I have reasoned that if i go by the assumption that i am here and the universe is as it is, the only things i can really understand are gravity, time and the study of nature (feel free to disagree) What happens at the time of death will be a topic for debate long after i have reached that point so i'm not even going to bother with that one. However water is an interesting one!! Please feel free to correct me but the way i understand how water came to be on this planet is that when the earth was cooling down water vapour was released from rocks, and the rest of the water we have must have presumably been delivered via an extra terrestrial source like comets and what nots?? Now i have read in numerous places that there is roughly 326 million trillion gallons of water on the planet. Has there been any studies into how much water vapour could have been released? Though i know those kinds of calculations are way above my head, they must be possible. I would like to find out the total amount of water we had before the bombardment for space...any thoughts??