"First up, a common misconception in the climate debate is that radiation from a cold body (e.g. the -18C atmosphere) can warm a hot body (e.g. the +15C Earth surface) just because the cold body does indeed send very-low-energy photons to the hot body. Heat transfer (not radiation) from cold to hot is forbidden by the 2nd Law of Thermodynamics on a macro basis, and by the Pauli Exclusion Principle of fundamental quantum theory on an atomic and molecular basis.
If a lower-quantum-energy photon is "absorbed" by the completely saturated low-energy microstates (eg vibrational, translational, rotational, chemical bonds) & molecular or atomic orbitals of a higher-energy body, the hot body must simultaneously eject a photon of the exact same wavelength/frequency/energy as that absorbed, due to the Pauli Exclusion Principle of fundamental quantum theory. Thus there is no change whatsoever in the energy content/temperature of the hotter body due to "absorbing" a low-energy photon from the colder source with simultaneous emission of an identical photon of the exact same wavelength/frequency/energy (some instead refer to this as "reflection" of the lower-energy photon). This explains the 2nd Law of Thermodynamics on a quantum basis, thus why low frequency/energy photons from a cold emitter cannot warm a warmer blackbody at a higher frequency/temperature/energy.
Since the emitting temperature of ~15um photons from atmospheric CO2 is -80C by Wein's & Planck's Laws (also explained in the reference below), these photons cannot possibly be thermalized/increase the energy or temperature of the much warmer Earth surface at +15C."Many have asked why a photon with insufficient quantum energy cannot be thermalized or increase the heat energy of a warmer blackbody. This is the basis of blackbody radiation absorption and emission and Planck's Quantum Hypothesis, as is very well described beginning on page 146 of "Principles of Modern Chemistry, 7th Edition" excerpted below.
To falsely assume that a photon of any energy level can be thermalized by a blackbody at a given temperature would result in the dashed red and blue function in fig 4.8 below, which does not happen in nature. Therefore, Planck devised quantum theory to explain why blackbodies instead follow a Planck curve shown by the solid blue and red lines below (corresponding to different blackbody temperatures) and contain "cutoff frequencies for thermalization":
Word salad.
ReplyDeleteYet somehow the room temperature IR thermometer in my hand can receive photons from my freezer and measure the freezer temperature.
Magical.
I see. To you the chapter above is word salad. Well guess what, your IR thermometer measures heat loss from the thermistor to the freezer to measure objects colder than itself.
DeleteMagical.
I think diagram (fig 4.8 ) is misleading in one respect.
ReplyDeleteIt implies that the blue line emitter (7000K) with intensity maximum at 400nm cannot emit photons with wavelengths < 200nm
Perhaps the diagram has been oversimplified
Bryan
This makes perfect sense to me, but what still puzzles me is why you don't make a statement along the lines of "and this, children, is why the theory of the CO2 based greenhouse warming effect is false!" Isn't that what this is saying? That the theory that CO2 in the atmosphere is re-radiating long-wavelength IR that it has absorbed from the earth, as the earth radiates long long-wavelength IR, CANNOT BE TRUE. Do I have this right? If so, why the lack of fanfare?
ReplyDeleteCO2 does re-radiate IR from the surface both upward and downward, but the effective emitting temperature of CO2 photons is at -80C/15 microns. These low quantum energy photons have insufficient quantum energy to raise any of the already saturated quantum states in a warmer blackbody, either the atmosphere at -18C or the surface at 15C, and thus CO2 does not warm the surface. The gravito-thermal greenhouse effect is the one and only source of the troposphere temperature gradient or "greenhouse effect," but has nothing to do with CO2 levels. This has been known since Maxwell said so in 1872 & I'm simply pointing out things that have been known for a long time, which climate science has unfortunately ignored.
DeletePlanck's equation describes the theoretical energy hemispherical flux density of a black body in a vacuum. It does not apply to gases other than in an adjusted mathematical sense. The Stefan-Boltzmann equation similarly applies to SURFACES in a vacuum. Gases can absorb to some extent radiation in various wavelengths. Because gases are not surfaces the treatment must be on a volume basis. Beside the emissivity/absorptivity related to the wavelength over a particular temperature range (very small for CO2) it is necessary to consider a) the concentration -normally expressed as partial pressure (eg 400/1000000*50=0.02 kPa) and b) path length (eg 5000m) which at about 220K gives an emissivity factor of less than 0.007 which is a long way from a black body of 1.0. There is considerable doubt whether even this adjustment to the emissivity used in the S-B equation makes any sense in the atmosphere of a planet.
