This week's featured article
|A Garden of Eden is a pattern that has no parents and thus can only occur in generation 0. The term was first used in connection with cellular automata by John W. Tukey, many years before Conway's Game of Life was conceived. It was known from the start that Gardens of Eden exist in Life because of a theorem by Edward Moore that guarantees their existence in a wide class of cellular automata. The first Garden of Eden was found by Roger Banks and the MIT group in 1971. It had a bounding box of size 33×9 and 226 cells. Jean Hardouin-Duparc found the second and third Gardens of Eden by computer search in 1973, which had bounding boxes of size 122×6 and 117×6. His goal was to find Gardens of Eden with minimal height. In April 2016, Steven Eker found a Garden of Eden fitting inside a 5×83 bounding box. It is known that no Gardens of Eden exist with height less than 4, but the question is still open for the h=4 case.
In the news
- April 11: David Raucci finds a new p76 pi-heptomino hassler oscillator, which is quickly reduced to a monomer form by JP21, A for awesome, and Matthias Merzenich.
- April 10-14: Goldtiger997 completes a 152-glider synthesis of a third c/4 orthogonal spaceship, 61P4H1V0.1; within four days this was reduced to an 89-glider synthesis.
- March 18: Results for the 2020 Pattern of the Year competition include a tie for first place between the Bandersnatch and the Speed Demonoid.
- March 17: A small synthesis efficiency improvement project, 12-in-7 (12-bit still lifes constructed with 7 gliders or less) is completed, with 13 expensive syntheses reduced to below the target cost in less than a week.
- March 17: Pattern of the Year voting, on a record-breaking thirty-nine entries for 2020, will close on March 17th.
- March 12: The 20-bit still life glider synthesis project is completed.
- March 7-8: Goldtiger997 completes a 215-glider recipe for 72P4H1V0, the second c/4 orthogonal spaceship to be synthesized.
- February 10-11: Chris Rowett uses ikpx2 to discover several new moving objects, including a p120 2c/5 puffer and c/5 diagonal tubstretcher, tagalong, and spaceship.
- February 4-11: Tanner Jacobi, EvinZL, Louis-François Handfield and Sphenocorona find new Herschel-to-glider converters and variants of existing H-to-Gs: NW26T157b, NE30T17_NE1T22, NW10T137, SW-18T136 and a Spartan SE16T36b.
- January 11-March 8: Hartmut Holzwart completes several new chicken wire greyships with different widths of chicken wire, with specific examples constructed for widths 2 through 12 among others.
|The LifeWiki contains one of the most comprehensive catalogues of patterns available on the internet. Within it you will find:
Did you know...
- ... that Gemini, the first spaceship found in Conway's Game of Life that travels in an oblique direction, was discovered in 2010?
- ... that there are still lifes (such as the quad pseudo still life) that can be split into four stable islands, but not two or three?
- ... that no new spaceship speeds were discovered after 1970 until 1989?
- ... that the first stable reflector was found in October 1996, and the first fast stable reflector appeared in 2013, allowing the construction of oscillators of all periods ≥43 ticks?
- ... that nineteen spaceship velocities have been constructed, excluding several infinitely adjustable families of ships?
- ... that there are 71 distinct ways for two gliders to collide, but it is unknown how many distinct 3-glider collisions there are?
- ... that to display the smallest known gun pattern for a Gemini spaceship at 1 cell = 1 pixel, on a standard-density video monitor, a screen over one mile square would be needed?
- ... that no odd-period glider guns were known before 1995, when a period 565 p5-spark-assisted B-heptomino loop was constructed by David Buckingham?
- ... that even though the speed limit for spaceships is c/2 in a vacuum, in a medium of stripes agar there are "spaceships" that can travel at lightspeed along the stripes, or two thirds of lightspeed perpendicular to the stripes?
- ... that the smallest known spacefiller pattern consists of 183 cells?