Game of Life News

Last Posting

2006-03-05T10:22:00.000-08:00

Notice:

This will be the last posting for this site. It's moving to a new location:

http://pentadecathlon.com/lifeNews/index.php.

All the old posts have been moved there. Update your links and bookmarks as appropriate. For now, everything here will be left as is. Eventually, the images will disappear as part of a website update on the hosting server.

Website Update Announcement

2006-02-28T14:59:00.000-08:00

Stephen Silver has made available an update (Version 25) to his Life Lexicon.

Various New Oscillators

2006-01-30T13:15:00.000-08:00

Scot Ellison has found a new Period 7 Sparker.

Nicolay Beluchenko found a much smaller Period 4 super-fountain style oscillator, and then managed to shrink it further.

A fountain-type oscillator is one which has a phase in which a spark is separated from the body of the oscillator by several cells distance. The maximum possible distance is the oscillator's period less one. These isolated sparks make the oscillators useful in guns and other engineered objects.

Beluchenko also has found a Period 4 Oscillator component (which comes in two varieties) which can be supported by Period 2 components.

By using Period 2 components to connect them, any number of these Period 4 components can be combined to create wicks and rings.

He also found another set of Period 4 Oscillators whose halves can be recombined in various forms.

And finally one last small Period 4 Oscillator.

New Long Period Oscillators

2006-01-11T11:10:00.000-08:00

Jason Summers has found a few new long period oscillators. First is a Period 22 Oscillator whose basic rotor can be repeated. Shown beside the simpliest version is an extended example.

He has also found a Period 14 Oscillator and a Period 27 Oscillator with similar rotors.

"Rule 110" Unit Cell

2005-12-21T12:51:00.000-08:00

Jason Summers has put together a "Rule 110" unit cell. A unit cell is a Game of Life pattern which acts as if it were a cell or component in another automata, allowing the Game of Life to incorporate the abilities and results of that automata into itself. For example, several years ago David Bell created a Life unit cell which can be used to recursively simulate the Game of Life.

"Rule 110" is a 1-dimensional non-totalistic cellular automaton. A cell's next state depends on its current state and the states of its two nearest neighbors, as follows:

Gen 0	Gen 1
000	.0.
001	.1.
010	.1.
011	.1.
100	.0.
101	.1.
110	.1.
111	.0.

From Summers' description of his pattern:

The logic used in the pattern is (B AND NOT A) NOR (B XOR C), where A is the cell to the left, B is the cell itself, and C is the cell to the right. This produces the inverse of the correct rule-110 result. The result is then put through various duplication, reflection, and inversion reactions to produce four copies of an uninverted signal. One copy is sent to the cell on the left, one to the cell on the right, one is fed back into the same cell, and one is emitted upward as a visual record of the cell's states.

That the horizontal spacing (256) is a power of 2 is intentional, and might make it more efficient to run in Hashlife. The period (1200) can't reasonably be made a power of 2.

It should be easy to adjust the period by multiples of 120 generations, and the horizontal spacing by multiples of 60 cells. Other adjustments are possible, but more difficult.

As Summers notes, it would be an interesting project to build a puffer which lays down these unit cells as its output, and do so at a rate faster than they'd be needed by the "Rule 110" automata run.

Image Key:

A: Marker Tubs and initial Block
B: Glider->Spaceship reaction
C: Spaceship->Glider reaction
D: Turn Glider 90°
E: Invert & turn Glider 90°
F: Split stream
G: Duplicate stream

Red: Input streams
Green: Output streams
Blue: Internal streams

Unlabeled are a couple of signal generator Glider Guns and a couple of Fishook Eaters which are a part of the logical operators. The objects in the corners are used for alignment of multiple cells.

Using the pattern:

To use the pattern, place copies such that the "decorative still-lifes" at the corners coincide. The initial state of the cell is forced to be ON by the glider located between the tubs (A in the pattern). Remove the block infront of it to set the cell state to OFF. If the Fishook Eaters on the left and right edges don't disappear on their own in a few generations, then they can be removed manually before starting. For Game of Life programs that don't like the annotation format commands, a file without the formatting is also available

Fixed-Width and Slipping-Stripe Greyships

2005-12-18T19:46:00.000-08:00

fixed-width 2c/4 spaceship supporting a p9 wick
Hartmut Holzwart, 15 December 2005

