torsdag 16 maj 2013

Roy Spencer: "Back Radiation" is Real, But "Back Conduction" Is Not

Roy Spencer did not appreciate the following comment of mine to his post
A Simple Experiment to Show How Cool Objects Can Keep Warm Objects Warmer Still:
  • Roy, I am stunned by the “experiment” you plan to do: Everybody understands that the outside temperature affects the inside temperature of a house under constant inside heating. But it is an abuse of both physics and language to claim that a cold exterior is heating a warm inside, when the true physics is that the a warm inside is heating a cold exterior, that is that there is a uni-directional flow of heat energy from a warm inside to a cold outside, by conduction or radiation.
  • I cannot understand from where you get such a strong urge to twist physics and language by claiming that a cold outside is heating a warm inside by “back conduction” or “back radiation” through the space separating inside from outside. Why do you insist propagating false physics which violates the 2nd law?
More precisely, my question made Roy very angry:
  • Claes, you are the one abusing physics, and twisting my words. I never claimed that “a cold exterior is heating a warm inside”, only that it affects the temperature of the warm inside. Also, I never claimed there was such a thing as “back conduction”.
  • I *do* however claim that the atmosphere emits IR radiation in all directions, and if the atmosphere emits IR downward it must then affect the surface temperature.
  • Since you insist on twisting what I say, consider yourself banned along with the other Slayers I have banned.
And yes, my reply where I informed Roy that I am not a slayer, and in mild words repeated my question, did not show up on Roy's blog, and so I now repeat the question on my own blog, inviting Roy to comment: Why do you insist Roy that there is "back radiation" when you don't think there is any "back conduction"? What is the difference Roy?

PS1 If a question is met by an outburst of anger, the question may be a good one.

PS2 The idea put forward by Roy that "the atmosphere emits IR radiation in all directions...and it must then affect the surface temperature", is similar to phlogiston theory in the sense that some form of heat carrying particles (IR radiation/IR photons/phlogistons) are supposed to be emitted from the cold atmosphere, which "affect" the surface temperature by "keeping it warmer still".  What drives Roy into this kind of ideas is a mystery to me. Evidently, Roy does not believe that heat conduction is carried out by some form of heat carrying particles/phlogistons transferring heat energy back and forth between different bodies, but for some reason believes that this is so in radiative heat transfer.

4 kommentarer:

  1. Excellent question. This lies at the heart of the issue. Roy's explanation seems to be that photons, as opposed to phonons then presumably, do not stick out their fingers to measure the surrounding temperature.

  2. Dr. Roy Spencer joins Anthony Watts (of as another "lukewarmer" who has always reacted to those who deny the "greenhouse effect" with their own emotional denial of any possibility that the "basic science" is not settled, or is even wrong. All those who believe in the "greenhouse effect" know, deep down, that once they do that, they are lost, because the wealth of objective evidence would then quickly show that the presumed effect is in fact wrong--indeed it is incompetent physics. And that would mean they would have to admit they were wrong (and incompetent all this time), those who instructed them as students were wrong (and incompetent), and climate "science" has been a sham for a good two generations (basically, since the present radiative transfer theory, with its "blackbody" earth surface and atmospheric "backradiation", was accepted as the foundation of all atmospheric physics--and the showman Carl Sagan led all of science astray with the "runaway greenhouse effect"). The reality, of course, and as my Venus/Earth temperatures comparison so startlingly confirmed, is that what rules the atmosphere is the hydrostatic vertical temperature lapse rate structure, and the utterly stable, more than a century old, Standard Atmosphere model that is defined (in the troposphere) by that lapse rate--and even worse, that the almost universal belief among scientists, that the atmosphere is warmed, globally, by the heated planetary surface, is also wrong. My Venus/Earth comparison demonstrates the fact that heat from the surface has nothing to do with global mean temperature, at any level in the troposphere. No academic I know of, even you I think, wants to believe that, yet it is the simple, demonstrated fact of the Venus/Earth comparison.

    They are showing they cannot admit failure of their field, by their angry actions. But it HAS failed.

  3. I am surprised that yuo still are putting this subject up on the table. As you know the Kirchoff´s law of radiation together wirh the Planck´s law of radiation prooves that one warm and one cold body can exchange energy both ways. But the net energy of course will be from warm to cold.
    And Roy is of course right, that an atmosphere containing e.g water vapour, CO2 and other gases will affect the earth surface temperature. Do you really deny that. No, I don´t think so.

  4. It's all about potential. Like billard balls the energy of light is transferred from high to low, from higher frequency to lower frequency.
    Once a photon with energy higher than the excitement state of a certain electron hits this, the electron will get more excited. If a photon with energy lower or like the excitement state of the electron hits this electron, nothing happens.
    Since all matter reduces the energy of photons to lower frequencies (=energy) at re-radiating those re-radiated photons can never rise the excitement status of that matter again.

    The only way Roys idea of a certain insolation effect of back radiation could work is by preventing the matter from radiating IR light. He may think the more IR photons are around a material, the lower the radiation should be. As if the lower energy IR photons around a certain mass are making up a sort of pressure which prevents the exited electrons from firing off a IR photon.

    I think Roy Spencer is intelligent enough to not question the fact, that photons with lower energy cannot excite an electron further which is on a higher energy level than that IR photon.

    But to save his beloved theory of back radiation having any effect to reduce cooling he might cling to that idea that lower energy photons around a radiating mass might create sort of pressure that will prevent excited electrons from firing off photons.

    Electrons are jumping in quanta. They are oscillating in a defined excitement state and there's no state in between. The fact that there are a lot of electron orbits which all can be excited up to the state that an atom is stripped off its electrons completely provides a lot of different quanta and therefore a lot of different oscillating photons as a result of quantum leap downwards. But nevertheless it remains quantized.

    A photon with too low energy won't excite an electron. It won't add up its energy to shift the electron one quantum upwards. So it won't do anything to that electron. One might compare that to water. Flowing water has an eroding effekt, still water not.

    So a colder mass cannot, by no means, heat up a warmer mass.

    Insofar we and Roy Spencer probably agree.

    But the IR photons from back radiation are in fact real and they are there. Since in real life an equilibrium is rare, there are allways parts which cool faster than others (by means of convection and evaporation or laying in shadow etc.)

    Take a certain place in shadow, which cools by radiation, convection and evaporation. The back radiation will do nothing to warm regions but might re-warm faster cooling regions again which has cooled below the exciting energy of back radiation.

    But this might be the case in only a very small time frame during a day when the surface material is in lower excitement than the energy of the back radiating photons.

    These moments will be rare and short timed because of the ever moving air. So the summed up effect should indeed bee negletable.

    So the only idea for saving the back warming theory is the radiation prevention by IR photon pressure - an insolation effect.

    I don't know whether anyone has considered this idea in detail.

    Btw. the experiment Roy laid out includes some sort of device to protect convection. The polyproylene sheath he suggest will cause a tunnel effect and convection will be even stronger.

    Im keen on the results of his experiment (which should be done in a vacuum, anyway to provide reliable results).