Doug McIlroy wrote in <201910181152.x9IBq95P001809@coolidge.cs.Dartmouth\
.EDU>:
 |> 10-36-55.pdf    user-mode programs: pool game
 |
 |This game, written by ken, used the Graphic 2. One of its
 |earliest tests--random starting positions and velocities on
 |a frictionless table with no collision detection--produced
 |a mesmerizing result. This was saved in a program called
 |"weird1", which was carried across to the PDP11.
 |
 |Weird1 was a spectacular accidental demonstration of structure
 |in pseudo-random numbers. After several minutes the dots
 |representing pool balls would evanescently form short local
 |alignments.  Thereafter from time to time ever-larger alignments
 |would materialize. Finally in a grand climax all the balls
 |converged to a single point.
 |
 |It was stunning to watch perfect order emerge from apparent
 |chaos.  One of my fondest hopes is to see weird1 revived.

Not about random orders chaos, no, quite the opposite, but the
IOCCC context 2012 was won by endoh1, a fluid simulator using
"Smoothed-particle hydrodynamics (SPH)", and the "marching
squares" algorithm to render particles.  If the defaults for
gravity (1 -> 0), pressure (4 -> 1) and viscosity (8 -> 2) are
changed entertaining effects can be seen.

It is like swirling, not self-organizing order out of chaos, but
i wanted to post it nonetheless because of some properties of the
code, for example the IOCCC Makefile introduces "make love", may
also echo "You are not expected to understand this", and what else
can be expected.  The xxx.txt is an input file i made for this
post, the competition ones are neat (a fountain, for example), but
for normal gravity etc.

  $ make endoh1_color
  $ ./endoh1_color < xxx.txt

And spend some time.

 |Doug
 --End of <201910181152.x9IBq95P001809@coolidge.cs.Dartmouth.EDU>

--steffen
|
|Der Kragenbaer,                The moon bear,
|der holt sich munter           he cheerfully and one by one
|einen nach dem anderen runter  wa.ks himself off
|(By Robert Gernhardt)