Thx so much for the link above!
Since I am not a scientist I didn't know about the inverse problem, but I had thought about that intuitively.
I think it's true that a current state of an atom, in a 3 dimensional context, may be achieved through multiple histories or even manipulated by a living being who wants to "cheat the system".
But in a 4 dimensional context, where the coordinates on a base field (maybe Higgs field), which could also be called time, are included, that would eliminate the possibility of recreating the same position for different stories since time happens only once, in a forward motion, and thus making that state unique and irreplaceable.
I think a position of height x, width y, and depth z is replicable the way you say above.
But, is a position of height x, width y, depth z, at time w (considering a single time line since the big bang) replicable?
If yes then the inverse problem refutes my original idea in this thread, if not IMO it is still possible to reverse-understand the universe that way.
Ah, hmm.... Maybe! If you include the entire history of the atom, then I'm not actually sure. That's a tough question, and a good question =)
One of the themes of current scientific progress is getting more and more information out of tiny amounts of data. Who'd have thought that we could learn so much of distant and recent biological history from DNA, and so much about distant planets, stars, galaxies, and the cosmos from tiny differences in very small amounts of light?
Pratchett's death puts an extra edge on the question-- to what extent can people be re-created from what they've left behind them, especially if they've written novels which include a lot of their personality?
Any thoughts about theoretical limits of how much can be figured out from small amounts of data?