Pure Glider Reactions

There are many ways of colliding two gliders so both vanish:
2-glider vanishing reactions

These vanishing reactions can be used as sparks for other reactions, or to form glider logic circuits. There are also several ways of colliding two gliders so that only one glider results:

glider kickback reactions

These reactions can be used to position gliders for another reaction, to synchronize glider logic streams, or to nondestructively test for the presence of a glider. The reactions in which two head-on gliders produce a sideways glider should be especially useful in building glider salvos by setting up pairs of guns on opposite sides of the salvo track; this reaction is also used in my delay line construction.

Less useful curiosities are reactions in which two head-on gliders turn into two sideways gliders, and in which four gliders become six or six become eight. (However the first reaction could be used for duplicating glider streams, and the second forms the basis of the p216 gun.)

glider double bounce four gliders in, six out
six gliders in, eight out

B35/S236 -- Cellular Automata -- D. Eppstein -- UCI Inf. & Comp. Sci.