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  • Adam Goucher
  • Dave Greene

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2006 May 26

Puffers
Block Puffer

P8 Block puffer Hartmut Holzwart has found a new type of Period 8 Block Puffer.

2006 May 13

Wicks & Fuses
Zigzag Wickstretcher

2006-02-14-zigzag-stretcher.rle
zigzag c/2 orthogonal wickstretcher
Jason Summers, 14 Feb 2006
Back in February, Jason Summers constructed a complex assembly of c/2 orthogonal rakes that builds a zigzag wick. The pattern uses glider constructions similar to those found in David Bell's c/12 diagonal wickstretchers from last year.

Oscillators
Prime-Period Oscillator: p103079214841

2006-03-31-p103079214841.rle
p103079214841 (prime: 4^13*1536-263) oscillator/gun --
p1536 base loop, 13 quadruplers, and a 263-step glider advancer.
Dave Greene, 31 Mar 2006 (with correction by Tomas Rokicki)
Here is a sample Herschel-based oscillator with a 12-digit-prime period, along very similar lines as the 11-digit-prime oscillators constructed in 2003, but with alternative 'glider advancer' technology and more compact connecting circuitry.

Like the 2003 examples, this pattern consists of a Herschel/glider loop (period 1536 this time, instead of period 1450) attached to a series of thirteen 'quadrupler' conduits of two different types, L-shaped and straight. Each quadrupler allows only one Herschel signal in four to get through to the next conduit.

In the starting configuration, the first three quadruplers are set to absorb three signals each: an extra block has been added to the first two L112 quadruplers and the first Fx70 quadrupler, which has a standard F166 dependent conduit appended to suppress the following Herschel's first glider. So the circuit initially counts down from 63. When all circuits are empty, a signal gets through to activate the 263-step glider advancer -- after which the circuit counts down again, this time from 4^13-1.

As usual with this kind of Herschel-track construction, Karel Suhajda's 'Hersrch' search program was used to design the base loop, and to locate an efficient connecting circuit between the end of the quadrupler chain and the glider advancer. The continuing challenge, of course, is to fit an oscillator with a higher prime period into a bounding box with a smaller number of cells.

2006 May 12

Wicks & Fuses
More Puffer Orbits

Here's another batch of puffer orbits found by Jason Summers.

In the following tables, the percentages are approximate, intended to illustrate how common or rare a particular puffer might be. The bit patterns are not the actual puffer, but a simpler pattern which will eventually evolve into the puffer.


c/3 puffers The first puffer presented here is a based on a large Period 3 which moves at a speed of c/3. It also has a slightly smaller Period 12 variation.

P222+102≈97%
P114+3≈3%
306P3H1V00.04%
P273+1300%
P180+1610.005%
450+239trace
304P12H4V0trace


P28 puffers The next set of puffers are based on a Period 28 Spaceship.

213P28H7V099.94%
140+900.04%
P168+1090.02%
P56+14trace


P2 puffers Another pair of puffers are based on a Period 2 Spaceship previously used to create a Period 8 Glider rake, both of which are shown also.

P224+12499.98%
P32+70.02%


Tub puffers The final set includes a previously known B Heptomino based Tub puffer.

P24+499.87%
P12+70.13%
P2724+41530.02%

Oscillators
New Period 15 Oscillator

180P15 oscillator Nicolay Beluchenko has found a new Period 15 Oscillator which is based on a pair on interacting T-Tetrominos stabilized by sparks from 4 Period 3 Oscillators. A number of phases of the T-Tetromino pair resemble phases of the Pentadecathlon whose halves have been separated by a column.

Missing Files

Thanks to John Green for pointing out that a number of the RLE files in the Puffer Orbits would not download properly. In fixing the problem and reviewing other possible problems, I found several other bad links. Please let us know when those things happen. If you can't see the images, or get and run the RLE files, then a mistake was made and it needs to be fixed. Or you may be using a combination of browsers and operating systems with which we are unfamiliar and may not realize we are breaking.

Transcendental Objects
Quadratic Population Growth, Revisited

2006-03-11-Gotts-dots.rle
'Gotts Dots': sprouts its nth switchengine at t ~ 2^(24n-6) --
41 ON cells, growth rate O(t ln t)
Bill Gosper, 11 March 2006
Bill Gosper and Nick Gotts set some new records back in March, for patterns exhibiting quadratic growth starting from the smallest initial population. On March 11, Bill Gosper produced the starting configuration shown at right, which is closely related to patterns from his previous Golly experiments.

Golly screenshot of Nick Gotts' 'wedge' /  'GRoW'
26-cell quadratic growth pattern
Nick Gotts, 17 March 2006
A week later, based on this, Nick Gotts produced a 26-cell quadratic-growth pattern: a forward-glider-producing switch engine repeatedly overtakes a crystal formed by collision with sideways gliders produced by a c/12 rake assembly. When the switch engine reaches the crystal, a reaction produces a orthogonal block-laying switch engine and restarts the crystal production at the c/12 rake boundary.

