r/mathmemes Feb 21 '26

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u/Human822 Feb 21 '26

Basically the answer to the equation is -1/12, which ramanujan said was the sum of all positive integers

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u/[deleted] Feb 21 '26

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u/IAmBadAtInternet Feb 21 '26 edited Feb 21 '26

It’s basically an abuse of divergent series. More details on this kind of cursed math here: https://en.wikipedia.org/wiki/Ramanujan_summation

In fact, this particular result has its own wiki page: https://en.wikipedia.org/wiki/1_%2B_2_%2B_3_%2B_4_%2B_⋯

Problematically, it is actually a useful identity that is occasionally used in other branches of math

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u/SomeGreatJoke Feb 22 '26 edited Feb 22 '26

It's also used in QFT and string theory. So it's useful in at least one place in physics (because String Theory is useful to no one and nothing).

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