With the announcement Thursday that scientists had discovered direct evidence of gravitational waves, one of Albert Einstein’s wildest theories was validated. It was further proof (as if any were needed) of Einstein’s genius.
But being a genius did not prevent the scientist, who died in 1955, from making mistakes. Some of his most significant errors occurred when he refused to believe the implications of his own ideas.
Lawrence M. Krauss, a theoretical physicist at Arizona State University, walked us through four of Einstein’s notable blunders.
1. Quantum Entanglement
Einstein referred to this physical phenomenon, which suggests that objects separated by great distances can affect one another, as “spooky action at a distance.” He rejected the possibility, refusing to believe that objects could influence each other no matter how far apart they were.
“He didn’t think the spooky action at a distance would be verified, but it was,” Dr. Krauss said. “He thought that was somehow unphysical. He presented this as an example of why quantum mechanics is probably wrong, but in fact it’s right.”
A study released by a group of scientists in October provided the strongest evidence yet to support the claim. It followed a string of other experiments that have been conducted since the 1970s that suggest Einstein was too dismissive.
“These tests have been done since the late ’70s but always in the way that additional assumptions were needed,” one of the scientists involved told The Times in October. “Now we have confirmed that there is spooky action at distance.”
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Einstein at home in Princeton, N.J., in 1944.CreditPopperfoto/Getty Images
2. Gravitational Lensing
In 1936, Einstein published an article in Science magazine, detailing what he called “lens-like action of a star by the deviation of light in the gravitational field,” or, in less scientific terms, the idea that objects in space could divert light.
“Of course,” he wrote offhandedly, “there is no hope of observing this phenomenon directly.”
But Dr. Krauss said: “He only thought of lensing by stars and didn’t think of galaxies. He really wasn’t much of an astronomer.”
Gravitational lensing has become one of the most useful techniques available to scientists in mapping the universe.
3. The Cosmological Constant
In trying to apply his general theory of relativity to the structure of the universe, Einstein threw into his equation a term representing a “cosmological constant,” because he believed he needed to represent a repulsive force that would counter the attractive force of gravity in order to represent the universe as static.
Years later, when it was discovered that the universe was expanding, Einstein discarded the term. He was said to have called it “his biggest blunder.” (Though in recent years, questions have been raised about whether that quote was misreported.)
In any case, Dr. Krauss said that Einstein should not be criticized for attempting to balance the equation, since the idea that the universe was static was accepted at the time. But, he said, that does not let Einstein off the hook.
“The second aspect is, it was also a mathematical blunder because the cosmological constant doesn’t produce a static universe,” he said. “It makes the universe expand faster and faster, which is what we’re experiencing right now.”
“Had he had the courage of his convictions, in some sense, he would have realized that his theory required a universe to be expanding, not one that was static, and he could have predicted it,” he added. “And as I often say, if he just could have predicted it, he would have been famous.”
(The cosmological constant, as it turns out, may not have been so wrongheaded. NASA scientists say that the term “significantly improves the agreement between theory and observation.” Dr. Krauss says that it is possible that dark energy may act in exactly the way that the term was originally meant to represent.)
Direct evidence of gravitational waves has Einstein back in the news again now, since he originally proposed their existence a century ago. So it’s funny to learn that he changed his mind, 20 years after suggesting the idea.
“He wrote a paper saying they don’t exist, and retracted the idea,” Dr. Krauss said. “It turned out he had made a mathematical error that was only discovered just before he was going publish” the retraction.
That paper was rejected by a first journal, Physical Review, Dr. Krauss said, after the mathematician and physicist reviewing the paper, Howard P. Robertson, found the error.
Einstein, angry at having his paper reviewed, planned to publish it in another, obscure journal, but found his error independently and managed to rewrite the paper so that it was accurate before it was published
“He wanted to retract the very thing we just discovered this year,” Dr. Krauss said, chuckling. “I think it’s a nice bit of poetry.”
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