söndag 16 oktober 2011

Question to Curry about Stefan-Boltzmann and DLR

In a recent post Judy Curry lets Grant W Petty speak out with reference the ongoing discussion on my blog with Petty. Curry assists Petty with:
  • I will continue to (barely) follow Claes Johnson’s work to see if he is able to come with anything interesting or publishable.
Here is something interesting Judy of main importance to CO2 alarmism: In recent posts on Downwelling Longwave Radiation DLR and Stefan-Boltzmann's radiation law (SB) I have shown that CO2 alarmism is based on a version of SB without support in physics literature, a version I have referred to as False-SB, and I have compared False-SB with a correct version named True-SB.

Since you take up my work on your blog in critical terms, I think I have reason to ask you to articulate your critique of my work and in particular state if you consider False-SB to be true with a solid support in theoretical physics and experiment. Is it so? Or do consider my critique to be well founded?

7 kommentarer:

  1. You are trying to find differences where none exist. What you wish to call "False-SB" is mathematically identical to what you wish to call "True-SB". In every calculation you could ever make, in every equation you could ever solve, in every practical application conceivable, you would get the same answer whichever one you used because they are exactly the same.

    The relevance of your outpourings is not clear, because the atmosphere is not a black body, and it is certainly not treated as such in any modern climate calculations. If there's one thing that's clear from your numerous recent posts it's that your knowledge of physics in general and climate science in particular is woeful.

  2. Read my derivations of Planck's and Stefan-Boltzmann's laws, compare with your own and take the ones which make best sense.

  3. Another pointless non-response. Do you know how to have a discussion, Claes?

  4. What point do you want illuminated?

  5. Hi Claes.

    I've been making a point on both J Curry's site and WUWT that your deductions about the cut-off frequency provide the only plausible explanation of a mechanism which ensures that the Second Law of Thermodynamics works for radiation.

    Suppose a hotter body has much lower emissivity than a slightly cooler one. Then net radiative flux would be from the cooler one to the hotter one. So how is anyone going to show with SBL or whatever why the heat flow is from hot to cold? Only "Johnson's Law" (if I can call it that) provides the reason. All the radiation from the cooler one is merely scattered (if not already reflected) by the hotter one. So only the radiation from the hotter one has any effect on the cooler one of course. Heat "appears" to travel from hot to cold, though strictly it just appears at the receiving end because the energy in the radiation is converted there, rather like how we don't observe light until it hits something.

    Now, in a deeper vein, you may wish to consider what I postulate in this post: http://wattsupwiththat.com/2012/02/11/open-thread-weekend-7/#comment-892087

    I'd be interested in what you think.

    Finally, are you aware of the spectroscopy experiment (which I heard about but can't locate) which showed that a gas does not absorb emission from a cooler source, but does start to absorb when the source is warmed beyond its own temperature. This proves Johnson's Law at least for gases. Why not do it yourself and publish with attached reasons.

    Doug Cotton (Sydney)
    http://climate-change-theory.com (see Radiation page)

  6. "I've been making a point on both J Curry's site and WUWT that your deductions about the cut-off frequency provide the only plausible explanation of a mechanism which ensures that the Second Law of Thermodynamics works for radiation."

    If you think that there is no theory for a natural cut off, then my friend I advise you to take a look at condensed matter physics in general, and phonon theory in particular.

    Claes model is extremely simplistic and crude in comparison.

  7. Hi Doug: Yes I have been following your insightful comments. I agree with everything you say. Thanks for your valuable support to rational science.

    My analysis shows that heating will occur (i) if the incoming frequency is above the present cut-off freq of the absorber irrespective of the amplitude of the incoming wave (case of small emissivity of emitter of incoming wave or far away Sun), (ii) if the amplitude of the incoming wave is bigger than the corresponding amplitude of the outgoing radiation from the absorber at its present temp (case of chicken in micro-wave oven).

    Is it possible that a (black)body with high emissivity at low temp can heat a body with low emissivity at high temp? Not in my model of the interaction of two (black)bodies, because the bodies will have the same emissivity, and then the cold cannot heat the hot. In other models? I do not know for sure,
    and I have think more about this possibility:

    My analysis covers basically "quasi-stationary" states, which excludes heating from colder, but not all possible "startup" phases before "quasi-stationary", where the interaction between the bodies can be more complex.

    It is possible that in some start up phase a cold body of high emissivity can heat a hot body of low emissivity momentarily, but this seems far-fetched and of little interest. In "quasi-stationary" state the emission from the absorber has reached its maximal value for all frequencies below cut-off and all heating comes from frequencies above the present cut-off.

    Best regards, Claes