|View static image|
|Pattern type|| Reflector |
|Number of cells||85|
|Discovered by|| Tanner Jacobi|
|Year of discovery||2016|
P11 bumper is a periodic colour-preserving glider reflector with a minimum repeat time of 44 ticks. Unlike the p5 through p8 cases where Noam Elkies' domino-spark based bouncer reflectors are available, no small period-22 colour-changing reflector is known. A stable Snark reflector can be substituted for any bumper. This changes the timing of the output glider, which can be useful for rephasing periodic glider streams.
A period 22 bumper can be constructed using 36P22, but the p11 variant is smaller in terms of bounding box and is compatible with all the same glider streams. In practice, even the p11 bumper is not useful with regular input streams below period 121, because lower-period bumpers can be used to reflect all smaller multiples of 11 for which the bumper reaction can be made to work.