Still life

A still life is any pattern that remains exactly the same from generation to generation--in other words, one in which every live cell has either two or three live neighbors and no dead cell has exactly three live neighbors. Empty space is generally not considered a still life.

Examples (using # to denote a live cell and a space to denote a dead cell):

A block, the most common still life:

## ##

Beehive (the second most common still life), loaf and pond, respectively:

#   ##    ##  #     #    ##

Tub, boat and ship (not to be confused with spaceship), respectively:

#  ##   ##  #    #    ##

These can be extended to form larger still lifes such as these:

# #   #   # #    # #    #      ##

Note that the extension on the right must have both "bent ends", though they do not have to face in the same direction.

There are infinitely many still lifes--these are just a few.