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  • Adam Goucher
  • Dave Greene

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2006 July 15

Agars
Period 16284 Agar

P19824 B Heptomino Agar Nicolay Beluchenko has found a B-Heptomino based agar. A 14 x 23 array takes 354 generations for the array to reappear shifted 6 cells and flipped horizontally. 708 generations are needed for an unflipped version to reappear shifted 12 cells vertically but none horizontally. The array will reappear in its initial position and orientations after 16,284 generations.

Edge stabilizers to convert this agar into a bounded oscillator is left as an exercise for the student.

Glider Constructions
House To Snake Conversion

Lightbulb One of the very first postings at the LifeNews weblog was for a construction of a Lightbulb with a House [26P2.2595] inductor by Mark Niemiec. He mentioned that it was not known how to construct the minimal case with a Snake [6.1] inductor ([23P2.753]), as shown at left. Noam Elkies has found a series of constructions that fill that gap when combined with construction components found over the years by David Buckingham, Mark Niemiec and H.Koenig.

House Inductor to Snake

Note: The sequence shown substitutes a House for the Lightbulb for simplicity, but none of the incoming Gliders will interfere with a range of objects with a 3-bit inductor surface.

Update: 12:45

19.24349 [47A] A further examination of the Contruction Component Catalog shows that there is a way to reduce the conversion of [19.24349] to [21.95471] from 8 Gliders to 6. Unfortunately, this construction will not work for the Lightbulb because the Glider coming in from the Northeast will hit it first, requiring the use of this 8 Glider conversion found by Elkies. A second conversion of only 4 Gliders (47B) won't work even for the House.

Spaceships
New c/5 Diagonal Spaceships

New c5 Diagonal spaceships Nicolay Beluchenko has found a few new c/5 Diagonal spaceships, including one, at 67 bits, which is the smallest currently known.

2006 July 08

Oscillators
New Period 4 Oscillator Type

New P4 Oscillators Nicolay Beluchenko has found a new type of Period 4 Oscillator which can be used in both wicks and agars. The first line of the illustration shows the first four orders of the wick version, with the last entry showing some alternate ends and sides. The use of Hats [9.1] also allows variable spacing and in some cases for sparks to appear between them. The second line shows how to bound the ends to create agars.