Why is pi here? And why is it squared? A geometric answer to the Basel problem

하늘 No.1349 [영상] 13,272
Why is pi here? And why is it squared? A geometric answer to the Basel problem
3Blue1Brown

자막 켜고 보세요

A most beautiful proof of the Basel problem, using light.
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Special thanks to these supporters: http://3b1b.co/basel-thanks
This video was sponsored by Brilliant: https://brilliant.org/3b1b

Brilliant's principles list that I referenced:
https://brilliant.org/principles/

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The content here was based on a paper by Johan Wästlund
http://www.math.chalmers.se/~wastlund...

Check out Mathologer's video on the many cousins of the Pythagorean theorem:
https://youtu.be/p-0SOWbzUYI

On the topic of Mathologer, he also has a nice video about the Basel problem:
https://youtu.be/yPl64xi_ZZA

A simple Geogebra to play around with the Inverse Pythagorean Theorem argument shown here.
https://ggbm.at/yPExUf7b

Some of you may be concerned about the final step here where we said the circle approaches a line.  What about all the lighthouses on the far end?  Well, a more careful calculation will show that the contributions from those lights become more negligible.  In fact, the contributions from almost all lights become negligible.  For the ambitious among you, see this paper for full details.

If you want to contribute translated subtitles or to help review those that have already been made by others and need approval, you can click the gear icon in the video and go to subtitles/cc, then "add subtitles/cc".  I really appreciate those who do this, as it helps make the lessons accessible to more people.

https://youtu.be/d-o3eB9sfls

https://heisme.skymoon.info/a/SuggInfo/1349  

그대는 푸르른 하늘과 휘영청 달빛을 바라보며 세상 모든 것을 밤낮으로 곱씹어 봅니다. 하지만 그것들은 봄날 꿈속에서 다시 꾼 꿈처럼 아른거리기만 합니다 [하늘-바람 거친 이 세상에서]