Albert Einstein was one of the world's most important leading scientists of all time. His work laid the foundations for some of the most important human discoveries of all time.
Yet even a man of his talents was not immune from making errors, from time to time.
After all, as the famous saying goes, "to err is human".
Whilst we have only included six here (well five significant ones), he does appear to have made many more in his long and intellectually productive life.
1. Einstein called this his greatest mistake
Einstein was a very accomplished scientist, but being human, he got things wrong, now and again. His biggest one, according to himself, was to do with the cosmological constant.
He felt the need to add it to his general theory of relativity.
Einstein believed that it was needed to address an issue that he believed the Universe was static and unchanging. His equations, on the other hand, seemed to show the complete opposite was true in reality.
His biggest surprise was to find that, according to his own work, the Universe appeared to be expanding. Not only that, but this expansion seemed to be accelerating.
Whilst unknown to him at the time, modern scientists think he might have been on to something. What he called the cosmological constant, - Λ, might actually be dark energy.
This is a theoretical force that appears to be the cause for the expansion. But not all modern scientists agree.
2. He made some mistakes in his proof for E = mc^2
In 1905, Einstein published various papers about the photoelectric effect, Brownian motion and special relativity, and mass-energy equivalence. For this reason, 1905, is called his "miracle year."
Yet no one, at that time, had worked out the idea of "rest energy" for massive objects. Some had proposed E = Nmc^2, where N was a number like 4/3, 1, 3/8, but nobody could show which one was true.
That was until Einstein in his "miracle year".
Whilst this makes for a nice story, the truth is less glamorous. Einstein's derivation for his famous E = mc^2 only worked for a particle at rest.
Whilst he did later publish his work on special relativity (where the laws of physics are dependant on an observer's frame of reference), his early work could not account for a particle in motion.
He would later try to rectify this issue, no less than seven times throughout his lifetime, each one was later proved to be flawed.
It wasn't until Max von Laue made the critical advance, six years later, that showed the flaw in Einstein's work: one must get rid of the idea of kinetic energy.
Today we now talk about total relativistic energy instead. This is where the traditional kinetic energy -- KE = ½mv^2 -- can only emerge in the non-relativistic limit.
Just so you know.
3. Einstein helped develop, but hated, quantum mechanics
Einstein's groundbreaking work led to the eventual development of an entirely new field of study - quantum mechanics. His 1905 paper on the photoelectric effect, for which he won a Nobel Prize, was instrumental in the field's birth.
But despite this fact, Einstein grew to famously despise this new upstart. For him, it appeared mysterious, purely theoretical and downright hard to actually prove in reality.
He was especially at odds with quantum mechanics apparent ultimate conclusion that the Universe was uncertain and chaotic. Einstein was also famously opposed to the ideas behind the famous Schrodinger's Cat paradox.
Oh well, not everyone is perfect.
4. Einstein was too stubborn to give up on Unified Field Theory
For almost 30 years of his life, Einstein would stick doggedly to the idea of uniting gravity and electromagnetism. His work was to build on his earlier work on Special Relativity as well as the Newtonian gravitational description of the movement of heavenly bodies.
Einstein, like many before him, dreamt of a day when the laws of physics could be unified under one "Grand Theory." At its core, the mission sounds plausible.
After all, there must be a way of explaining all of nature from a few simple, fundamental rules and parameters.
Other theories had been successfully united before, such as Coulomb's law, Gauss' law, Faraday's law, and permanent magnets could all be explained in a single framework: Maxwell's electromagnetism. Surely this must also be possible with the fundamental laws of the Universe?
As new evidence emerged for the existence of weak and strong nuclear forces - which appeared to obey the laws of electromagnetism, Einstein dug his heels in. He completely ignored them and never attempted to include nuclear forces into his work.
Today, advancements made in our understanding of nuclear forces has ultimately led to the development of the Standard Model.
"Today, the electroweak force picture has been confirmed, with Grand Unification Theories (GUTs) theoretically adding the strong force to the works, and string theory finally, at the highest energy scales, as the leading candidate for bringing gravity into the fold." - explains Ethan Siegel in Forbes.
5. Einstein got cold feet about gravitational waves
It seems Einstein had a penchant for predicting things and then later hating them. Another example was his prediction for the existence of gravitational waves.
Gravitational waves, if you are not aware, are vibrations or ripples, in spacetime that are generated by events in space like the movement of neutron stars or the machinations of black holes. Other incredible powerful events like Supernovae or colliding black holes would result in very strong waves.
Einstein, for his part, was not opposed to the idea, but rather suspected that they would be incredibly hard to ever measure. He even came to the conclusion that black holes might not be the cause for them if they existed.
Einstein even famously attempted to publish a paper in 1936 to disprove the very notion that gravitational waves existed. This paper was later rejected.
As we know today, gravitational waves are in fact real things. Scientists have even been able to detect them - a feat for which the team was awarded the highly coveted Nobel Prize in 2015.