Here are a few more greyships and related patterns constructed recently by Hartmut Holzwart:

long and short versions of a fixed-width perpendicular greyship
Hartmut Holzwart, 13 December 2005

simpler fixed-width perpendicular greyship
Hartmut Holzwart, 13 December 2005

The following two patterns are "failed spacefillers" -- they expand in the same way as a standard spacefiller for a while, until an internal instability in the boundary between the two types of stripes catches up with an expanding edge.

alternate mirror-symmetric pattern showing Gabriel Nivasch's
slipping-stripe reaction: Hartmut Holzwart, 28 November 2005

trial pattern showing a slipping-stripe reaction sent in
by Gabriel Nivasch: Hartmut Holzwart, 21 November 2005

These last two patterns, along with many of the greyships from previous postings, can also be seen here in MCell holiday colors.

Switch-engine breeder

2005-12-18T15:36:00.000-08:00

Switch-engine breeder: David Bell, 23 July 2005

Back in July, David Bell constructed a new switch-engine breeder. An orthogonal c/2 rake shoots gliders at the detritus left by a diagonal c/4 puffer, resulting in a 'natural' reaction that produces c/12 block-laying switch engines.

Sample c/5 and c/4 glider-processing convoys

2005-12-18T08:29:00.000-08:00

c/5 puffer converted into a (relatively) small p1080 rake. Add
two gliders to the loop to get p360. David Bell, 28 October 2005

Here are four patterns by David Bell, showing a variety of ways (some discovered relatively recently) for passing spaceships to affect an active pattern. The first is an engineless p1080 rake, using a design similar to the recently-posted p360 spaceship:

diagonal c/4 convoy turns a sideways glider into a forward LWSS: David Bell, 11 November 2005

The next three patterns involve diagonal c/4 convoys (spaceships that travel the same speed as a glider, but have sufficiently isolated edge sparks that they can interact non-destructively with gliders and other active patterns.) Here are some sample convoys that process input gliders to produce various types of output:

diagonal c/4 convoy which converts a single sideways glider into a toad. A toad in combination with other nearby stable/p2 patterns
(e.g., 6bo$6bobo$6boo3$11b3o$12b3o3$3o$bbo$bo!) can be converted to a backward or sideways glider by a passing convoy,
making it useful as a 'memory bit'. David Bell, 12 November 2005

Period doubling reaction for diagonal c/4 rakes, demonstrated with a p800 glider stream. Diagonal c/4 rakes are constructible
with period 28, 24, 16, or 0 (mod 32). David Bell, 2 November 2005

New perpendicular greyships

2005-12-16T09:36:00.001-08:00

perpendicular-to-the-grain greyship with new back slope
Hartmut Holzwart, 29 November 2005

Hartmut Holzwart has incorporated a variety of new reactions, slopes, and overall shapes into perpendicular ("against-the-grain") greyships. Here is a sampling:

new greyship component shown on right side
Hartmut Holzwart, 29 November 2005

mirror-symmetric against-the-grain greyship with new back slopes
Hartmut Holzwart, 2005-11-30

perpendicular greyship with 1/4 back slope
Hartmut Holzwart, 1 Dec 2005

pentagonal perpendicular greyship with 1/4 back slope
Hartmut Holzwart, 1 Dec 2005

new perpendicular greyship with central wick from an old unfinished
spacefiller: Hartmut Holzwart, 6 December 2005

perpendicular greyship with 1/2 back slope
Hartmut Holzwart, 7 December 2005

perpendicular greyship with even symmetry -- new back slope,
front end from a spacefiller: Hartmut Holzwart, 5 December 2005

greyships suggested by Gabriel Nivasch, with stripes offset by one
down the middle: Hartmut Holzwart, 7 December 2005

sample greyship-based puffer: Hartmut Holzwart, 2 Dec 2005

two even-symmetry perpendicular greyships chained together, with
small tagalongs at back end: Hartmut Holzwart, 5 December 2005

Hybrid greyships (perpendicular and parallel stripes)

2005-12-16T09:10:00.000-08:00

hybrid 2c/4 greyship: Hartmut Holzwart, 16 November 2005

Another recent new idea in the greyship line is the combination of perpendicular and parallel direction of travel ("with-the-grain" and "against-the-grain" ships) into the same greyship, with various interfaces between the striped regions. These, like previous greyships, can have arbitrarily large grey regions -- though it's somewhat trickier to change the size in some of these cases, since the phases of several edge and interface terminations must be synchronized.

