We know the story; Noach builds an ark and thus survives the flood. (it's v interesting that they have found loads of archaelogical evidence as proof that this happened btw; from bones to cave scratchings, etc.) Anyway, just a small point; the flood lasts for 40 days. Why 40? the Maharal notes that 40 represents a new creation; thus, Moshe went up to har sinai to receive the Torah for 40 days - the giving of the Torah was a new creation in mankind. And there are 40 days fromRosh Chodesh Elul until end of Yom Kippur too; for that is supposed to be the time when we individually recreate ourselves and our lives.So too, when bringing a flood to the world that was to mark a new creation, 40 was the number of days it spanned.