A lovely puzzle (Galperin): Why do colliding blocks compute π?

[Batalov]

Formulation:


Solution:

[retina]

Nice graphics. Good speaker. Interesting problem.

Whenever I see pi involved I know there is a way to make a circle somehow in the calculations. Let me think about it.

[SmartMersenne]

Originally Posted by Batalov

Formulation:


Solution:

3rd movie in that series is also beautiful:

[ATH]

All of the videos from 3Blue1Brown has these nice graphics.

His series on linear algebra explains it so intuitively with the graphics. It should be taught this way in school:

https://www.youtube.com/watch?v=fNk_...2xVFitgF8hE_ab


He also have a series on calculus I have not watched yet:

https://www.youtube.com/watch?v=WUvT...53DwVRMYO3t5Yr

[Dr Sardonicus]

Originally Posted by retina

Whenever I see pi involved I know there is a way to make a circle somehow in the calculations. Let me think about it.

De Morgan was explaining to an actuary what was the chance that a certain proportion of some group of people would at the end of a given time be alive; and quoted the actuarial formula, involving , which, in answer to a question, he explained stood for the ratio of the circumference of a circle to its diameter. His acquaintance, who had so far listened to the explanation with interest, interrupted him and exclaimed, "My dear friend, that must be a delusion, what can a circle have to do with the number of people alive at a given time?"

-- W.W. Rouse Ball, Mathematical Recreations and Essays