alternate hybrid 2c/4 greyship: Hartmut Holzwart, 16 November 2005

hybrid greyship: Hartmut Holzwart, 18 November 2005

triangular hybrid greyship: Hartmut Holzwart, 23 Nov 2005

greyship showing new components: Hartmut Holzwart, 25 Nov 2005

hybrid greyship with a crooked internal boundary
Hartmut Holzwart, 8 December 2005

variation of the base template: sample asymmetric hybrid greyship
Hartmut Holzwart, 18 November 2005

symmetric hybrid greyship: Hartmut Holzwart, 18 November 2005

Object Miscellany

2005-12-11T13:12:00.000-08:00

Here a number of new Game of Life objects discovered in the past few months, in no particular order:

A Period 360 ^c/₅ spaceship found by David Bell. Removing one or two of the circulating gliders gives a Period 1080 spaceship instead

Nicolay Beluchenko has found a 20 bit variant on a known Period 3 oscillator.

Scot Ellison has found a set of Period 7 Oscillators, one as small as having a population of 38 Bits, which have some isolated sparks in one of their phases.

A pair of Diagonal ^c/₄ Double Wickstretchers found by Nicolay Beluchenko.

A tagalong for the recently discovered Diagonal ^c/₆ Spaceship, found by Nicolay Beluchenko.

Extensible spaceships

2005-12-10T14:48:00.000-08:00

long and short c/3 ships with central p15/5 wick
Hartmut Holzwart, 7 December 2005

Over the past few months, Hartmut Holzwart has constructed a series of spaceships with a variety of shapes, periods, and velocities. The majority have been "greyships" of different types -- but here is a random sampling of ships that don't fit neatly into that category:

extensible thin orthogonal 2c/4 spaceship
Hartmut Holzwart, 16 November 2005

extensible p3 spaceship: a p22 wick stabilized by c/3 ships
Hartmut Holzwart, 14 November 2005

pure p12 glide symmetric tag, attached to a two-section
p2 front end: Hartmut Holzwart, 28 Oct 2005

long and short c/3 ships w/ central p14 wick, based on a ship from
Jason Summers' raw c/3 collection: Hartmut Holzwart, 14 Nov 2005

asymmetrical c/3 greyship: Hartmut Holzwart, 11 November 2005

New P7 sparker

2005-11-26T16:09:00.000-08:00

P7 oscillator with a weak spark (glider deletion due to David Eppstein)

Toward the end of October, Scot Ellison published a new oscillator with a weak P7 spark:

Though no uses have been found for this particular pattern as yet, oscillators that can delete gliders can sometimes be useful for specialized signal processing. One example is in low-period Herschel conduits. The FNG (first natural glider) released by a moving Herschel is often the key factor determining the allowable "compression" of a circuit: a second Herschel can't pass through most conduits until after the glider from the previous Herschel has gotten out of the way. In some cases, an oscillator can "reach in" slightly and delete a glider more quickly, or in a tighter space, than a still-life eater can manage.

Adjustable Clean c/4 Glider Rake

2005-10-27T05:46:00.000-07:00

Some recently-discovered c/4 diagonal spaceships include accessible sparks, which can be used to make alterations to other active or stable patterns in passing. Recent discoveries include alterations that reflect gliders 180 degrees, or convert a single glider into multiple gliders -- along with a c/4 wickstretcher with a wick that can be ignited by gliders, where the resulting fuse can be timed to burn out without harming the wickstretcher engine.

David Bell has used these results to complete an adjustable clean c/4 rake, with periods of the form 4508+32N. Bell's description follows:

The rake has an engine convoy at the front, two convoys forming lines behind that, and a V-shaped convoy at the back. The recipe to create the next rake in the series is:

Move the top line convoy orthogonally right by 6 cells. Move the left line convoy orthogonally down by 6 cells. Move the V-shaped convoy diagonally back by 6 cells.

This will increase the period by 32 generations.

The modifications can be be made in the opposite direction to form the earlier rakes in the series. Moving the convoys by 300 cells creates the first rake in the series, having the period 4508.

New Period 7 Oscillators

2005-10-21T12:24:00.000-07:00

Scot Ellison has found some new Billiard-Table type Period 7 Oscillators.

New Oscillators

2005-10-21T11:21:00.000-07:00

Karol Suhajda has found a previously unknown Period 4 wick element, along with a stabilization of it.

