The problem with most skeptics is that they’re not good enough skeptics. They’ve done a good job and they’ve been a million times more rational than the alarmists – really no comparison here at all in rationality and intelligence level – but for some reason they’ve never gone for the kill and they’ve also adopted some of the silly pseudoscience of climate alarmism. I won’t share names but this email thread below is from a group of very well-known prominent skeptics:
SkepticA: “You do not understand radiation.
Ordinary heat transfer is a transfer of mechanical energy. All substances above absolute zero possess energy in the form of molecular motion and vibration. It is their energy that constitutes heat and its amount is measured by temperature. Mechanical energy can only be transferred from a substance with higher energy o one with lower energy. This fact is the basis of the second law of thermodynamics.
The energy of radiation is not mechanical . It is the result of alternating electrical and magnetic fields. It does not require a medium. Its energy is entirely determined by the temperature of the emitting object, and since every object has a temperature it is emitted from every substance above absolute zero. The energy depends on the fourth power of the absolute temperature of the emitting substance as derived by the Stefan Boltzmann radiation law.
Radiation energy is converted into ordinary heat when it is absorbed on any object or substance capable of it, regardless of the temperature of that substance. This process has nothing to do with the second law of thermodynamics.
It took a long time for scientists to understand the nature of radiation or indeed the mechanical nature of the other forms of heat transfer, so the old textbooks do not mention them.”
OK, firstly: “All substances above absolute zero possess energy in the form of molecular motion and vibration. It is their energy that constitutes heat and its amount is measured by temperature.”
Wrong wrong wrong! Thermal energy is not heat and neither heat nor energy is temperature! From Schroeder in “Thermal Physics”:
“Much of thermodynamics deals with three closely related concepts: temperature, energy, and heat. Much of students’ difficulty with thermodynamics comes from confusing these three concepts with each other.”
So right at the introductory level we have people on all sides who can neither define nor not further understand what energy, heat, and temperature actually are. I won’t define them for you right now but at least you have the textbook quote to cite that they are indeed not at all the same thing! This confusion about thermodynamic things is par for the course of climate alarmism, its bread and butter.
In any case, this was my reply to the argument:
JP: “I am sorry but this assertion “Radiation energy is converted into ordinary heat when it is absorbed on any object or substance capable of it, regardless of the temperature of that substance” is not true.
The transfer of heat and presence of heat flow for material objects is given by a 1st-order difference in temperature, typically looking something like Q = k(T2 – T1), with heat flowing from the warmer temperature T to the cooler one.
For radiation in a plane-parallel geometry similar to the material transfer scenario, the heat flow is Q = sigma*(T2^4 – T1^4), again with heat flowing from the warmer temperature T to the cooler one. That is the radiative law for heat flow and it does function precisely with the same limitations as mechanical transfer. If it didn’t, then you wouldn’t have this difference equation defining radiative heat flow where only the greater portion of energy from the warmer side relative to the cooler side can act as heat, exactly as with the mechanical case.
And with that, the radiative greenhouse effect of climate alarm is laid to rest as a false postulate, and climate alarm itself no longer has a basis in science.
One should consider that in either case – material heat transfer or radiant heat transfer – the fundamental force carrier of the heat energy is electromagnetism. In material transfer it is via “virtual” photons, and at a distance it is with “real” photons. In either case it is photons, and in both cases energy can only manifest as heat for that going from higher temperature to lower temperature.”
At this point another person on the chain joins in (unknown if skeptic or alarmist), and replies:
Although this may be splitting hairs,
- Your equations are correct.
- They imply that energy can be transferred from a colder body to a hotter body…
- But that net energy flow is always in the direction of hot to cold, in accordance with the 2nd
- And your equations do not invalidate the proposition that “Radiation energy is converted into ordinary heat when it is absorbed on any object or substance capable of it, regardless of the temperature of that substance”.
Regarding the latter.
A photon, regardless of source and of the temperatures, hits an absorbant molecule. What happens?
The molecule warms up – the energy of the photon is converted to vibration,
Subsequently the molecule may pass that energy on somewhere else, either by emission of a photon or by collisional transfer to another molecule. In the case of atmospheric gases, the latter is most likely – the chance of radiation of a photon before collisional transfer is minute, something like 10-9.”
