Life Constellations

Size in bits: 6 | 8 | 9 | 10 | 12 | 15 | 16 | 17 | 18 | 20 | 24 | Larger
Cost in gliders: 2 | 3 | 4 | 6



There are an infinite number of constellations of each size (e.g. any two objects can be placed in a field with an arbitrary spatial offset between them), so only a small number of common, easily-constructed, and naturally-occurring constellations are shown. A few additional highly artificial ones are also included that have special functions (eaters, reflectors, etc.).

Some constellations produced by methuselahs are shown if they are small, and don't include gliders or other spaceships. A few small exceptions including a glider and one other small object are also included.



2 easily-constructible six-bit constellations

All arrangements of a two blinkers can be made from 4 gliders. There are many of these that can also be made from 3 gliders.

6b constellations

Two blinkers offset (4, 0) [3] Half traffic light [3]


2 easily-constructible eight-bit constellations

All arrangements of a boat and a blinker or two blocks can be made from 4 gliders, all arrangements of a tub and a block can be made from 5 gliders, and all arrangements of two tubs can be made from 6 gliders. There are many of these that can also be made from fewer gliders.

8b constellations

Two blocks offset (4, 1) [2] Two tubs offset (4, 0) [4]

Two blocks offset (4, 1) can eat a LWSS


2 easily-constructible nine-bit constellations

9b constellations

3/4 traffic light [3] Block and glider (via Wing) [3]


3 easily-constructible ten-bit constellations

10b const

Two point- to- point boats [3] Two boats pointing in opposite direct- ions [4] Loaf and blinker [2]


6 easily-constructible twelve-bit constellations

12-bit constellations

Killer toads [6] Traffic light [2] Eater-5 [6] Half honey- farm [3] Tear- drop [2] Butterfly [3]

Eater-5 is an eater that can eat gliders, but unlike Eater-1, that sits right in the middle of the glider's path, Eater-5 sits off to the side, making it more useful for picking off gliders from one stream that is very close to another, with an offset of as few as 9 cells. The less obtrusive Eater-5 is slightly larger and more expensive, but can also pick off gliders from one stream 8 cells away from another.

Traffic light predecessors are some of the most versatile objects in Life. Mangling them in many ways produces more of the same. Two of them together along an even line of symmetry form a Pentadecathlon, whose phase can often be altered, (for example, to period 9 or 54).

Even more interesting are two traffic light predecessors along an odd line of symmetry. In 15 generations, they split into two identical copies of themselves, eventually resulting in a Pulsar. However, if one of these two copies is removed, an oscillator results. Furthermore, if one of the blinkers is eaten from the side at the same time, the traffic lights reform one generation earlier. This yields simple oscillators of periods 28, 29, and 30. Pulsar predecessors can also be hassled in many other ways to produce other periods, such as 10 and 55.

If the half-pulsar is always eaten from the same side (which can be done by a c/5 spaceship), the pulsar predecessor becomes a spaceship push-along. Unfortunately, no way is currently known for this mechanism to work on its own without an external spaceship to push it along.

If traffic light predecessors (or 2 or 4, as in pulsar predecessors) are inducted on on all four sides, they produce a whole series of period 2 oscillators called Scrubbers.

Finally, two traffic lights can interact to push each other apart in 25 generations, leading to natural oscillators called Traffic Jams, of which a period 50 example is shown.


1 easily-constructible fifteen-bit constellation

20b const.

Blinker and 3 blocks (via Bookend) [3]


2 easily-constructible sixteen-bit constellations

16-bit constellations

Four skewed blocks [2] Blockade (via Lumps of muck) [2]


2 easily-constructible seventeen-bit constellations

17b const.

Less obtrusive eater-5 [12] Traffic light and glider [2]

Eater-5 is an eater that can eat gliders, but unlike Eater-1, that sits right in the middle of the glider's path, Eater-5 sits off to the side, making it more useful for picking off gliders from one stream that is very close to another, with an offset of as few as 9 cells. The less obtrusive Eater-5 is slightly larger and more expensive, but can also pick off gliders from one stream 8 cells away from another.


4 easily-constructible eighteen-bit constellations

18-bit constellations

3/4 honey- farm [3] Interchange [2] Loaf and tub and block and blinker [2] 3 Blocks and 2 blinkers (via Dove) [3]


1 easily-constructible twenty-bit constellation

20b const.