He also found a new Period 6 Heavyweight Spacehip Emulator.

More new c/4 Diagonal Spaceships

2005-10-06T12:38:00.000-07:00

Harmut Holzwart has found a few new ^c/₄ Diagonal Spaceships.

Based on them, Nicolay Beluchenko then came up with another set of such spaceships by combining them with parts of other ships found earlier.

Application Announcement

2005-10-06T09:17:00.000-07:00

Tomas Rokicki has announced the release of a new version of Golly, the cross platform Game of Life program written by him and Andrew Trevorrow. From his announcement:

The important changes:

Saves patterns (RLE or macrocell formats).
Displays comments in pattern files.
Windows app can read gzipped pattern files.
Simple cell selection and editing.
Scrolling via hand cursor.
New tool bar buttons.
Numerous bug fixes and interface improvements.

The distribution now includes a pattern collection (still under development). Many of the current patterns show off Golly's hashing capabilities.

More new c/4 Diagonal Spaceships

2005-09-19T14:15:00.000-07:00

Here's another batch of new ^c/₄ Diagonal Spaceships that Nicolay Beluchenko has found.

Harmut Holzwart has extended a few of these new spaceships by adding some tagalongs for which there was previously no spaceship for attachment.

c/6 Diagonal Spaceship

2005-09-17T21:57:00.000-07:00

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

(A list of known spaceship speeds)

Grow-By-One Pattern

2005-09-10T12:18:00.000-07:00

In his continuing quest for Diagonal Spaceships, Nicolay Beluchenko has also found what is currently the smallest known "Grow-By-One" pattern. This type of pattern is one whose population growth rate is exactly linear, without any fluctuations, adding a single bit every generation. Shown here is a slight improvement by David Bell, which starts a generation earlier than Beluchenko's orginal pattern, with a population of 44 at generation 0. (The purpose of the Lightweight Spaceship is to smooth out the fluctuations in the paired wickstretcher's population.)

The second pattern shown here is a version which is also a single object (starting with a population of 53).

New longer period oscillators

2005-09-08T13:04:00.000-07:00

Jason Summers has found a couple of new longer period oscillators. One is fairly small, with a period of 22, the other has a period of 28 and requires some fairly large Period 7 oscillators to help stabilize it.

More new c/4 Diagonal Spaceships

2005-09-07T15:00:00.000-07:00

Nicolay Beluchenko has found another batch of new ^c/₄ Diagonal Spaceships. As before, these are all presented in no particular order.

Lineship Update

2005-09-06T10:27:00.000-07:00

On June 24th, David Bell produced an optimized version of Jason Summers' original lineship (shown in reduced scale at right -- click the thumbnail for the RLE, or here for a full picture). There have been several further developments along these lines.

Dave Greene used some of David Bell's new compact Cordership technology to produce a modified tail section for the revised lineship which repeats at p768 instead of at p96.

[The thumbnail at right shows only the modified tail section -- click here for a picture of the full pattern.]

David Bell followed this with a redesigned diagonal c/12 period 96 lineship. In this variant, the creation of the line at the front is done in pieces which are then welded together to form the line, using the repair techniques described in the "Cutting and Repairing Diagonal Lines" posting. The back end has also been reduced, since a sideways rake is not needed to ignite the line.

Again, only the smaller back end is shown in the thumbnail; a full-sized image is here.

The Cordership at the tail end of the adjustable-period lineship shown at right (full-sized image here) is responsible for igniting the stabilized end of line whenever it gets near to it. Nicolay Beluchenko points out that this Cordership could be adjusted by moving the trailing Cordership by multiples of 22 cells diagonally, rather than 88, if the front of the line were constructed in length-22 segments as well (but this would make the front of the ship much larger).

Greyship Update

2005-09-06T09:12:00.000-07:00

Hartmut Holzwart has constructed several new 2c/4 greyships (spaceships consisting primarily of alternating lines of ON and OFF cells -- see this previous post.) Here are two versions of a 2c/4 perpendicular greyship, in which the direction of travel is perpendicular to the alternating stripes, instead of parallel to them:

It's possible to shorten an arm of one of the above ships to get a triangle, as shown at right. Some further incomplete perpendicular-greyship results can be found here. Another triangle that uses some of these connections is shown at the far right.

Other greyship speeds are also possible. Here is a parallel greyship that travels at c/3 instead of c/2: