Å·±¦ÓéÀÖ

“There’s a cellular automaton called TVC. After Turing, von Neumann and Chiang. Chiang’s version was N-dimensional. That leaves plenty of room for data within easy reach. In two dimensions, the original von Neumann machine had to reach further and further - and wait longer and longer - for each successive bit of data. In a six-dimensional TVC automaton, you can have a three-dimensional grid of computers, which keeps on growing indefinitely - each with its own three-dimensional memory, which can also grow without bound.

And when the simulated TVC universe being run on the physical computer is suddenly shut down, the best explanation for what I’ve witnessed will be a continuation of that universe - an extension made out of dust. Maria could almost see it: a vast lattice of computers, a seed of order in a sea of random noise, extending itself from moment to moment by sheer force of internal logic, “accretingâ€� the necessary building blocks from the chaos of non-space-time by the very act of defining space and time.”
― Greg Egan, Permutation City

“The TVC universe will never collapse. Never. A hundred billion years, a hundred trillion; it makes no difference, it will always be expanding. Entropy is not a problem. Actually, ‘expandingâ€� is the wrong word; the TVC universe grows like a crystal, it doesn’t stretch like a balloon. Think about it. Stretching ordinary space increases entropy; everything becomes more spread out, more disordered. Building more of a TVC cellular automaton just gives you more room for data, more computing power, more order. Ordinary matter would eventually decay, but these computers aren’t made out of matter. There’s nothing in the cellular automaton’s rules to prevent them from lasting forever.

Durham’s universe - being made of the same “dustâ€� as the real one, merely rearranged itself. The rearrangement was in time as well as space; Durham’s universe could take a point of space-time from just before the Big Crunch, and follow it with another from ten million years BC. And even if there was only a limited amount of “dustâ€� to work with, there was no reason why it couldn’t be reused in different combinations, again and again. The fate of the TVC automaton would only have to make internal sense - and the thing would have no reason, ever, to come to an end.”
― Greg Egan, Permutation City