Stable Life?

[Haycat2009]

Dave Greene discovered a counter-example to popular belief, IceNine, a massive seed that grows very slowly, quadratically, and unstoppably. This is characteristic of a rule like Seeds or 34 Life, except IceNine requires a much larger critical mass (about 10 megapixels). Yes, this does grow irregularly, without using puffers or guns.

More surprisingly, IceNine emerges (and takes over) every arbitrarily large random universe. This could technically classify Life as being an 'chaotically expanding' rule. (!)


And that proves that Wolfram's classification of cellular automata doesn't work - a rule can behave differently at different scales. This is analogous to how the microscopic world is subject to quantum mechanics; the macroscopic world is instead controlled by general relativity.


Unfortunately, both IceNine and the program used to find it have mysteriously disappeared, and the only online copy (a 11.9 MB RLE file) was censored as non-standard text, suspected to be a virus.

The only way of finding it is to run an immense universe for ages in a powerful Life simulator until it emerges. Don't try this at home.

Dave Greene found it using a special-purpose program he wrote, which he coined the 'alternate-universe oscilloscope'.

On Feb. 23, 2008, Dave Greene wrote:

Every sufficiently large and ancient B3/S23 universe observed so far
turns out to be full of this weird agar, which expands in all
directions through random ash at c/137. IceNine seems to absorb
blocks and blinkers particularly well, due to a complicated froth of
sparks at its front lines -- not generated by glider collisions, but
by a lucky accident of the agar's internal structure.

When the expanding front touches an active pattern that it can't
immediately annihilate, the pattern "dies back" a short distance at
near lightspeed, leaving behind a protective scattering of blocks;
behind the blocks the front stabilizes and starts expanding again.
Converging IceNine fronts usually cause small diebacks that stabilize
as small defects in an apparent quasicrystalline structure.

And before you all ask, my alternate-universe oscilloscope was
repossessed by the Outsiders the other day, so unfortunately I can't
lend it out. But there didn't seem to be anything but IceNine out
there anyway --

Why do all of dvgrn's jokes travel at c/137?

[confocaloid]

https://en.wikipedia.org/wiki/Fine-stru ... asurements
https://physics.nist.gov/cgi-bin/cuu/Value?alphinv

https://physics.nist.gov/cgi-bin/cuu/Value?alphinv

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