ReplyDeleteAs the Nobel prize winning Physicist W Lamb stated there is doubt whether photons exist. Even more so there is a doubt whether any molecule of gas radiates in all directions. Atoms on a surface (say a piece of metal) certainly do not radiate in all directions they only radiate (in a vacuum) away from the surface. One could consider squeezing molecules of gas to form a surface -they would then only radiate away from the surface to a colder environment.
I personally cringe when someone mentions photons. E-M radiation is emitted in waves of varying wavelength and which may have pulses There is no specific photon energy particle which has a specific frequency or wavelength. Think about it. There would then have to be an infinite type of photons.
"I personally cringe when someone mentions photons." Agreed.
DeleteWhy are there only photons for Light wave and IR range Electromagnetic Radiation? If for one must be for all, and some of the wavelengths of Electromagnetic Radiation would be near impossible (IMO). How would radio wavelength particles travel through space and then, upon impacting an antenna, be converted into an electric current? Keep in mind that the Military uses radio wave communications approaching sound-wave wave-lengths, 100Hz to 100kHz. And frequencies in this range are used to communicate with submarines deep under water. Seems near impossible if a "Particle." Then there is the problem of refraction and bending of light through solid mediums that only makes sense if a wave. The examples of "particles" of light causing a sort of paint-splatter build up effect, can be explained, in my mind, by the fact that they are doing it with VERY short bursts of light (1 - 10 wavelengths of the light) this could be just a false attribute of measurement and the wave canceling effect of these short wave lengths. - See the "particle impact" picture on https://en.wikipedia.org/wiki/Wave%E2%80%93particle_duality near the top of the article.
I am no Particle Physicist, or Quantum Physicist, but a Nuclear engineer and understand enough to have serious questions about the "Duality principal."
Just a bit more about Planck's equation. The constants and some variables in the equation are defined to be in a vacuum eg c the speed of light. The speed of light in a fluid (including gases) or transparent solid is less than the speed of light in a vacuum. In water over a short distance light is refracted proving the speed is reduced. Light is absorbed by water over some 100m. At a depth (distance) of over 100 m the speed or velocity becomes zero.
ReplyDeletePlanck in his book on radiation made the assumption that air was similar to a vacuum but this does not apply to an atmosphere that contains ozone, water vapor, CO2, particles and in particular clouds (of water drops, ice particles, H2SO4 etc). The supposed effect of "greenhouse" gases making the surface 33C hotter is nonsense because the S-B equation can not be used to make such a calculation.
Thanks cementafriend, very true "The supposed effect of "greenhouse" gases making the surface 33C hotter is nonsense because the S-B equation can not be used to make such a calculation."
DeleteYes and neither should GHGs be assumed to be blackbodies and to follow Planck's or Kirchhoff's laws. An interesting lecture on CO2 & H2O emissivity decreasing with temperature here:
http://hockeyschtick.blogspot.com/2014/05/new-paper-questions-basic-physics.html
I have read some of P-M Robitaille's papers and in the one you mention it is good to note the reference to Prof Hoyt Hottel the late Prof of chemical engineering at MIT. Re Kirchhoff's Law -yes it does refer to black bodies. The rider about Kirchoff's law about equality of absorption and emission in (good) texts on heat transfer (such as Hottel's in the Chemical Engineering handbook) is "in its surrounds" Absorption and emission are different if a source is at higher temperature than the body absorbing and then emitting radiation. eg the sun (at a theoretical 5500K) emits radiation peaking in the light range around 0.7 micron wavelength. Light can be absorbed by liquid water but water can not emit radiation at a shorter wavelength than a black body at 100C (373K). In fact nothing can radiate above its temperature. Another example heat a piece of steel -at around 900K you will see a dull red, at around 1250K you will see a yellow-orange and at 1500K+ there will be white light emitted. CO2 in the atmosphere at 220K can not emit radiation of around 10 micron (equivalent to the peak radiation of the earth at 288K) because a) the temperature is too low and b) CO2 does not absorb or emit at any temperature in this range.
