Re: emergent behavior?

On Mon, 26 Mar 2007 12:04:55 -0400, r norman <r_s_norman@xxxxxxxxxxxx>

On 26 Mar 2007 08:36:14 -0700, "Robert Carnegie"
<rja.carnegie@xxxxxxxxxx> wrote:

On Mar 26, 2:26 pm, r norman <r_s_norman@xxxxxxxxxxxx> wrote:
On Mon, 26 Mar 2007 07:48:50 -0400, "George" <geo...@xxxxxxxxxxxxxxx>
"Anlatt the Builder" <tirh...@xxxxxxx> wrote in message
And "biology" isn't an energy source, finite or otherwise.

No? Aren't most hydrocarbons, in fact, biologically derived?

The seas of methane and ethane on Triton might indicate differently.

Jupiter's atmosphere is only 0.07% methane, but that is still an awful

The biggest fart in the known universe, but Shoemaker and Levy tried
to set light to it and it didn't take. Therefore not an energy

Obviously George had in mind terrestrial hydrocarbons. But were there
inorganic hydrocarbons on Earth originally, that got eaten or

And quite by the way, if anyone feels like investing actual effort in
presenting a realistic analysis of the contribution of evaporation of
hydrogen from the atmosphere towards resisting global warming /
climate change, I know someone who is curious. Evaporation cools,
doesn't it? This arises because I was reflecting that if there was
much hydrogen in the atmosphere, air would burn /here/. And we'd have
to be very careful.

For that matter, how much hydrogen /is/ lost? One source that I
looked at online had more to say about reacting with hydroxyl to form
water, and also absorption in soil, somehow or other. It didn't
mention it blowing off.

Things don't "burn" without oxygen. Also, burning is a chain
reaction where the heat produced by the oxidation of one molecule can
be used to raise the temperature of a nearby one enough to react. The
methane in our own atmosphere does not burn because it is far too
dilute to sustain such a chain.

The loss of hydrogen from our atmosphere is not evaporation, which
involves the change from a liquid to a gaseous state and does require
some heat input (substantial, in the case of water). It is produced
by the fact that Hydrogen is so light that thermal agitation causes
its velocity to exceed the gravitational escape velocity. It is
cooling to some extent because the higher velocity (hottest) molecules
preferentially escape producing a sort of Maxwell's demon situation.
However there are other so much more significant mechanisms at work
both heating and cooling the atmosphere that the effect is not
noticeable. There is a constant loss of hydrogen from earth into
space. Actually, there is a constant loss of all gases from earth
into space. It is just that Hydrogen is lost at a far higher rate
than the heavier gases.

The term "evaporation" is often used in cases where average kinetic
energy of a system is reduced by allowing mass to escape with it. This
works in near-zero-Kelvin cooling systems and stellar clusters, where
the average kinetic and potential energy of the individual stars is
reduced by allowing some to escape. Used in this way, no phase change
is required. Thus, it might be useful to speak of evaporative cooling
of an atmosphere by such an effect as H2 loss. Maybe.

During the earth's oxidation orders of magnitude more H2 was released
to space than is available now, but I have never seen a discussion of
its possible cooling effects.

John Vreeland (
"Will future ages believe that such stupid bigotry ever existed!" ---Ivanhoe