Even if you’ve never cracked open a physics textbook, there’s a good chance you’ve still heard of Albert Einstein. With a name that is now synonymous with genius, Einstein broke into the physics scene at the turn of the 20th century with ideas about our universe that are still fundamental to science today, including the famous notion that energy is proportional to an object’s mass multiplied by the speed of light. Or, E = mc^2.
In the century-plus since Einstein published his seminal paper on general relativity (which gave us ideas like time dilation and space-time), modern scientists have continued to prove many other of Einstein’s predictions correct. However, even for a great physicist like Einstein, not all his ideas could be bangers.
5. Einstein didn’t believe in black holes
Today, the study and even imaging of black holes is standard practice. Einstein, however, wasn’t convinced that black holes actually existed, despite the fact that they’re directly descended from his general theory of relativity.
In 1939, Einstein penned a paper for the Annals of Mathematics to refute what was called at the time a “Schwarzschild singularity,” named after astronomer Karl Schwarzschild. One of the major breakthroughs of Einstein’s theory of general relativity was the sewing together of space and time into a neat fabric, through which gravity ripples. However, in 1916, Schwarzchild realized that the same theories which established space-time could also catastrophically break down at the point of a gravitational singularity, creating a “hole” that even light couldn’t escape from.
The idea was largely disregarded until 1935, when astrophysicist Subrahmanyan Chandrasekhar predicted a mechanism in the form of an extremely dense, dying star that collapses in on itself. Today, this is the classic definition of a black hole.
Possibly to uphold his own theories about space-time, Einstein wrote in his 1939 paper that Schwarzschild singularities “do not exist in physical reality.”
4. Quantum mechanics made him squirm
Part of what made Einstein famous is his reimagining of so-called “classical mechanics” from the days of Newton.
According to Einstein, macroscopic phenomena like gravity are predictable through careful calculations. In Einstein’s perfect world, this formulaic understanding of our world would expand from the very largest stars in our galaxy to the smallest particles. Quantum mechanics, which began to emerge in the 1920s to describe the microscopic world, was on the side of chaos.
According to supporters of quantum theories, the world of atoms was actually based much more on probability than absolute certainties. In quantum mechanics, particles don’t “exist” in any given location until you observe them, and they can communicate physical changes across great distances without ever touching.
Quantum physics playing fast and loose with the order of the universe is something that Einstein objected to on a fundamental level. Famously, he told physicist Max Born that “God does not play dice with the universe,” referring to the underlying probabilistic nature of quantum mechanics.
While Einstein’s theories of relativity work well for the macroscopic world, they fail to accurately describe the world of the submicroscopic as well as quantum mechanics can.
3. He wavered on gravitational waves
In 2015, scientists confirmed one of Einstein’s theories in a massive way using extremely sensitive detectors called LIGO (Laser Interferometer Gravitational-Wave Observatory) to detect the small ripples in space-time caused by gravity. These gravitational waves were originally predicted by Einstein in 1916 as a natural side effect of general relativity. But 20 years after his initial prediction, Einstein was having serious doubts about the existence of gravitational waves on the basis that, like black holes, he believed gravitational waves would create a singularity.
“I arrived at the interesting result that gravitational waves do not exist, though they had been assumed a certainty to the first approximation,” Einstein wrote to a friend in 1936.
Perhaps lucky for Einstein in retrospect, the original paper he submitted to refute the existence of gravitational waves was sent back for revisions and corrections for mathematical errors. An angry Einstein withdrew the paper before reworking the math — and finding that gravitational waves prevailed, putting him back on the right side of history with his opinion on gravitational waves.
2. He couldn’t quite accept an expanding universe
It’s common knowledge now that our universe is not only expanding but accelerating, likely thanks to dark energy. Scientists have determined this by looking at the redshift of galaxies that indicate they’re moving away from our vantage point on Earth. However, in Einstein’s time, this finding hadn’t yet been discovered.
The assumption of early 20th century scientists, including Einstein, was that the universe was static. Based on what they were able to observe at the time, this assumption makes sense. After all, the same constellations move across the sky with Earth’s seasons. However, Einstein’s theories of general relativity ran into problems when trying to capture this alleged reality. To bridge this gap, Einstein introduced something in 1917 called the “cosmological constant” to his equations. Essentially, this unchanging factor helped keep the universe stable in Einstein’s math without impacting other elements of the equation.
This addition, however, would go on to be what Einstein allegedly called one of his biggest blunders. In 1929, a team of scientists that included Edwin Hubble made the first observation of an expanding universe from a telescope in California.
“Then away with the cosmological constant!" Einstein purportedly told Hubble some years later.
1. The “holy grail of physics” eluded him
Toward the end of his life, Einstein focused much of his energy on solving a problem that scientists today still haven’t resolved: the unification of forces under one, master theory. There are four fundamental forces that govern our world: gravity, electromagnetism, and the strong and weak nuclear forces. While these forces can be observed and explained discreetly, Einstein dreamed of a unified theory that could capture all these forces at once. In particular, he was interested in uncovering a theory to join the two most observable forces: gravity and electromagnetism.
While Einstein is not alone in this dream, he and even modern scientists have yet to solve this problem. The Standard Model was introduced in the 1970s to jointly explain the interactions of electromagnetism and the nuclear forces, but gravity has infamously not fit into this model.
At the moment, it looks like Einstein was wrong about being able to unify gravity with the other forces. That said, stranger things have happened than future scientists dusting off Einstein’s theories to prove them correct.
On his 143rd birthday, Inverse celebrates the world’s most iconic physicist — and interrogates the myth of his genius. Welcome to Einstein Week.