Waterworld

Today in class we worked on Earth's atmosphere, weight of the air, temperatures and so on. After class I took my air conditioned siesta and enjoyed a pleasurable erection swimming in warm tropical seas with that girl in Waterworld (pic), when realized that something was wrong.

My Waterworld was IN THE FUTURE, but that was impossible, because EARTH'S FUTURE is Dryworld. Our atmosphere is a mix of gases, it is stratified according to the molecular weight of its constituents, with higher concentration of heavier molecules like nitrogen and oxygen near the Earth's surface and the lighter elements like Helium and Hydrogen floating somewhere up in the upper atmosphere, trying to escape Earth's gravity. Water is 18 g/mol while air average is 29 g/mol, so vapor must float and wander off into space. The difference in mol weights is so large that we must be leaking water all the time. Lets calculate how much water Earth loses per year and how much water must have been on Earth five billion years ago to arrive to the quantity of water we find today (1,386 million km3). Another question, at current rate of loss, when will Earth be waterless?

PS: You want to worry? I give you something to worry! The heaviest elements like Uranium and Plutonium gather near Earth's center of gravity, do they? Million tons of fissible material pressed together - what happens? A chain reaction is triggered and we have a mega nuclear reactor a.k.a. atom bomb. Do you want to sit on an atomic bomb? I dont. But have to. Could the sphere... explode? You bet! To make it worse, the ball nucleus is surrounded by spinning white-hot liquid iron. I dont like what is going on under my feet. Kind reader, let us move to some other place.