This sort of response has been best characterized by a commentator here as:
“They seem to employ a pattern of agreeing with certain basics of JP’s thoughts and then trying to hold onto some vestige of the very idea that their conceded belief defeats — ambivalent to the point of confusing things even further, using such complexity of convoluted thought that ordinary humans have a hard time grasping what their error is. You need a PhD in math to understand the most advanced errors, it seems. And THIS is the advantage that some of these people seem to have. They have greater technical skills to create greater confusions that look great to people not steeped in enough math to know their maneuvers.” – RK
So, here was my email reply to “UnkownA” and their inverted, strange reasoning:
JP: “I am afraid that your position is duplicitous, and therefore incorrect.
You said: “net energy flow is always in the direction of hot to cold, in accordance with the 2nd law.”
This is what heat is. This is the definition of heat. Heat is what is needed to increase temperature as per the 1st Law of Thermodynamics. And it doesn’t transfer from cold to hot.
Therefore, when you said that indeed: “Radiation energy is converted into ordinary heat when it is absorbed on any object or substance capable of it, regardless of the temperature of that substance”, you are in a contradiction. You are contradicting the equation for radiant flow which you had just agreed with, and you are in contradiction to the definition of heat which you also provided.
Your scenario can help explain: “A photon, regardless of source and of the temperatures, hits an absorbant molecule. What happens?”
Firstly we can point out that you are simply assuming something about absorption and hence temperature increase requiring heat flow since this is the end point you seek, and this is also in contradiction to the things discussed above about defining heat flow, and so setting aside what you illogically intended: the answer is that heat flow and hence temperature increase depends upon the difference in source and receiver temperatures as per the definitions. If a photon doesn’t have the energy (i.e. frequency, since a photon’s energy is directly proportional to its frequency) required to cause an already-vibrating molecule to vibrate faster, i.e. it doesn’t have a greater frequency, then it cannot cause the faster-vibrating molecule to vibrate faster. You may know that temperature is proportional with the population of frequency components in the ensemble. Higher temperature means that both higher frequency energies are present and that there is greater population of energy across all frequencies. This is of course why heat only flows from hot to cold – because the cooler source cannot provide any additional energy frequencies that the warmer object doesn’t already have populated.
Heat transfers down a metal rod from the warm end to cool end, and the cooler molecules down the rod, down the gradient of heat flow and temperature, although they may be bumping against the molecules upward in the gradient, do not make the upward gradient of the rod become warmer. Although the molecules upward of the gradient “absorb” collisions with the cooler molecules down the gradient, the exchange is that the cooler molecules become warmer with heat flowing from hot to cool as the energy frequencies become populated down the gradient. The process here is electromagnetism, just up close. The same electromagnetism occurs at a distance and obeys the same limitations.
The material and radiant heat flow equations define that energy from the cooler, lower-frequency-population sources has no effect on the temperature of the warmer source. The warmer source raises the temperature of the cooler.”
Well that’s where things stand now, and I thought the true rationalists around here would like to see how things actually get on “on the inside”.
They don’t get on too well that is because this argument and these email chains have been done hundreds of times over now between our groups, and you can quite clearly see that the Slayer’s are the only ones around actually sticking to and utilizing the real definitions and hence the real physics of things. The other sides reply by re-stating their position, we reply by pointing out the errors and self-contradictions and contradictions to definitions. And again and again and again around it goes.
Eventually, everyone just hates the Slayers…hohoho.
“I think you will find that what Vincent said was basically correct.
The net heat flow by radiation is from hotter to cooler, but the actual heat flow from each source is sT^4 and this heat is received by the other body whatever its temperature.
Similarly, a body at room temperature is in equilibrium, receiving as much heat as it radiates.”
Isn’t that such a strange reply given what was already discussed? Here is my reply:
JP: For the reasons already discussed based on the definition of heat flow, etc., what Vincent said was not correct.
Heat is only the net portion of the energy difference. You are making the same mistake as Vincent by assuming that all energy is heat.
D: “the actual heat flow from each source is sT^4”
That’s incorrect. We reviewed the equation for heat and heat is the difference of that term with another. That term by itself is energy, and heat is the difference in energies between two sources.
From Schroeder in “Thermal Physics”: “Much of thermodynamics deals with three closely related concepts: temperature, energy, and heat. Much of students’ difficulty with thermodynamics comes from confusing these three concepts with each other.”
