Life Objects Without Known Syntheses

Still-lifes | P2 oscillators | P2 pseudo-oscillators | P3 oscillators | P4 oscillators | P8 oscillators 3-spaceship flotillae

Most small objects can be synthesized from gliders. Buckingham completed the monumental task of synthesizing all objects up to 14 bits in the 1980's.

Most still-lifes up to 14 bits, pseudo-still-lifes up to 15 bits, P2 oscillators and pseudo-oscillators up to 16 bits, and larger period oscillators and pseudo-oscillators up to 20 bits can also be synthesized. The basic Spaceships and pseudo-spaceships, as well as most flotillae of these can all be synthesized.

The few remaining objects with no known syntheses are shown here. Categories for which all syntheses are know are omitted. (NOTE: As technology improves, objects may be removed from these lists.)

0 still-lifes up to 14 bits without any known synthesis:

All still-lifes up to 14 bits can be synthesized.

(The syntheses of all 15-bit still-lifes are only about 25% complete, but all but about 100 appear to be buildable using previous techniques.)

The 66 period-2 oscillators up to 17 bits without any known synthesis:

At present, the technology for synthesis of oscillators containing large number of disconnected bits is sorely lacking.
unknown period-2 oscillators

The 8 period-2 pseudo-oscillators up to 18 bits without any known synthesis:

Mechanisms are known for adding all small period-2 oscillators except the bipole and tripole.
unknown period-2 pseudo-oscillators
Up cis bipole on bipole [x] Up trans bipole on bipole [x] Down cis bipole on bipole [x] Down trans bipole on bipole [x] Up cis bipole on tripole [x] Down cis bipole on tripole [x] Up cis tripole on tripole [x] Down cis tripole on tripole [x]

The 18 period-3 oscillators up to 20 bits without any known synthesis:

unknown period-3 oscillators
Candel- abra between two cis tubs [x] Candel- abra between cis and trans tubs [x] Candel- abra between trans tub and skewed pole [x] Candel- abra between cis tub and skewed pole [x] Cis skewed poles [x] Two pulsar quad- rants [x] French kiss [x] Trans skewed poles [x] TRIce- tongs siamese loaf [x] French kiss w/integral [x]
Candel- abra between cis up tub w/tail and cis tub [x] Candel- abra between cis down tub w/tail and cis tub [x] Candel- abra between cis up tub w/tail and trans tub [x] Candel- abra between cis down tub w/tail and trans tub [x] Candel- abra between trans up tub w/tail and cis tub [x] Candel- abra between trans down tub w/tail and cis tub [x] Snake below cuphook w/pre- block [x] Two back-to- back cuphooks w/pre- blocks [x]

The 9 period-4 oscillators up to 20 bits without any known synthesis:

Many of the larger mold-based oscillators are difficult to synthesize.
unknown period-4 oscillators
Mold tie hook w/tail [x] Mold siamese cis shilelagh w/hook [x] P4-20.1 [x] Mold siamese cis fuse w/two tails [x] Mold bit tie loaf [x]

The 3 period-8 oscillators up to 20 bits without any known synthesis:

unknown P8s
Coe's P8 [x] Smiley [x] Achim's P8 [x]

One three-spaceship flotilla (ignoring overweights) without any known synthesis:

There is no way known to add the rear spaceship in MWSS on MWSS #3, nor to add any of the Schick Ships to an existing ship or flotilla.
unknown 3-ss
Schick ship behind two MWSS on MWSS #3 [x]

Other costs: 2 gliders, 3 gliders, 4 gliders, >1 glider/bit, unknown.

See also: Life objects sorted by: counts, gliders, name, size, or type.

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