We are told that at the centre of a black hole lies a singularity; very small and very heavy. We here a lot about the mass but not the size (diameter) of this object,I asume this is not zero So, incredibly tiny though it may be , it would still bel greater than 0. Questions;- What then is the size of a singularity?. Does it , or could it, vary according to the age and mass of the black hole? Could the singularity be continually shrinking, ie getting denser with time.It would only get to 0, of course, after an infinitely long time, ie, never.