Golly screenshot of 'wedge' /  'GRoW' at ~3.5M ticks
Here is what the 26-cell pattern looks like after ~3.5 million generations:

Extensible Spaceships
Diagonal Greyships

2006-04-13-diagonal-greyship.rle
extensible diagonal c/4 1/3-ON parallelogram/trapezoid greyships
Nicolay Beluchenko, 13 April 2006
Nicolay Beluchenko created some sample diagonal greyships in various shapes, with a "grey" level of 1/3 ON cells (instead of the usual 1/2 for orthogonal greyships with 'stripes' or 'chicken-wire' agars.) Since these new "ships" are really an independent series of tubstretchers and tubeaters packed together as closely as possible, it's obviously possible to move the pieces farther apart from each other to produce lower fractions of ON to OFF cells.

It may also be possible to construct extensible multi-tubstretcher and multi-tubeater spaceships that support this agar -- where each stretcher or eater is connected directly to the next one, and can't be separated -- but this has not been accomplished as yet. Multistretchers and multieaters with wider spacings have been previously posted, however.

2006-04-13-diagonal-greyship2.rle
extensible diagonal c/4 1/3-ON rhombic greyship
Nicolay Beluchenko, 13 April 2006
Tubstretcher-based patterns composed of more than 1/3 ON cells are not possible. Thus, to produce a diagonal greyship that maintains a 1/2-ON agar, it would be necessary to devise diagonally moving extensible patterns that stabilize the edges of some other type of agar -- either an oscillating agar, or an extensible series of waves (moving wicks), or perhaps an orthogonally symmetric stable pattern -- most likely the 'stripes' agar.

However, since the stripes are not diagonally symmetrical, each of the edges would need a different type of support. Whether such a construction is possible is currently an open question. The main problem is that diagonal spaceships could not repeat at period 4, because each stripe is two cells away from the previous one -- so p8 spaceships would be needed.

Unfortunately p8 is not really within reach of currently available Life search programs (mainly David Bell's 'lifesrc' and Jason Summers' ' WinLifeSearch' port). Some fairly large leaps in efficiency and/or CPU speed would be needed to make this a likely goal. [Readers are, of course, invited to prove this statement wrong -- or to supply the necessary advances in search technology.]

2006 May 11

Spaceships
New Wave Spaceship Update

new c/4 diagonal spaceships: Nicolay Beluchenko, 7 April 2006
Nicolay Beluchenko and Hartmut Holzwart have created some interesting new spaceships of various shapes and sizes, by tying together pieces of new and previously known waves and wave terminations.

2006-02-16-c4-wick.rle
orthogonal c/4 (and 5c/2 and p36/9) wick, stabilized at c/4
Hartmut Holzwart, 16 Feb 2006

2006-04-07-wave-ends.rle
new terminations for Hartmut Holzwart's wave from March 2006
Nicolay Beluchenko, 7 April 2006

2006-03-21-wick-spaceship.rle
front and back joints for a moving (c/4 diagonal) wick posted by
Hartmut Holzwart, producing a stabilized modular c/4 spaceship.
Nicolay Beluchenko, 21 March 2006

2006-02-17-c4-wick.rle
smaller front stabilization for orthogonal c/4 wick
Nicolay Beluchenko, 17 Feb 2006

2006-02-17-t-tet-pushalong.rle
t-tetson pushalong: Nicolay Beluchenko, 17 Feb 2006

Here are separate commented files for Beluchenko's previous wave-based spaceships in this series, from 7 April 2006, posted last month in a combined pattern:

spaceship made with wave ends
terminations for Hartmut Holzwart's second wave from March 2006
shorter front termination of Hartmut Holzwart's March wave
new wave composed of pieces of previously known waves

Greyships & Spacefillers
2c/3 perpendicular signals through 'stripes'

2006-04-24-2c3-agar-signal.rle
extensible signal that moves at
speed 2c/3 through 'stripes' agar,
at right angles to the stripes
Hartmut Holzwart, 24 April 2006
Hartmut Holzwart and Jason Summers have been looking at signals that can propagate through an infinite medium consisting of alternating ON and OFF stripes (the same agar as in the interior of standard greyships).

It was shown in 1993 that signals travelling parallel to the striped medium must move at the speed of light -- but it turns out that non-destructive signals perpendicular to the stripes are also possible, and these follow different rules. In particular, they can move at a speed of 2c/3 orthogonally, slower than lightspeed but faster than a spaceship can travel through vacuum.

2006-05-09-2c3-extend-signal.rle
extensible symmetric 2c/3 orthogonal
signal in 'stripes' medium
Hartmut Holzwart, 9 May 2006

2006-05-09-2c3-agar-signal.rle
small symmetric 2c/3 orthogonal
signal in 'stripes' medium
Hartmut Holzwart, 9 May 2006

2006-04-15-2c3-agar-signal.rle
minimal 2c/3 stripe-crossing signal
in 'stripes' agar, based on
Hartmut Holzwart's larger original
Jason Summers, 15 Apr 2006

2006-05-02-2c3-agar-signals.rle
two short wide 2c/3 signals
Hartmut Holzwart, 2 May 2006

2006-04-28-2c3-agar-signal.rle
small 2c/3 signal in 'stripes' agar
Hartmut Holzwart, 28 Apr 2006

2006-04-26-2c3-agar-signal.rle
small symmetric 2c/3 signal
perpendicular to striped medium
Hartmut Holzwart, 26 April 2006

2006-04-26-pseudospacefiller.rle
unfinishable spacefiller fragment with a higher growth rate
than is attainable in vacuum
Hartmut Holzwart, 26 April 2006