# Kiyoshi Ito, inventor of stochastic calculus, dead at 93

**URL:** <https://boards.straightdope.com/t/kiyoshi-ito-inventor-of-stochastic-calculus-dead-at-93/474523>\
**Category:** Miscellaneous and Personal Stuff I Must Share\
**Created:** [November 26, 2008, 3:31am UTC](https://boards.straightdope.com/t/kiyoshi-ito-inventor-of-stochastic-calculus-dead-at-93/474523 "2008-11-26T03:31:49Z")\
**Posts on this page:** 3\
**Page:** 1

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**Author:** ![ultrafilter](https://avatars.discourse-cdn.com/v4/letter/u/3d9bf3/32.png) [@ultrafilter](https://boards.straightdope.com/u/ultrafilter)\
**Post date:** [November 26, 2008, 3:31am UTC](https://boards.straightdope.com/t/kiyoshi-ito-inventor-of-stochastic-calculus-dead-at-93/474523/1 "2008-11-26T03:31:49Z")

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From the [NY Times](http://www.nytimes.com/2008/11/24/business/24ito.html?_r=1&ref=obituaries):

> [@](#):
>
> Kiyoshi Ito, a mathematician whose innovative models of random motion are used today in fields as diverse as finance and biology, died Nov. 10 at a hospital in Kyoto, Japan. He was 93.
> 
> …
> 
> Mr. Ito is known for his contributions to probability theory, the study of randomness. His work, starting in the 1940s, built on the earlier breakthroughs of Albert Einstein and Norbert Wiener. Mr. Ito’s mathematical framework for describing the evolution of random phenomena came to be known as the Ito Calculus.

This is probably of somewhat specialized interest, but it seems worth passing along. Roughly speaking, stochastic calculus is the extension of the methods of ordinary calculus from normal variables to random processes. It’s foundational to modern financial theory, widely used in cellular biology and particle physics, and probably has applications that I’m not aware of.

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**Author:** ![Autolycus](https://avatars.discourse-cdn.com/v4/letter/a/22d042/32.png) [@Autolycus](https://boards.straightdope.com/u/Autolycus)\
**Post date:** [November 26, 2008, 8:27am UTC](https://boards.straightdope.com/t/kiyoshi-ito-inventor-of-stochastic-calculus-dead-at-93/474523/2 "2008-11-26T08:27:19Z")

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I don’t know a lick about it, but surely he was a giant among men. Namu Amida Butsu (very roughly translates to ‘rest in peace.’)

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**Author:** ![Darryl\_Lict](https://avatars.discourse-cdn.com/v4/letter/d/7cd45c/32.png) [@Darryl\_Lict](https://boards.straightdope.com/u/Darryl_Lict)\
**Post date:** [November 26, 2008, 9:13am UTC](https://boards.straightdope.com/t/kiyoshi-ito-inventor-of-stochastic-calculus-dead-at-93/474523/3 "2008-11-26T09:13:25Z")

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So that was the mother fucker who damned near terminated my grad school career. Fucking A, I got a B- in an undergraduate statistical signal processing class and was about 0.07 points above academic probation. To this day, I’m still not sure what a stochastic process is.