> I have a question that keeps going back and
>forth in my mind, and I'd like to get your
>opinions on it. This is all hypothetical, but
>lets just say we had a computer with an infinite
>capacity for data. Also assume that all the
>physical laws governing the universe were put in
>to this computer. Also assume that the computer
>has inside of it ALL of the data for one moment
>in time, and only one moment in time. (Where
>everything in the universe is, it's velocity,
>mass, everything) Would this computer be able
>to, using the physical laws it has in it, know
>all the information for the past and future as
>well?

No. The reason is because it's not possible, even in theory, to know all the relevant statistics of even *one* particle of matter at any one moment of time to arbitrary precision. Every measurement you make of any one variable (such as position, velocity, or mass) disrupts the value of some other variable in some non-predictable way. I don't know how better to explain it other than to say that no physicist ever talks about the absolute position of, say, an electron. You can only speak of probability ranges of where it most likely is. And this has nothing to do with not having precise enough measuring equipment, and everything to do with how the Universe is structured.

So no, it's not possible to predict the future or know the past with 100% certainty, even in theory. You can thank Max Planck and the rest of the Quantum gang for that one.

-- Dave