Ship two blocks and two blinkers [3]


4 easily-constructible 24-bit constellations

larger constellations

Small fleet [6] Fleet [3] Small honeyfarm [6] Honeyfarm [2]


18 easily-constructible constellations 26 bits and larger

larger constellations

Bakery [3] B1 eater [22] Pi reflector [46] Eater-3 [72] Variant eater-3 [42] 4 Beehives, 2 boats, 2 blinkers (via Thunderbird) [4]
Laundro- mat; 8 tubs [6] Bi-bakery [4] Century eater constellation [9] Snark reflector [48]
Killer candel- frobras [12-16] Two pulsars offset (16, 0) [4] (Two glider) Octomino: 2 Traffic lights, 4 beehives [2]
Two pulsars offset (17, 0) [4] Two pulsars offset (16, 2) [4]
P8 glider reflector [11] P15 glider reflector [20] Two bowties and two half traffic lights [4]

Eater-3 is an eater that can eat gliders, but unlike Eater-1, it can also eat many other things that grow at a corner. It consists of a catalyst still-life and a loaf. The loaf eats the target and flips over, then takes a bite out of the catalyst still-life (that reforms), and flips back. With appropriate pairs of sparks, it can also reflect pairs of gliders, allowing the construction of glider-loop oscillators of periods 18+8n.

The variant eater-3 is very similar, and much cheaper to construct. Unfortunately, it cannot be used to reflect glider pairs.

Bellman One (B1) is a specific eater found using Mike Playle's Bellman search program. (Actually, the name refers to the mechanism, rather than the form; the forms shown are the smallest currently known). It consists of a still-life and an eater, and is specifically designed to eat traffic-lights. A slight variant of it eats gliders instead.

The Century eater is specifically designed to eat a century.

Pairs of candelfrobras, known as "killer candelfrobras", can also eat expanding objects like middle-weight and heavy-weight spaceships, and forming 3/4 traffic light. These are most useful for eating spaceship streams whose period is a multiple of 3. For those whose period is a multiple of 2, Killer toads are more appropriate.

The Snark is a remarkable eater discovered by Mike Playle in April of 2013 using his Bellman search program. (Actually, the name refers to the mechanism, rather than the form; the forms shown are the smallest currently known). It has many remarkable eating properties. When combined with two eaters and a block, it forms a stable glider reflector that can reflect gliders 90 degrees as long as they are at least 43 generations apart. This allows for creation of glider-loop oscillators of every period 43 and higher, and is the first period 43 oscillator ever found. This is also the smallest (and fastest) stable glider reflector currently known.



The 11 small constellations buildable from 2 gliders

2-glider constellations

Two blocks offset (4, 1) [2] Teardrop [2] Four skewed blocks [2] Honey- farm [2] Blockade (via Lumps of muck) [2] (Two glider) Octomino: 2 Traffic lights, 4 beehives [2]
Traffic light and glider [2] Loaf and blinker [2] Traffic light [2] Inter- change [2] Loaf and tub and block and blinker [2]

Two blocks offset (4, 1) can eat a LWSS


13 small constellations buildable from 3 gliders

There are an infinite number of 3-glider constellations; these are some of the most common.

3-glider constellations

Two point- to- point boats [3] Half honey- farm [3] Butterfly [3] 3/4 honey- farm [3] Fleet [3] Bakery [3] Block and glider (via Wing) [3]
Two blinkers offset (4, 0) [3] Half traffic light [3] Blinker and 3 blocks (via Bookend) [3] Ship and two blocks and two blinkers [3] 3 Blocks and 2 blinkers (via Dove) [3]
3/4 traffic light [3]  


8 small constellations buildable from 4 gliders

There are an infinite number of 4-glider constellations; these are some of the most common.

4-glider constellations

Two tubs offset (4, 0) [4] Two bowties and two half traffic lights [4] Two pulsars offset (16, 0) [4]
Two boats pointing in opposite directions [4] 4 Beehives, 2 boats, 2 blinkers (via Thunderbird) Two pulsars offset (17, 0) [4]
Bi-bakery [4] Two pulsars offset (16, 2) [4]


5 small constellations buildable from 6 gliders

There are an infinite number of 6-glider constellations; these are some of the most common.

6-glider constellations

Killer toads [6] Eater-5 [6] Small fleet [6] Small honey- farm [6] Laundromat [6]



Related: constellations in multi-color Life.

Other types: still-lifes, pseudo-still-lifes, oscillators, pseudo-oscillators, oscillators by period, pseudo-oscillators by period, guns, multi-colored Life, basic spaceships and pseudo-spaceships, exotic spaceships, spaceships flotillae, puffers, constellations, methuselahs, not quite stable objects.

See also: Life objects sorted by: counts, frequency of occurrence, cost in gliders, name, size in bits, or type.

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This page was last updated on 2015-02-19.