video thumbnail 17:22
How to predict random numbers

2021-11-26

[public] 132K views, 6.42K likes, dislikes audio only

channel thumbAlphaPhoenix

So it's been almost 2 years since I said the random-number-machine follow-up video was coming "soon", and it's finally time! (Combined with a fun bit of math regarding perfect shuffles in reply to a fascinating Matt Parker video)

If you take a histogram of the wait times between geiger tube ticks, you get a beautiful exponential decay curve - most gaps between ticks are extremely fast, and it's rare to go a long time without a tick. You can use this property of random numbers to show that ticks coming from a tube are indeed randomly distributed.

Conveniently, runs of interleaved cards in shuffled decks of cards ALSO follow this exponential decay distribution, with short runs representing short wait times between ticks and very long runs of perfectly interleaved cards being rare, just like long wait times between geiger tube ticks. Because these properties of random numbers are so predictable, you can actually calculate the probability of executing a "perfect" or "Farro" shuffle by accident.

Music Credits, etc.:

I Dunno by grapes is licensed under a Creative Commons Attribution license (https://creativecommons.org/licenses/by/3.0/)

http://ccmixter.org/files/grapes/16626

Arcadia - Wonders by Kevin MacLeod is licensed under a Creative Commons Attribution license (https://creativecommons.org/licenses/by/4.0/)

Source: http://incompetech.com/music/royalty-free/index.html?isrc=USUAN1100326

Artist: http://incompetech.com/


Intro
/youtube/video/QzI6GFzH7ZA?t=0
Random number prediction
/youtube/video/QzI6GFzH7ZA?t=259
Results
/youtube/video/QzI6GFzH7ZA?t=711
AlphaPhoenix I'm Brian Haidet - PhD in Materials Science, but I'd also describe myself as artist, maker, and Hawaiian shirt enthusiast. On this channel, You'll find my side projects and favorite physics demos - I hope you enjoy!
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