Hello , I read recently that the calculated the approx. amount of stars in the known universe to be 7x10^22, which is according to source, greater than the number of grains of sand in all the deserts and beaches on earth. Well, this is quite big, but as I was explaining this to some people around me, is there a known value of the number of grains of sand in let's say 1 cubic meter of sand ? I know some are very small and others are bigger : does someone has an approximate value ? I tried to find without success and also I have no idea on how to calculate this simple value. Thanks for any answer(!). source : a certain australian study : http://en.wikipedia.org/wiki/Observable_universe best regards and have a nice evening. Simon Plouffe