[extropy-chat] three coins in a fountain.

[John K Clark]

"Eliezer S. Yudkowsky" <sentience at pobox.com>

> Probabilities exist in the mind, not in reality.

Before the quantum revolution we could say that with great confidence,
now I'd say the probability is it's probably untrue that probabilities exist
in the mind, not in reality. Probably. I think.

>  There is no such thing as the probability of a probability.

But there does exist the square root of a probability, it's the quantum wave
function; And being a square root means it can and does have negative terms
in it and even imaginary terms, and that means the quantum wave function is
not a scalar like simple probability but a vector with an intensity and a
direction, and that means you can not just add up 2 independent
probabilities to figure the probability that both will happen the way we
usually do, and that means two very different wave functions can yield the
same probabilities, and that means we can't do things the way common sense
would dictate. And that's why the quantum world is so weird.

  John K Clark