From: Amara Graps (agraps@amara.com)
Date: Tue Jan 07 2003 - 21:58:23 MST
Damien Broderick:
> During the past few million years, wispy filaments of interstellar gas have
> drifted into the Local Bubble. Our solar system is immersed in one of those
> filaments--the 'local fluff," a relatively cool (7000 K) cloud containing
> 0.1 atoms per cubic centimeter. By galactic standards, the local fluff is
> not very substantial. It has little effect on Earth because the solar wind
> and the Sun's magnetic field are able to hold the wispy cloud at bay.
A graphical representation:
P. Frisch's map of our Galactic Neighborhood
http://www.mpi-hd.mpg.de/dustgroup/dune/content/map.htm
ABlainey@aol.com:
>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?
The temperature refers to the kinetic energy of the ionized gas: the
plasma particles. This is a cool rarified plasma. It's not very 'hot'
in Universe standards.
7000 K -> (7000)(8.6E-5) ~.6eV
Conversion:
1 eV/k = 11604 Kelvin
(or k = 8.6173 x 10^-5 ev/Kelvin)
ev = electron volt
k = Boltzmann's constant
(note: 1 eV = 1.60217733 x 10-19 J)
For example, look here at our early magnetospheric 'bubble'
http://www.mpi-hd.mpg.de/dustgroup/~graps/earth/magnetosphere.html
Solar wind ~ 100 ev
magnetotail ~ 2000 ev
Geosynchronous orbit ~1000 ev
Plasmasphere ~.2ev
Some plasma introductions:
Plasmas - the Fourth State of Matter
fusedweb.pppl.gov/CPEP/Chart_Pages/ 5.Plasma4StateMatter.html
What are Plasmas
http://www.plasmas.org/rot-plasmas.htm
Amara Graps
(San Jose, Calif)
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