It is my great pleasure to provide for publication the following robust analysis and counter argument of former NASA scientist, Dr. Pierre Latour to Dr. Roy Spencer’s unscientific claims regarding the alleged heating properties of ‘back radiation.’ Latour’s detailed assessment affirms those aspects of Slayers’ science.
No Virginia, Cooler Objects Cannot Make Warmer Objects Even Warmer Still.
Pierre R Latour, PE, PhD Chemical Process Control Systems Engineer rebuts Dr. Roy Spencer’s article,’Yes, Virginia, Cooler Objects Can Make Warmer Objects Even Warmer Still’ (published July 23, 2010). [1.]
I have admired and learned from Roy Spencer's work on AGW & GHG for several years. He taught me a lot. He is well recognized in his field. Now I write to return the favor and teach him about the errors in his posting and how he can learn from my field. I read all 350 blog responses, and identify the correct ones at the end.
Spencer’s setup through paragraph 11 is OK, assume start is steady-state, all dT/dt = 0. Spencer does not say whether the chiller chamber surroundings at 0F are held there by constant heat removal rate (= plate power input rate) or constant T = 0 (adjusting power input rate). Spencer’s paragraph 12 claim that the radiating plate temperature will increase from 150 to 160F by absorbing some back-radiation from the inserted non-radiating 100 plate is merely a claim, without scientific theory or evidence to back it up.
His statement “This is because the second plate reduced the rate at which the first plate was losing energy.” is provably false. And the answer to his subsequent question in parentheses is: no. His statement “Again, the reason the heated plate became even hotter is that the second plate has, in effect, “insulated” the first plate from its cold surroundings, keeping it warmer than if the second plate was not there.” is not true.
If the claim were true, the total surroundings, including cooler plate, would receive more radiation from T difference = 160 – 150 = 10F and the chiller chamber temperature would increase to T > 0, even if the portion of surroundings blocked by the cool plate gets colder. The rest gets warmer. The chiller would have to remove more heat to maintain 0, but input electrical energy to the 150 plate is constant, so this requires creation of energy. The 100 plate does not insulate the 150 plate from all 0 surroundings.
The Stefan-Boltzmann law radiation law says radiation rate is proportional to its absolute temperature **4, no T difference involved; the radiation rate of 150 is proportional to its radiating T = (65.6 + 273)**4, no matter what the surroundings. However, the absorption rate of real bodies depends on whether the absorber T (radiating or not), is less than the intercepted radiation T, or not. If the receiver T > intercepted T, no absorption occurs; if the receiver T < intercepted T the absorption rate may be as great as proportional to (T intercepted – T absorber), depending on the amounts reflected, transmitted or scattered.
What actually happens is the chiller radiates to the hot plate, but the plate cannot absorb any of it because it is too cold. The hot plate reflects, transmits or scatters colder radiation, just like my roof does for cold radio waves. Insertion of the 100 plate blocks hot radiation to the portion of the surroundings behind it, cooling them to T < 0. But the 100 plate also radiates to the rest of the surroundings, heating it to T > 0. The combined effect is no change in radiation absorbed by total surroundings and average radiating temperature remains 0. The hot plate does indeed intersect 100F radiation from the cold plate, just as it intersects 0F radiation from the surroundings, but it cannot absorb any of it and warm since the incident radiation is too cold, < 150.
Examples are all around us. Chemical engineers design and operate radiant, convection and conduction furnaces, kilns, forges, chemical reactors and boilers for refining petroleum, manufacturing chemicals and generating electricity since 1920. We no longer need more experiments. No back-radiation is observed. Conducting this experiment will allow nature to tell which prediction is correct. This has been done already by
Prof Nasif Nahle, reported on 26Sep11 [2.].
Findings confirm the prediction T remains 150 is correct because a warm body cannot absorb cooler back-radiation.
An easy proof experiment is to park your car along a busy road at night with the headlights on. Move 5 meters in front and watch or measure your headlight emission brightness as approaching cars shine on them. Have you ever noticed your headlights getting brighter; then flickering back down as the oncoming car passes? No! Why? The hot bulb filaments do not absorb the low intensity, T, radiation from oncoming headlights, and reradiate it, brightening them.
to download PDF file to read FULL report from John O'Sullivan