6 Times Einstein Missed the Mark, but Still Changed Physics

Albert Einstein is undeniably one of the greatest names in physics. But Einstein, for all his contributions to the physics of spacetime, was a human being confined to his own time in history. While that makes his predictions all the more impressive, it also means that, at other times, Einstein was either slightly off the mark or—dare I say it—wrong.

That said, I’d be remiss not to provide more context, lest I subscribe to certain, popular accounts of how Einstein hated such-and-such in physics. He didn’t, really, and I don’t intend to argue anything of the sort. In fact, a closer look at Einstein’s “errors†reveals the physicist’s perceptive yet prudent way of thinking about our universe.

1. Gravitational waves are too weak to be detected

When Einstein published his monumental papers on the general theory of relativity in 1916, he predicted that powerful ripples in spacetime would manifest as wave-like energy forms that propagate across the universe. In 2015, the LIGO Collaboration confirmed that gravitational waves were real; Einstein was right.

By 1936, many had accepted Einstein’s predictions—except for, apparently, the man himself. After reviewing his calculations, Einstein, with collaborator Nathan Rosen, concluded that the math was incomplete. In a letter to fellow physicist Max Born, he wrote, “I arrived at the interesting result that gravitational waves do not exist, though they had been assumed a certainty to the first approximation.â€

After a famous scuffle with the journal Physical Review, as well as other physicists pointing out errors in his 1936 paper, Einstein again revised his views and took a more measured, tentative approach. Gravitational waves may exist, but they should be too weak to detect. He was wrong.

2. Quantum entanglement cannot be real

Einstein’s supposed disdain for quantum mechanics overshadows his essential contributions to modern quantum mechanics. To be clear, Einstein accepted quantum mechanical phenomena but was convinced that the theory describing them was incomplete.

One example is quantum entanglement, an odd state in which two separated particles are linked such that measuring the state of one allows the prediction of the other’s state. Einstein’s qualms were that “elements of the physical reality†must be confirmed by “experiments and measurements†that can be translated into physical theory.

Unless these particles were communicating faster than the speed of light, we must be missing some hidden, more realistic variable connecting the two. These arguments were introduced in a famous 1935 paper co-written by Einstein, Rosen, and Boris Podolsky, and came to be known as the EPR Paradox.

This paradox was later shown to be incompatible by both theoretical and experimental work, but some parts of Einstein’s questions remain unanswered: Can we devise a flawless physical theory of entanglement?

3. Gravity and electromagnetism can be unified without quantum mechanics

Einstein spent the last 30 years of his life attempting to formulate a single theory to unify all the forces of nature. Specifically, he sought to combine gravity and electromagnetism—and without depending on quantum mechanics, whose arbitrariness he believed could be dispelled by his unified theory.

“I must seem like an ostrich who forever buries its head in the relativistic sand in order not to face the evil quanta,†he joked in a 1954 letter.

“Physicists work with deep-seated intuitions about the way the world is put together,†John D. Norton, a historian and philosopher of science at the University of Pittsburgh, told Gizmodo. Such intuitions “quietly but powerfully control the direction of their research,†he said. “For Einstein, it was that all the forces of nature could be combined into a single, overarching unified field.â€

His attempts never came to fruition, although Einstein’s pursuit of a unified theory “established unification as an important goal of physics… commonly called the ‘holy grail’ of modern physics,†according to the American Physical Society.

4. The universe is static and unchanging

For decades, the cosmological consensus has been that the universe expanded—and continues to do so—at an exponential rate.

But this idea rose to prominence after Einstein’s time. Einstein believed in a static universe, introducing a “mathematical fudge factor†into his equations, known as the cosmological constant. This constant suggested there was some repulsive force counteracting gravitational attraction in the universe, balancing things out so that the universe would remain static.

What unfolded next was nothing short of ironic. Einstein later discarded the cosmological constant, referring to it as an arbitrary element he’d tacked onto his equations. Then in the 1990s, researchers revived the abandoned theory, giving it new life as dark energy.

5. Black hole singularities cannot exist in nature

Was Einstein opposed to the notion of black holes? There is, surprisingly, a simple answer to this question, according to Norton: “Yes. He was against them.â€

By now, you may have noticed a trend: Einstein predicts a physics breakthrough, then later disowns his brainchildren. Similarly, general relativity hinted at the inevitability of black holes—until, in 1939, Einstein strongly rejected their feasibility, at least within proper physics.

Einstein had a very mathematical view of spacetime. A black hole so dense that all matter—including light—collapses at what’s now called the event horizon was “an unimaginable misfortune [malheur] for theory,†as Einstein noted during an academic meeting in 1922.

“Einstein preferred certain coordinate-based descriptions of his spacetimes,†Norton said. “These representations displayed such infinite divergences at the event horizon. They are mathematical expressions employing variables and functions of them.â€

Singularities, on the other hand, led to the collapse of these nicely defined mathematical structures for Einstein. In a 1935 paper with Rosen, he noted that a singularity “brings so much arbitrariness into the theory that it actually nullifies its laws.â€

Then again, Einstein’s predictions came long before empirical observations that have enabled physicists to create a workable, geometric description of black holes. Would Einstein have accepted the findings of LIGO or the Event Horizon Telescope?

“I would like to imagine he would be convinced,†Norton mused. “One thing I learned from studying Einstein’s work is that his next step is rarely the one that I imagined to be the natural one. Predicting what Einstein would do is vastly harder. He was Einstein!â€

6. “God does not play dice.â€

On the topic of Einstein’s tendencies, he clearly disliked arbitrariness in physical models. That was the driving force behind his skepticism of quantum mechanics and singularities, and it was why he tried so fervently to devise a grand, unified theory of physics.

A precursor to these ambitions may have been general relativity, an overarching theory unifying gravity and inertia. And he was clearly successful, as general relativity “has survived all challenges for over a century and is the foundation of all modern work in gravity and cosmology,†Norton said.

Again, Einstein did not reject indeterminism itself—rather, he believed there was a deeper level of reality that humanity hadn’t yet arrived at, a clearer theory that could sufficiently capture the fundamental nature of the universe.

It’s easy for us to now nitpick at Einstein’s older ideas, but really, he “had his own methods and approaches and employed them consistently and effectively,†Norton said. “Something worked.â€

Indeed, if this list is any guide, Einstein’s pushback against popular perspectives—including ones he introduced—produced some of the richest, most thought-provoking debates in the field, many of which continue to this day.

As Norton says, it’s difficult to predict how Einstein would react to how his ideas were proven or disproven with the advance of physics. But I’d imagine that he’d have a lot of questions, with a fair number of controversial takes!