Rodney Blackall writes:

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.

Don't expect that to convince kdthrge that he's wrong about anything.

Stefan-Boltzman is the result of integrating Planck's Law over all
wavelengths - the area under Planck's curve is total energy. If you
include emissivity in Planck's Law (perfectly reasonable), the resulting
integral is still total energy. If emissivity is constant with wavelength
(never really right, but not a bad approximation for most solids and
liquids over moderate ranges of wavelengths), then it just becomes another
constant in front of the Stefan-Boltzman equation, so you often see S-B
used with an emissivity term - a "bulk" emissivity.

...but to agree with you - gases dont' have emissivities that are
anything close to constant over any useful range of wavelengths, so using
an emissivity in a Stefan-Boltzman equation for a gas is a _very_ crude
approximation. It can still have its uses, but it has a lot more
limitations.