05-07-2003, 05:55 PM
And one note on helium, undissolved gases in water... they aren't defying gravity or anything. The medium that it is in is more dense, such as helium in air. It's easier to understand if you wanna put it in terms of weight. Air is heavier than helium... water is heavier than air. The air will fill up the lowest points on the planet, it is sinking to the surface of the planet (whether land or water). Then helium, hydrogen, the light gases are being pushed away from the surface, air is sinking under the helium and the helium molecules have no where to go but upwards. It will rise until it reaches an area of relatively equal density. Same thing is happening to the gas in the liquid in the tube of a level. Water is heavier than air... therefore as much as there is, it will fill the actual deepest parts.
Air gets less dense the further away from the planet it is, so less air higher in the atmosphere. At sea level, the pressure of air is at the maximum for that distance from the mass of the planet (that's why the speed of sound varies at different altitudes... the more dense the molecules are, the faster sound moves... also why temperature and moisture are factors). Argh... there's like several things I wanna say to make it all perfectly clear, but it's getting a bit hard to put into words. It's getting a bit off topic anyway, I just wanted to clarify a few things to avoid misconceptions.
Air gets less dense the further away from the planet it is, so less air higher in the atmosphere. At sea level, the pressure of air is at the maximum for that distance from the mass of the planet (that's why the speed of sound varies at different altitudes... the more dense the molecules are, the faster sound moves... also why temperature and moisture are factors). Argh... there's like several things I wanna say to make it all perfectly clear, but it's getting a bit hard to put into words. It's getting a bit off topic anyway, I just wanted to clarify a few things to avoid misconceptions.