Some other sources: http://astronomy.swin.edu.au/~gmackie/billions.html http://everything2.com/title/There+are+more+stars+in+the+universe+than+grain s+of+sand+on+earth http://answers.google.com/answers/threadview/id/539329.html -----Message d'origine----- De : math-fun-bounces@mailman.xmission.com [mailto:math-fun-bounces@mailman.xmission.com] De la part de Simon Plouffe Envoyé : lundi 1 novembre 2010 18:01 À : math-fun Objet : [math-fun] a question of sand 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 _______________________________________________ math-fun mailing list math-fun@mailman.xmission.com http://mailman.xmission.com/cgi-bin/mailman/listinfo/math-fun