By definition, 5 is the natural number following 4 and preceding 6. It is also linked to a particularly popular Beethoven symphony, the last instalment of the Rocky series of films to be numerically titled and it is also the second Sierpinski numberof the first kind. Just ignore that last bit actually, we don't care about it either. What we do care about, and we're sure you will too, is that we'll be hosting the fifth edition of A Critical Mass on Saturday, January 30th at Ra