
Most interesting mathematics mistake? (2009) - panic
https://mathoverflow.net/questions/879/most-interesting-mathematics-mistake
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Mountain_Skies
There was the Reinhart-Rogoff error, which claimed economic growth declines
(0.1%) when a nation's debt passes 90% of GDP. For years this was used to set
economic policy, especially austerity measures, in western governments. When
someone (a grad student IIRC) actually bothered to check the Excel formulas,
an error was found and the actual number should have been a 2.2% increase
instead of a 0.1% decrease.

That the error occurred isn't amazing but it is mind blowing that so much
government fiscal policy was set based in part on this one spreadsheet that no
one bothered to double check. Blame extends both to those who used the model
to justify the policies and to those who opposed the policy but never checked
the assumptions it was based upon.

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OnlineGladiator
I feel like you're missing the most interesting point of this story - how many
other policies are decided based upon nonexistent or erroneous data that
nobody bothered to verify? You assume it's an anomaly, but what if this were
the norm?

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Mountain_Skies
My post was in no way meant to be exhaustive but it's good to know that since
you failed to list any of my other shortcomings in life that you believe me to
be otherwise perfect. Afterall, you failed to list all of my failures so you
must be assuming they don't exist.

~~~
OnlineGladiator
My reasoning was that if you thought it were the norm, it wouldn't be worth
mentioning. And you talk about it as a 'most interesting' example so it seems
unlikely you didn't consider it an anomaly.

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tyingq
The $125 million metric conversion mistake with the Mars lander comes to mind:
[https://www.latimes.com/archives/la-
xpm-1999-oct-01-mn-17288...](https://www.latimes.com/archives/la-
xpm-1999-oct-01-mn-17288-story.html)

~~~
CamperBob2
I see the question as pertaining to pure mathematics, rather than engineering
or applied science. For sheer mental anguish, I imagine it's hard to beat the
flaw in Andrew Wiles's first edition of his Fermat proof. Discovering _that_
must have sucked.

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enriquto
wow, the first answer is amazing! It includes an intervention by Perko
himself, pointing out further errors. What a time to be alive.

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JadeNB
"First answer" is ill defined, since answers can move around depending on view
options and later answers (and it's not chronologically first). Probably
better to link directly:
[https://mathoverflow.net/a/9059](https://mathoverflow.net/a/9059) .

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arberavdullahu
>All of the (in retrospect) misguided attempts to prove Euclid's Parallel
Postulate, which eventually lead Gauss to develop hyperbolic geometry.

I had geometry last year and we mentioned that a lot of mathematicians tried
to prove Euclid's Parallel Postulate. They tried adding a lot of properties to
geometries. Saccheri is worth mentioning for contributing a lot in this
development, especially for Saccheri quadrilateral!

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emmelaich
Maybe not of great import but I found it interesting that Ramanujan made some
mistakes. Hardy found it worth noting that he made mistakes.

Perhaps to be expected, since he had enormous intuition but was unfamiliar
with some parts of mathematics.

[https://mathoverflow.net/questions/288410/what-did-
ramanujan...](https://mathoverflow.net/questions/288410/what-did-ramanujan-
get-wrong)

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nottorp
Sad thing is the question was closed. If it’s not ready for copy paste it’s
too broad for stack overflow...

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hyperpallium
You can prove a theorem, but who shall prove the proof?

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F-0X
The proof prover proves the proof, but who shall prove the proof prover?

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enriquto
it's provers all the way down!

