Albert Einstein’s theories and formulae have rarely been challenged. His theorems have been the basis of further scientific research discovery even in the 21^{st} century. Hence it comes as a shock when two never-before-seen letters confirm the unthinkable; Einstein had once committed a mathematical error in one of his many published papers.

If that’s not surprising enough, the extremely rare letters, confirm that the error was pointed out by a 23-year-old student. But the humble genius that he is, Albert Einstein, though initially dismissed the claim politely, in one of the follow-up letters, not only admitted the error, but applauded the man for his diligence and mathematical prowess.

23 year old Herbert Salzer was studying for a Master’s degree in physics, when he wrote to Albert Einstein to point out that an equation in one of his published papers was actually wrong. Herbert supported his argument with an equation that he himself had written. Though it was rare for a student to challenge such a prodigy, it was even rarer for a noted persona to reply, let alone closely examine the claim and counter-verify his own work.

The correspondence related to Albert Einstein’s work on a unified theory of Distant Parallelism – A Study Of Gravitation and Electromagnetic Fields. Einstein had invested more than three years pursuing the theory and possible linkages between gravitation fields and electromagnetic fields, but chose to simply abandon his hard-work when he failed to find strong evidence to support his notions.

Interestingly, the German physicist initially, politely dismissed the claim, reported *ABLX Boston*. Einstein replied back to Herbert with the complex algorithm re-written, that was aimed at defending his work. He even chose to conclude the letter with the following words:

“I will now show that equation is really, really not the equation you specified’ before signing off ‘Yours respectfully, A. Einstein”

All could have ended there, but the untiring dedication that Einstein had, nagged him to recheck his equations. This resulted in a completely unexpected hand-written letter delivered to Herbert. Written on September 13, 1938, the letter reads,

“Shortly after I wrote you, I noticed that the error was on my side…”

Einstein continued to closely examine what Herbert put forth with equations that were now revised. After the noted physicist agreed with Herbert, Einstein concluded,

“…The transformation required is exactly that of a tensor in the Theory of Relativity. Therefore, your transformation equation is correct, mine wrong. I don’t have my earlier work available. But it sure seems that I have made the same mistake there. This will make my assertions about the shape of the first approximation inaccurate.”

Needless to say, Herbert went on to become an acclaimed physicist and published more than 100 papers.

[Image Credit |ProfilesInHistory/BNPS via Daily Mail, Fun Chap]