The Most Controversial Problem in Philosophy

do not hit the like button or the dislike button at least not yet I want you to consider a problem that's been one of the most controversial in math and philosophy over the past 20 years there is no consensus answer so I want you to listen to the problem and then vote for the answer you prefer using the like and dislike buttons okay here is the setup Sleeping Beauty volunteers to be the subject of an experiment and before it starts she's informed of the procedure on Sunday night she will be put to sleep and then a Fair coin will be flipped if that coin comes up heads she'll be awakened on Monday and then put back to sleep if the coin comes up Tails she will also be awakened on Monday and put back to sleep but then she will be awakened on Tuesday as well and then put back to sleep now each time she gets put back to sleep she will forget that she was ever awakened in the brief period anytime she's awake she will be told no information but she'll be asked one question what do you believe is the probability that the coin came up heads so how should she answer feel free to pause the video and answer the question for yourself right now this was my reaction after hearing the problem for the first time I mean the intuitive answer that pops into my head is clearly one in three it could be the Monday when it came up heads or it could be the Monday when it came up Tails or it could be the Tuesday when it came up Tails but you know what's really interesting is you just answered that the probability of a coin coming up heads is one-third I think a lot of this comes down to what specific question is asked of her what is the probability that a Fair coin flipped gives heads that's 50 what is the probability that the coin came up heads I would say the answer is a third from her perspective yeah I it's it's remarkably the same question the simple reason why Sleeping Beauty should say the probability of heads is one half is because she knows the coin is fair nothing changes between when the coin is flipped and when she wakes up and ...