’s case, he did not realize that with the theory of heredity prevailing at his time, natural selection simply could not work. Basically, the then-held belief stated that the characteristics of the two parents become physically blended in their offspring, just as in the mixing of paints, or of gin and tonic. If that were true, however, then any variation would have been inevitably lost, as all the extreme types would have vanished rapidly into some intermediate mean. Imagine, for instance, a population of one thousand white cats and one black cat. Additionally, suppose that being black confers some evolutionary advantage. In the “paint-pot theory,” the first offspring of the black cat with a white partner would be gray, and continuous mating with white cats would result in increasingly paler shades of gray. There was no way for the black cat to turn the entire population black after many generations, no matter how advantageous the black color might have been, contrary to Darwin’s vision of evolution by means of natural selection.
The solution to this problem came in the form of Gregor Mendel’s particulate genetics. In categorical contrast to blending, Mendel’s theory stated that the genes are discrete entities that are passed on unchanged to the next generation. In this sense, genetics resembles the shuffling together of two decks of cards rather than the mixing of paints — a Jack remains a Jack, no matter how many times you shuffle.
Continuing on the topic of life on Earth, Linus Pauling’s blunder concerned an ill-fated model for DNA. Having previously had enormous success in deciphering the structure of proteins, Pauling turned his attention to DNA in earnest only in November of 1952. Yet, just about one month later, he already came up with what he considered a viable model for the molecule. His model contained three helical strands (as opposed to the later, correct model by Watson and Crick, which was a double helix), was built inside-out, and was patently unstable because all the negative charges were concentrated at its center and would have driven the structure apart. How was it possible that the world’s greatest chemist would come up with such an incorrect model? There were many, fairly complex reasons for Pauling’s blunder, but largely it was hubris. Pauling fell victim to his own earlier success — a victory against a rival group of researchers — which made him feel infallible. In the words of Nobel Laureate Maurice Wilkins: “Pauling just didn’t try. He can’t really have spent five minutes on the problem himself.”
Finally, from the evolution of life we come to the evolution of the universe as a whole. Einstein’s blunder reminds us all that human logic is not mistake proof, even when exercised by a monumental genius. What was Einstein’s blunder? In 1917 Einstein first attempted to understand the entire cosmos in light of his theory of General Relativity. At the time, Einstein was convinced that the universe was unchanging and static on its largest scales. However, since he knew that every mass in the universe gravitationally attracts every other mass, he concluded that he needed to add something to prevent the universe from collapsing under its own weight. To achieve a static configuration, Einstein introduced a “fudge factor” into his equations, creating a repulsive force that precisely balanced gravity. This term became known as the “cosmological constant.” In the late 1920s, however, cosmologist Georges Lemaître and astronomer Edwin Hubble discovered that our universe is in fact expanding. Einstein realized that in an expanding universe gravity would simply slow the expansion down, just as the Earth’s gravity slows down the motion of a ball thrown upward, and no precise balance was needed. He therefore removed the cosmological constant from his equations, even though the theory definitely allowed for its inclusion, and for the rest of his life regretted having introduced it in the first place. Things took an unexpected turn in 1998, when two groups of astronomers discovered that not only is the cosmic expansion not slowing down, it is in fact speeding up. Moreover, the acceleration appears to be driven precisely by Einstein’s cosmological constant! So Einstein’s blunder was not the introduction of this term, rather it was its removal. For some geniuses, what initially appears to be a mistake can turn out to be great insight.
Despite their blunders, and perhaps even because of them, the individuals I have sketched here (and others, all of whom I describe more fully in Brilliant Blunders), have catalyzed great innovations. The impact of their ideas has been felt across all aspects of the evolution of life on Earth, of the Earth itself, of stars, and of the universe as a whole. But the blunders and the reactions of these geniuses to them have also demonstrated something that modern neuroscientists have concluded: that humans are not purely rational beings capable of completely turning off their emotions. Rather, our brains integrate emotions into the stream of rational thought.