I never said anything about aging. You also don’t have to assume you’ll ever die. I’m infinitely more likely to be 20 if I’ll die than if I won’t.
It wouldn’t apply if you don’t know how old you are, as it’s just applying the evidence given by knowing how old you are.
Are you saying it’s only true if you learn how old you are and you didn’t already know? Even if you already knew, there’s still P(you’ll die at 40) and P(you’ll die at 40|you’re 20). The former isn’t really useful in of itself, but it works as a good sanity check. For example, if you insist P(you’ll die eventually|you’re 20) = 50%, you’ll get P(you’ll die eventually) = 0%, along with P(you’re hallucinating that you’re 20) = 0%, etc. There is clearly something wrong here.
I could similarly tell you P(coin lands on heads) = 50%, even though I saw it land on tails, and P(coin lands on heads|I saw it land on tails) = 100%.
Incidentally, you can’t use whatever person you happen to be as a reference class without certain corrections. Also, you need the same corrections if you use descendants of Earth as a reference class.
I never said anything about aging. You also don’t have to assume you’ll ever die. I’m infinitely more likely to be 20 if I’ll die than if I won’t.
It wouldn’t apply if you don’t know how old you are, as it’s just applying the evidence given by knowing how old you are.
Are you saying it’s only true if you learn how old you are and you didn’t already know? Even if you already knew, there’s still P(you’ll die at 40) and P(you’ll die at 40|you’re 20). The former isn’t really useful in of itself, but it works as a good sanity check. For example, if you insist P(you’ll die eventually|you’re 20) = 50%, you’ll get P(you’ll die eventually) = 0%, along with P(you’re hallucinating that you’re 20) = 0%, etc. There is clearly something wrong here.
I could similarly tell you P(coin lands on heads) = 50%, even though I saw it land on tails, and P(coin lands on heads|I saw it land on tails) = 100%.
Incidentally, you can’t use whatever person you happen to be as a reference class without certain corrections. Also, you need the same corrections if you use descendants of Earth as a reference class.