:**vacuum** Empty space. That is, space containing only dead cells.

:**Venetian blinds** The p2 agar obtained by using the pattern `O..O` to
tile the plane.

:**very long house** The following induction coil.

.OOOOO. O..O..O OO...OO

:**volatility** The volatility of an oscillator is the size (in cells)
of its rotor divided by the sum of the sizes of its rotor and its
stator. In other words, it is the proportion of cells involved in
the oscillator which actually oscillate. For many periods there are
known oscillators with volatility 1, see for example Achim's p16,
figure-8, Kok's galaxy, mazing, pentadecathlon, phoenix,
relay, smiley and tumbler. The smallest period for which the
existence of such statorless oscillators is undecided is 3, although
Dean Hickerson showed in 1994 that there are p3 oscillators with
volatility arbitrarily close to 1 (as is the case for all but
finitely many periods, because of the possibility of feeding the
gliders from a true period *n* gun into an eater).

The term "volatility" is due to Robert Wainwright. See also strict volatility.

:**volcano** Any of a number of p5 oscillators which produce
sparks. See lightweight volcano, middleweight volcano
and heavyweight volcano.

:**V-pentomino** Conway's name for the following pentomino, a loaf
predecessor.

O.. O.. OOO