In article ,
Rodney Blackall wrote:
In article .com,
wrote:

I said nothing that Stefan Boltzman is wrong, dishonest little prick.
This is the same means you do science. Twisting the truth for the
effect you enjoy more. It is grenhouse theory which does not respect
Boltzman Stefan. This equation specifies a quantity of energy that
passes through the plane of a sq centimeter in 1 sec. Your use of this
in a simple means of denoting and influx of energy to area of
radiative area is absolutely false.

I thought Stephan Boltzman (and most other e-m radiation laws) relate to
"black bodies". I have not learned of ANY gases that act as black bodies.

kdthrge is a kook well-known to sci.environment, to which this thread had
been cross-posted.

Stefan-Boltzmann is indeed for black bodies, which the earth's atmosphere
is not. If one were extreme about the definition of black body, nothing
real is a black body. But for practical purposes, many natural things are,
including the solid and liquid surface of the earth. (Ok, maybe grey body,
but with a coefficient like 0.97 applied to the original Stefan-Boltzmann
law.)

But, to similar degree as earth's surfaces, it is possible for a sufficiently
dense, and preferably ionized, gas to act like a black body. This is the
case for the sun, which can be more or less well approximated by a black
body at, iirc, 5760 K. (Obviously you stay away from the Lyman-alpha part
of the spectrum in doing this.)

--
Robert Grumbine http://www.radix.net/~bobg/ Science faqs and amateur activities notes and links.
Sagredo (Galileo Galilei) "You present these recondite matters with too much
evidence and ease; this great facility makes them less appreciated than they
would be had they been presented in a more abstruse manner." Two New Sciences

Robert Grumbine wrote:

In article ,
Rodney Blackall wrote:
In article .com,
wrote:

I said nothing that Stefan Boltzman is wrong, dishonest little
prick. This is the same means you do science. Twisting the truth for
the effect you enjoy more. It is grenhouse theory which does not
respect Boltzman Stefan. This equation specifies a quantity of
energy that passes through the plane of a sq centimeter in 1 sec.
Your use of this in a simple means of denoting and influx of energy
to area of radiative area is absolutely false.

I thought Stephan Boltzman (and most other e-m radiation laws) relate
to "black bodies". I have not learned of ANY gases that act as black
bodies.

kdthrge is a kook well-known to sci.environment, to which this
thread had
been cross-posted.

Stefan-Boltzmann is indeed for black bodies, which the earth's
atmosphere
is not. If one were extreme about the definition of black body,
nothing real is a black body. But for practical purposes, many
natural things are, including the solid and liquid surface of the
earth. (Ok, maybe grey body, but with a coefficient like 0.97 applied
to the original Stefan-Boltzmann law.)

But, to similar degree as earth's surfaces, it is possible for a
sufficiently
dense, and preferably ionized, gas to act like a black body. This is
the case for the sun, which can be more or less well approximated by a
black body at, iirc, 5760 K. (Obviously you stay away from the
Lyman-alpha part of the spectrum in doing this.)


But you can use the same principles to model the downwelling longwave
radiative flux from the atmosphere to the surface. I think, but may be
confused by Deatherage at this point, he is arguing that radiative
transfer in general is wrong. He is also arguing that I am a pinhead, but
that's really a side issue.

The atmosphere is not a blackbody, but its radiative properties can be
modeled, and the net downwelling radiation from it is fairly accurately
known.

--
Bill Asher

In article ,
William Asher wrote:
Robert Grumbine wrote:

In article ,
Rodney Blackall wrote:
In article .com,
wrote:

I said nothing that Stefan Boltzman is wrong, dishonest little
prick. This is the same means you do science. Twisting the truth for
the effect you enjoy more. It is grenhouse theory which does not
respect Boltzman Stefan. This equation specifies a quantity of
energy that passes through the plane of a sq centimeter in 1 sec.
Your use of this in a simple means of denoting and influx of energy
to area of radiative area is absolutely false.

I thought Stephan Boltzman (and most other e-m radiation laws) relate
to "black bodies". I have not learned of ANY gases that act as black
bodies.

kdthrge is a kook well-known to sci.environment, to which this
thread had
been cross-posted.

Stefan-Boltzmann is indeed for black bodies, which the earth's
atmosphere
is not. If one were extreme about the definition of black body,
nothing real is a black body. But for practical purposes, many
natural things are, including the solid and liquid surface of the
earth. (Ok, maybe grey body, but with a coefficient like 0.97 applied
to the original Stefan-Boltzmann law.)

But, to similar degree as earth's surfaces, it is possible for a
sufficiently
dense, and preferably ionized, gas to act like a black body. This is
the case for the sun, which can be more or less well approximated by a
black body at, iirc, 5760 K. (Obviously you stay away from the
Lyman-alpha part of the spectrum in doing this.)

But you can use the same principles to model the downwelling longwave
radiative flux from the atmosphere to the surface. I think, but may be
confused by Deatherage at this point, he is arguing that radiative
transfer in general is wrong. He is also arguing that I am a pinhead, but
that's really a side issue.

The atmosphere is not a blackbody, but its radiative properties can be
modeled, and the net downwelling radiation from it is fairly accurately
known.

Certainly we can observe the downwelling radiation. Total integrated
values can be done pretty accurately. Spectral values aren't as
accurate, but pretty good (depending on what you're trying to do,
of course).

The emission of radiation by the earth's atmosphere, as for absorption,
is very non-black -- dominated by lines of absorption/emission (per
Kirchoff's law, these are the same place and strength). So CO2,
for instance, may be kicked to an excited state by collision with
something else, and then radiate energy from the appropriate excited
line. Or it can absorb radiation emitted by the surface and enter
and excited state, then either emit energy, or transfer it to some
other molecule in collision. Dress this up with the appropriate
quantum mechanics, and you can do the rigorous calculations as done
in, say, HITRAN http://cfa-www.harvard.edu/HITRAN/

While not blackbody, the thermodynamics involved in constructing
black bodies also tell us about this sort of process.

--
Robert Grumbine http://www.radix.net/~bobg/ Science faqs and amateur activities notes and links.
Sagredo (Galileo Galilei) "You present these recondite matters with too much
evidence and ease; this great facility makes them less appreciated than they
would be had they been presented in a more abstruse manner." Two New Sciences