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Adam Elga: 2 ideas and puzzles worth knowing

2 ideas and puzzles from Adam Elga, each explained in a minute and credited to the original work. Free on Savvy.

• A coin flip she can't remember produces two competing 'correct' probabilities

  Sleeping Beauty is put to sleep; a coin flip decides whether she's woken once, or woken twice with her memory erased between wakings. Each time she wakes, what should she believe t…

  — Adam Elga, Self-locating belief and the Sleeping Beauty problem

• You wake up with no idea if it's day one or two — what are the odds?

  Sleeping Beauty agrees to an experiment: she's put to sleep, and a fair coin is flipped. On heads, she's woken once, on Monday. On tails, she's woken twice, once on Monday and once…

  — Adam Elga, Self-locating belief and the Sleeping Beauty problem

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