Site Info

Authors
  • H.Koenig
  • Adam Goucher
  • Dave Greene

Main

2010 January 31

Methuselahs
Update: new territory for Online Soup Search

2010-01-31-edna-methuselah.rle
31192-tick methuselah "Edna", 10 January 2010
found by Erik DeNeve using Nathaniel Johnston's online soup search
On January 10th, Erik DeNeve broke a long-standing record for long-lived 20x20 patterns. Using Nathaniel Johnston's Online Soup Search utility, he found a pattern that takes over 31,000 ticks to stabilize. He christened it "Edna", after Methuselah's wife. The previous record-holder, Andrzej Okrasinski's Lidka, lasted 29,055 ticks, but has considerably fewer ON cells in its initial state.

Continue reading "Update: new territory for Online Soup Search" More

2009 August 31

Discovery
Progress of the Online Soup Search

Over the last couple of months, Nathaniel Johnston's Online Soup Search for Conway's Life has been hunting for 20x20 random "methuselah" patterns, using a modest-sized distributed network -- a good fraction of the spare CPU cycles of perhaps a dozen computers. As of the end of August, the conwaylife.com server has tallied the final stabilizations of over 111 million random 20x20 Conway's Life "soups", totaling over three billion Life objects (still-life, oscillator, or spaceship). This is slowly approaching the scale of Achim Flammenkamp's earlier random-ash census project from a decade and a half ago -- which represented an impressive amount of dedicated CPU time for 1994.

Version 1.03 of the soup-search script is now available. It's a Python script that will run on the current version of Golly for Windows, Mac, or Linux. Version 1.03 displays much more detail about the progress of the current search.

Methuselah survival times appear to fit a simple inverse exponential sequence. Lifespans between 1000(N-1) and 1000N are about twice as frequent as lifespans between 1000N and 1000(N+1) -- for a wide range of N. Version 1.03 of the script continuously updates an on-screen table of these frequencies, starting at N=5. It is an open question how far this relationship continues, or whether a larger sample will yield a more precise approximation of the curve.

Continue reading "Progress of the Online Soup Search" More

2007 January 30

Glider Constructions
Natural Clock

17.101-L-7 My ongoing project of going through collisions of a Glider with 16 and 17 bit stable objects looking for those that might be useful in object construction has found something else interesting. For the first time, I've come across a methuselah pattern that generates a natural, non-trivial Clock. The starting pattern is a Glider colliding with a 17-bit object. The Clock appears at generation 864, while the pattern finally settles down at 1507 generations

In the past, some of my large random pattern surveys turned up the occasional Clock, but whenever I looked closely at them, all that were examined showed that the Clock formed in the first generation or two and then somehow managed to survive all the turmoil of the next few thousand generations. I don't remember ever seeing one that appeared midway or late in a pattern's evolution.

Clock ConstructionJason Summers took one of the predecessor generations and was able to produce a six-Glider construction which cleanly builds a Clock in 52 generations.

Clock ConstructionClocks can be constructed with as few as four Gliders, and a few constructions from other objects are also known.

2005 July 14

Methuselahs
New Record Methuselah

Andrzej Okrasinski has found a new methuselah record holder, a 15 bit intial pattern with a final population of 1623 after 29053 generations. David Bell quickly found a 13 cell predecessor, bringing the record to 29055.

Some of the more unusual objects which make an appearance but which aren't in the final census include a Lightweight Spaceship [9P4H2V0.1], a Fishook Eater [7.3], a Long Barge [8.9], a Big S [14.492], a Bi-Pond [16.2630] and an unnamed 13 bit object [13.182].

Size Discoverer Gens Final Pop. Final Pattern, Census
13 13 Bit Methuselah
[David Bell]
29055 1623 15 Bit Methuselah
102(4.1), 2(4.2), 15(5.1), 6(6.2), 57(6.4), 1(7.2), 18(7.4), 5(8.7), 2(12.41), 135(3P2.1), 1(6P2.1), 1(6P2.2), 28(5P4H1V1.1)
15 15 Bit Methuselah
[Andrzej Okrasinski]
29053

Note: Not all of the paths of escaped gliders are shown.

2005 February 21

Methuselahs
New Methuselah Records

Tomas Rokicki has announced some of the results of a survey for methuselahs. The table below shows the record holding patterns for given bit sizes. More information can be found at his webpage. Other information about methuselahs, can be found at Dean Hickerson's website. Andrzej Okrasinski also announced his finding of the current record holding pattern.

Size Name Gens Final Pop. Final Pattern, Census & Discoverer
r pentomino
r Pentomino
1103 128 r pentomino
8(4.1), 1(5.1), 1(6.2), 4(6.4), 1(7.4), 4(3P2.1), 6(5P4H1V1.1)
5 r pentomino 1105
6 r pentomino 1108
7 Acorn
Acorn

[Charles Corderman]
5206 633 Acorn
34(4.1), 8(5.1), 3(6.2), 30(6.4), 2(6.5), 5(7.4), 2(8.7), 1(8.8), 41(3P2.1), 13(5P4H1V1.1)
8 New Methuselah
[Tomas Rokicki]
7467 952 New Methuselah
51(4.1), 2(4.2), 11(5.1), 4(6.2), 35(6.4), 16(7.4), 2(8.7), 1(14.475), 61(3P2.1), 1(6P2.1), 24(5P4H1V1.1)
Bunnies
Rabbits

[Andrew Trevorrow]
17331 1749 Bunnies
109(4.1), 4(4.2), 18(5.1), 7(6.2), 65(6.4), 18(7.4), 3(8.7), 136(3P2.1), 2(6P2.1), 40(5P4H1V1.1)
9 Bunnies9
[Paul Callahan]
17410
10 Bunnies0
[Tomas Rokicki]
17423
11 Bunnies11
[Tomas Rokicki]
17465
12-18 New Methuselah
[Tomas Rokicki]
23334 2898 New Methuselah
207(4.1), 7(4.2), 23(5.1), 12(6.2), 115(6.4), 2(7.2), 32(7.4), 4(8.7), 171(3P2.1), 1(6P2.1), 2(6P2.2), 70(5P4H1V1.1), 1(9P4H2V0.1)
19 New Methuselah
[Andrzej Okrasinski]
28786 3091 New Methuselah
196(4.1), 6(4.2), 31(5.1), 9(6.2), 143(6.4), 3(6.5), 34(7.4), 6(8.7), 2(12.41), 1(14.475), 213(3P2.1), 47(5P4H1V1.1)

Note: Not all of the paths of escaped gliders are shown.