### What Is Pi General forum

8 replies. Last post: 2020-12-19

What Is Pi
• The_Burglar at 2020-12-15

another christmas cracker

Definitions that give the value of PI

• metzgerism at 2020-12-15

pie is always valuable

One fun way to express Pi is in terms of the success probability of certain geometric experiments.  The classic one is tossing a needle onto the floor “at random” and asking, what’s the probability it crosses between two floorboards?

https://en.wikipedia.org/wiki/Buffon%27s_needle_problem

• Oakmoss at 2020-12-16

People love asking “What is Pi?”, but has anyone ever asked "How is Pi?"

• Carroll ★ at 2020-12-16

Pi is half of the whole it should be.

The strangest way I know to get decimals of Pi, through counting collisions of blocks: https://www.youtube.com/watch?v=jsYwFizhncE 3Blue1Brown video.

Another strange fact that maybe aliens would not discover is the BBP formula allowing to compute the hexadecimal digits of Pi, one by one:  https://en.wikipedia.org/wiki/Bailey%E2%80%93Borwein%E2%80%93Plouffe_formula

• Ray Garrison ★ at 2020-12-16

to calculate the area of a pie, remember pie are square

• David J Bush ★ at 2020-12-18

Carroll, so for n digits of accuracy using a base B numbering system, the ratio of masses must be B^n and the total number of adiabatic collisions is always floor(pi*(B^n)). Of course B is usually 10.

• Carroll ★ at 2020-12-19

@David there is a sqrt in the mass ratio: sqrt(m2/m1) so if m2 is B^n and m1 is 1 we get B^(n/2) hence floor(pi*(B^(n/2)).