Re: a silly question


"Williamknowsbest" <William.Mook@xxxxxxxxx> wrote in message
news:cfb56ed0-de16-486c-9e6b-8d86af7ba9b4@xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx
Free hydrogen produced by certain microbes or by decomposition of
hydrocarbon deposits under certain conditions, typically reacts with
oxygen and other materials to form oxides, like water. Free gas that
makes it to the outer atmosphere escapes Earth altogether.

Here's the profile of temperatures with altitude
http://en.wikipedia.org/wiki/International_Standard_Atmosphere

Here's how molecular speed varies with temperature
http://en.wikipedia.org/wiki/Speed_of_sound

Why sound speed? Because that gives the AVERAGE speed of the
molecules. There is a normal distribution around the average speed.

http://en.wikipedia.org/wiki/Maxwell%E2%80%93Boltzmann_distribution

The molecular weight of hydrogen gas is 1/16th that of oxygen gas - so
sound speed is 4x higher for hydrogen than oxygen, and hydrogen
molecules travel 4x faster than oxygen molecules. So, if UV light
from the sun breaks down water into hydrogen and oxygen - the oxygen
moves around 0.3 km/sec and hydrogen 1.2 km/sec. The speed
distribution around those two averages is large for oxygen, small for
hydrogen. Even so, a vanishingly small amount of hydrogen escapes
from Earth - the tail end of the curve with hydrogen speeds exceeding
11 km/sec - drying the Earth ever so much and leaving spare oxygen in
its wake. Of course icy bodies fall to Earth at a constant rate which
balances this loss

Mars on the other hand, isn't so lucky! With an escape velocity of
5 km/sec and a graivty 1/3 that of Earth, rate of water loss is
exponentially higher (tail end of a distribution curve is nearly
exponential) and rate of replacement with icy bodies falling to mars
exponentially lower (ditto) - which means that the water isn't
replaced, and the spare oxygen 'rusts' the iron rich soil.

Wow,
sweet post.
Very informative.
Thanks
:)

--
James M Driscoll Jr
Spaceman






.

Relevant Pages

  • Re: a silly question
    ... makes it to the outer atmosphere escapes Earth altogether. ... molecules travel 4x faster than oxygen molecules. ... moves around 0.3 km/sec and hydrogen 1.2 km/sec. ... from Earth - the tail end of the curve with hydrogen speeds exceeding ...
    (sci.energy.hydrogen)
  • Re: Definition of "Mean High Water" on Ordnance Survey Maps
    ... water on a rising tide. ... shooting up the narrowing channel at a range of speeds, ... The moon, which causes the tide, performs a rotation around the earth once ...
    (alt.usage.english)
  • Re: More speed confusion
    ... That speeds transform according to the 'velocity addition formula' ... which does approximate 200 km/sec. ... The speed of the Earth around Sun is 30 km/sec, ... if you weigh two apples you get 1.9999997777778024691330589852157 ...
    (sci.physics.relativity)
  • Re: Twenty questions for creationists
    ... What are the three greatest challenges to evolution, ... earth was 100% tropical even in the polar regions. ... see today because a water vapor canopy encircled the earth much like we see ... The entire point of teaching both evolution and creation side by side would ...
    (talk.origins)
  • The Greening of Pseudoscience
    ... river of water, a great and spacious building; and it stood as it were in ... of God shall cover the whole earth. ... (Shared the 1965 Nobel Physics Prize with Feynman and Tomonaga) ... usefulness of quantum mechanics; this was one of the few limitations of this ...
    (talk.origins)
Loading