From: ABlainey@aol.com
Date: Tue Jan 07 2003 - 19:09:01 MST
Many thanks Robert, Now it makes a bit more sense.
Sincerely not so ignorant and confused anymore (well, about this anyway<G>)
Alex
In a message dated 08/01/03 01:58:44 GMT Standard Time, bradbury@aeiveos.com
writes:
>
> > Forgive my ignorance, But isn't 7000K pretty damn hot by our standard,
> That
> > being small squishy water based lifeforms. Or am I mistaken? I assume
> 7000k =
> > 7000kelvin or 6700 ish C, or does the K stand for another astronomical
> > measurement of temperature that I am not familiar with?
>
> It took me a long time to figure out what the astronomers meant by this.
> It turns out its a measure of the degree of ionization of the atoms floating
> around in space. It takes a lot of energy for example to strip of 5-9
> electrons
> from an iron atom (very high temps). If the electrons are pushed far enough
> away, they cannot be recaptured and the iron atom remains ionized. If the
> atom happens to bump into an atom with a lower temperature, its going to
> strip off its electrons, effectively leaving that atom at a higher
> temperature.
> And so it goes.
>
> > If I am right in my assumption, then wouldn't that kind of heat caused
> > problems for any out of solar system travel we have in the future?
>
> It depends on the density of the highly ionized (high temp) atoms.
> As Spike, Amara and I have previously discussed this varies a lot
> depending on where you are (in the local bubble, I think its like
> 0.001 atoms/cu cm). In high density regions if you are traveling
> at high velocity you do need an ablation shield to absorb the
> impacts of these ions.
>
> > or is the
> > relatively low density of heated atoms insufficient to cause significant
> > problems.
>
> In the bubbles it seems to be a minor annoyance -- but it depends in
> large part on how fast you are going.
>
> > Could the heat be collected and used as a power source for a vehicle?
> > I'm thinking something along the line of heat to laser light, bounced of a
> > light sail.
>
> I haven't run across that idea before -- I expect the conversion
> efficiencies and/or energy harvesting efficiencies would be pretty low.
>
> Robert
>
>
>
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