Explainer

Hey, It’s Only a Theory …

How often was Albert Einstein wrong?

Albert Einstein.
Albert Einstein in 1938

Photograph by AFP/Getty Images.

Physicists at the CERN laboratory in Geneva announced in September that they had detected a neutrino traveling faster than the speed of light, a finding that violated Einstein’s venerable theory of special relativity. The journal Science reported Wednesday that a faulty connection between a GPS and a computer likely caused the anomaly, leaving Einstein’s theory intact. How many times has Einstein been proven wrong?

At least twice on major issues. While Einstein accepted large portions of the theory of quantum mechanics, he rejected certain of its fundamental tenets that have since been born out in experiments. In layman’s terms, quantum mechanics posits that certain physical realities are unknowable—not because of our limited powers of observation and calculation, but because reality itself contains an element of uncertainty and probability. Like Newton before him, Einstein believed in equations and predictability, and he chafed at the conclusion that reality could be partially random. This disagreement is the basis for his famous statement that God “does not play dice.” While quantum mechanics is enormously complicated, even for the physicists who study it, most modern-day scientists think Einstein’s objections were likely misguided.

Einstein had a more specific objection to quantum mechanics. According to the theory, particles can become paired such that an impact on one of them can instantaneously affect the other, no matter how far apart the particles are. Einstein argued that this was impossible, because information could not travel between the two particles faster than the speed of light. (He dismissed this aspect of quantum mechanics as “spooky action at a distance.”) In other words, he thought it violated the special theory of relativity, just like those neutrinos were supposed to have done at CERN in September. In this case, experiments have proven Einstein wrong—distant particles do seem capable of reacting to each other simultaneously. However, most physicists say the phenomenon doesn’t really violate Einstein’s special theory of relativity (PDF). They claim that, in certain cases, space isn’t enough to break an intrinsic connection between particles. (If you find this impossible to understand, take the advice of physicist Richard Feynman, who famously counseled his listeners, “Do not keep saying to yourself, if you can possibly avoid it, ‘But how can it be like that?’ because you will get ‘down the drain’, into a blind alley from which nobody has yet escaped. Nobody knows how it can be like that.”)

While Einstein continued these disputes with quantum theorists until his death, he owned up to another major blunder. Early in the 20th century, Einstein realized that his theory of gravity indicated the universe must be either expanding or contracting. At the time, physicists thought the universe was static, so Einstein added a term known as the “cosmological constant” to his equations to accommodate the conventional wisdom. In the late 1920s, however, Edwin Hubble proved that the universe is, in fact, expanding. Einstein withdrew his constant with no small amount of embarrassment.

There’s a coda to this story. In 1998, astrophysicist Saul Perlmutter and others discovered that the universe is not only expanding, but expanding at an accelerating rate. (The work won them the Nobel Prize for Physics in 2011.) The finding once again caused problems for Einstein’s calculations, and some physicists think that the best way to remedy them is to add a constant back into the equations. So Einstein may have been correct, although for the wrong reasons.

Despite these errors and some smaller ones here and there—Einstein’s doctoral thesis contained a mathematical mistake that took him years to correct—physicists who challenge Einstein usually lose. Editors at physics journals receive submissions every year claiming to disprove the special theory of relativity, and they always turn out to be wrong. Instrumental failures, like those experienced at CERN, are a relatively common failing among Einstein’s antagonists.

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Explainer thanks Peter Galison of Harvard University and author of Einstein’s Clocks, Poincare’s Maps: Empires of Time; John Rigden and Clifford Will of Washington University of St. Louis; and John Stachel of Boston University.

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