# twenty-ten

*'There's a cellular automaton called TVC. After Turing, von Neumann and Chiang. Chiang completed it around twenty-ten; it's a souped-up, more elegant version of von Neumann's work from the nineteen fifties.'*

...

She said, 'Chiang's version was three-dimensional, wasn't it?'

'Much better. N-dimensional. Four, five, six, whatever you like. That leaves plenty of room for data within easy reach.'

...

In the throes of reproduction, each processor could be seen sprouting hundreds of pairs of fine red and green 'construction wires', which grew straight out into the surrounding empty space - until they all reached the same predetermined length, abruptly turned a tight one-hundred-and-eighty degrees, and then started growing back in the opposite direction.

...

In close-up, the wires resolved into long lines of cells marked with arrowheads, some rendered in the brighter hues which represented activated states.

...

She said, 'Chiang's version was three-dimensional, wasn't it?'

'Much better. N-dimensional. Four, five, six, whatever you like. That leaves plenty of room for data within easy reach.'

...

In the throes of reproduction, each processor could be seen sprouting hundreds of pairs of fine red and green 'construction wires', which grew straight out into the surrounding empty space - until they all reached the same predetermined length, abruptly turned a tight one-hundred-and-eighty degrees, and then started growing back in the opposite direction.

...

In close-up, the wires resolved into long lines of cells marked with arrowheads, some rendered in the brighter hues which represented activated states.

-- Permutation City by Greg Egan

As far as I know, this is the only appearance in fiction of von Neumann's cellular automaton. You can see the 'arrowheads' and 'construction wires' and 'brighter hues' here:

Of course, 2010 has come and gone and Chiang's version didn't appear. A guy called Will Stevens did make a 3D version of the CA in 2010, which is pretty awesome. Here it is making a copy of itself:

Also in 2010, Adam Goucher worked on a replicator in my own 'souped-up' version of von Neumann's rule. It looks like this:

And replicates like this:

And there were other exciting developments in the field too. As I've mentioned here before, we only got these 1950's patterns running in 2008, so it's pretty remarkable that Greg Egan was able to predict that from 1994!

* Will Stevens gave a talk at ALife 12 on his machine. More details here.

* Adam Goucher's machine is Boustrophedon-replicator, in the JvN folder in Golly.

* Greg Egan is still updating his FAQ on the book.

This post was originally on LiveJournal.