4 ms·

Damn, that is cool

• somenameforme 2y ago
  Yeah this is probably the neatest little 5 second math thing I've ever seen. Can't believe I hadn't seen this before.
  • soulofmischief 2y ago
    John von Neumann strikes again! Wikipedia: https://en.wikipedia.org/wiki/Fair_coin#Fair_results_from_a_biased_coin https://en.wikipedia.org/wiki/Fair_coin#Fair_results_from_a_... Original paper: https://mcnp.lanl.gov/pdf_files/InBook_Computing_1961_Neumann_JohnVonNeumannCollectedWorks_VariousTechniquesUsedinConnectionwithRandomDigits.pdf https://mcnp.lanl.gov/pdf_files/InBook_Computing_1961_Neuman...
• amelius 2y ago
  It's a nice trick, but it requires a lot of extra coin flips. Imagine you have a coin with p(1)=0.501, and you want 1000 random bits. With the proposed method, this will take about 4000 coin flips. Surely, since the coin is quite close to being fair, it should be possible to do it with far fewer flips ...