DeleteThanks cementafriend. The most astonishing thing I recently discovered is that the "most influential climate paper of all time" by Manabe & Weatherald assumes that CO2 emits radiation as a blackbody would at emitting temperatures of up to 300K! In other words, they falsely assume it will somehow change its emission band from 15um to 9.6um peak emission from that of a 300K blackbody.
DeleteThermodynamics talks about the flow of heat i.e. large scale movement. Heat is a secondary, sensed quality of large groups of molecules.
ReplyDeleteThe radiative physics of CO2 says it can radiate infra-red energy in all directions but says nothing about it's effect on surrounding molecules.
When large amounts of CO2 radiate IR energy within the atmosphere, this will slow down the escape of heat from Earth to space. That's the Greenhouse Effect. Back-Radiation is just a calculation factor - not a real physical activity.
Too many people in Climate science muddle up the macro and micro effect.
Please note, some physicists have claimed to find in experiments that individual cool molecules have transferred heat to warmer molecules, while the total flow is always from warm to cool.
GHGs only slow down IR loss to space by a few milliseconds, easily reversed at night for no net heat gain.
DeleteThe real cause of the GHE is the gravito-thermal GHE, and the effect is IR emission from GHGs.
Ann, to some extent you are right but you do not correctly characterise engineers (who developed thermodynamics & heat transfer) and scientists. Prof Richard Feynman said (something like) "scientists make guesses for a hypotheses and theories, and then should test their hypotheses/theories by actual experiments. If an hypothesis can not be proved or falsified then it should be dropped". Engineers, however, work the other way. They carry out experiments, make (physical) models for testing, gather data from nature etc, They, then, analyse the data (eg dimensional analyses -Buckingham Pi theory, statistics, mathematical transforms etc) to form relationships which can become laws in time. Thermodynamics and heat transfer were in the past based on coarse measurements. Carnot (an engineer) developed an incomplete approach to the general law of conservation of energy some 300 years ago when instrumentation was rough compared with today and many materials were unknown. Engineers, today, do research with instruments and equipment such as lasers working at a sub-atomic level. It has been shown that the 2nd law of thermodynamics applies at an atomic level to achieve temperatures less than 1K. So-called "climate scientists " are incompetent in (Chemical, Electrical & Mechanical) engineering subjects and further many lie about their understanding.
Deletecementafriend, I didn't notice that I was describing scientists and engineers at all. If you want to be a bit pedantic then:- (a) engineers investigate by experimentation as a prelude to building something; whereas (b) scientists make guesses at how the universe actually works, then experiment to find flaws in the theory and improve on it.
DeleteIt has to be this way because the detailed quantum mechanics, particle physics, relativity, etc theories aren't perfect - getting there slowly, slowly.
Anne with due respect there is considerable doubt about quantum theory, the big bang, black holes, warping of space and time etc. However, one has to note the real achievements of engineers (from USA, Russia, China, & Europe) in putting satellites into orbit, landing persons on the moon, landing a space vehicle on the surface of Venus (Russians), putting the space station into orbit, landing a vehicle on Mars, landing a pod on a comet, and flying a space vehicle past Pluto. Engineers know the difference between an atmosphere and the near vacuum of space. They understand gravity. They know about time lags in communications, they know a lot about measurements and accuracy of measurements, they know that adjustments are necessary to make things work when theory is wrong etc etc.
Deletecementafriend, There's no disagreement between us that engineers have done amazing things in building and maintaining the satellites, space station and probes (particularly Voyager) which successfully handle and adjust to the forces of the universe including gravity and the slightly-chaotic orbits of the planets.
DeleteWe seem also to agree that physicists' attempts at producing a mathematical model of it all are a long way from being complete. Some of them think it's basically random - because probability theory was inserted into Quantum Mechanics & that gives results more like experiments than previous theories. Personally I think it's deterministic & mathematically chaotic. Rather like the climate.
Please see my comment today at Climate, Etc. once again debunking the anti-astrophysics and anti-HS troll named "ristvan" yet again, both in regard to his lies about the Volokin paper above and the Pauli Exclusion Principle, etc. as well:
ReplyDeletehttp://judithcurry.com/2015/09/04/week-in-review-science-edition-20/#comment-729691