Game of Life News

Noam Elkies responded to the challenge of finding a period-4 glider reflector by designing a new type of 180-degree reflector based on a spark-assisted block reconstruction. Jason Summers built a faster version at p22 (upper right), which produces a glider on the same path two ticks earlier.

The original reflection reaction can work at higher periods; variants are shown at right with p6, p7, and p8 sparks. The reflection path is the same as a kickback reaction, but the timing is different. By comparison, a pentadecathlon-based kickback emulator (far right) is four ticks faster -- or four ticks slower, since timing can be adjusted mod 8 by changing the reflector's location.

David Eppstein contributed a p4 oscillator that could accomplish the same catalysis as the p22 oscillator above; improved versions are shown in the period 4 and period 8 reflectors at right, cleaning up the extra debris in an Lx134 conduit.

Continue reading "New 180-degree glider reflector, period 4 and up"

Posted by Dave Greene at 02:02 | Permalink

Nicolay Beluchenko has found the first known ^c/₆ Diagonal Spaceship.

(A list of known spaceship speeds)

Posted by HKoenig at 21:57 | Permalink

Gabriel Nivasch has announced the construction of a spaceship which travels at the speed of ^17c/₄₅. It is based on a "Pi Crawler" reaction, where a Pi Heptomino moves up a string of Blinkers leaving the string undisturbed. This means that multiple Pi Crawlers can use the same string of blinkers, and if multiple tracks are properly positioned, they can interact with each other to act as glider puffers or rakes. These gliders can then be used to create ^c/₂ Orthogonal Spaceships which in turn can run ahead of the Pi Crawlers and lay down the necessary Blinker tracks. For more information on how all this works, see Nivasch's earlier report on the Caterpillar components.

The spaceship itself has a period of 270, and is huge. The dimensions are 4195 cells wide by 330,721 cells deep. Starting with a population of 11,967,399, ranging from 11880063 (gen 113) to 12019156 (gen 210). Nivasch reports that he wrote a program which fitted together 51 different .rle subpatterns that make up the Caterpillar into the final, working pattern. This is the first known spaceship which travels at this speed (0.378c), and the largest object ever actually constructed to date.

Jason Summers has made available a zipped 7.1Meg copy of the .rle file, It has been reported that this .rle file will successfully load and execute with the Life32 program by Johan Bontes, or with Hashlife by Tomas Rokicki. With Life32, just wait a bit for it to load, and be sure to zoom down to a reasonable subsection of the entire pattern, otherwise each generation will take an inordinate amount of time to display. Properly zoomed down, it only takes about a second per generation.

Update: 2005-Jan-03

Gabriel Nivasch has updated his web page to provide a 1:40 scale illustration of the entire object.

Posted by HKoenig at 17:27 | Permalink