D: “Similarly, a body at room temperature is in equilibrium, receiving as much heat as it radiates.”
This is incorrect. Equilibrium is when heat flow is zero, when the difference in energy terms of the heat equation is zero because the terms are equal. The bodies are receiving equal amounts of energy, and heat is zero. For the radiant case you would have heat Q = s* (T1^4 – T2^4). Equilibrium is when Q = 0. That’s how thermal equilibrium is defined. If heat is zero in thermal equilibrium then there are no bodies receiving any heat at all. This is why it is so important to distinguish between energy, heat, and temperature.
You will not find sT^4 defined as heat in any thermal physics textbook. It is energy, only. And it is only the difference of two terms of these from two sources which is heat.
It’s just the strangest thing. You go over the definitions and show how their reasoning was incorrect…and then they simply repeat themselves over again. It’s so funny and ridiculous! lol
“You are purely arguing about semantics.
OK Everyone knows that radiant heat is actually electromagnetic energy.
Heat is just another form of energy.
So, what I was saying was that an object at room temperature receiving as much radiant energy as it loses is in equilibrium and therefore there is no heat flow.”
“I looked up the definition of semantics.
Semantics: noun, (used with a singular verb)
- Linguistics. The study of meaning. The study of linguistic development by classifying and examining changes in meaning and form.
- Also called significs. The branch of semiotics dealing with the relations between signs and what they denote.
- The meaning, or an interpretation of the meaning, of a word, sign, sentence, etc.:
We’re discussing nature and the way its physics works, and it seems to me that nature doesn’t behave half one way plus another, but quite precisely according to physics and hence mathematics. There is nothing more precise than the behaviour of nature and mathematics and therefore there is nothing more important than their semantics. So, “purely arguing about semantics” is precisely what we’re supposed to do with physics, because this is what gives us understanding of anything about it in the first place.
D: “So, what I was saying was that an object at room temperature receiving as much radiant energy as it loses is in equilibrium and therefore there is no heat flow.”
And that is a precisely correct statement! And it makes a difference, because if we forget the semantics like the alarmists do and incorrectly think that all radiant energy is heat, then one can mistakenly conclude that radiation from a cool source will cause a warmer object to become warmer still, just as Vincent did and as the alarmists do in their radiative greenhouse effect at the basis of their alarmism. This is the fundamental distinction which debunks the entire enterprise of climate alarmism, and so the semantics here are crucial, as goes the physics and mathematics.”
Does a gas warm when it absorbs photons?
I agree that electron orbits are the initial responders and that dropping back a level results in a photon. But that is not the whole story. If an atom in a molecule receives a photon and the electron is excited, does that change the vibration mode of the molecule? And if the molecule is involved in a collision before the electron slips back to its original orbit (as it will be in the vast majority of cases), will the energy be transferred as momentum to the colliding molecule?
It seems that is the case: gases warm when irradiated. And gas mixtures such as the atmosphere also warm. I have attached the very good (but not error free) paper by John Nicol.
Energy is Transmitted in Both Directions From Two Black Bodies of Different Temperatures
Your equation Q = sigma*(T2^4 – T1^4) says it most elegantly.
The net energy transfer, Q, is the difference of the energy transmitted from hot to cold (sigma T2^4) and the energy transmitted from cold to hot(sigma T1^4).
And note well, in this case the hotter body loses less energy (remains hotter) than if it were radiating to a void. Due to the energy it is receiving from the colder body.
Indeed a gas can be warmed by thermal radiation absorbed from a warmer source, and the presence of an atmosphere can keep the ground surface warmer. Neither of these are the radiative greenhouse effect though.
In the Nicol paper at equation 26 he writes an equation for demonstrating a radiative greenhouse effect (RGHE). The equation is wrong and nonsensical. This can be proven by removing “Io” from the equation 26:
esT^4 = Io + pesT^4
If we remove the solar radiation “Io” (night-time) then we have:
esT^4 = pesT^4
where p has already been defined in the paper as < 1. The premise of the equation is that the surface temperature is defined by the solar input plus some “backradiation” from the atmosphere which is a fraction of the surface flux. The equation has a contradiction if we simply remove the solar input as if it were night-time, and so something is wrong with it.
Firstly, to calculate equilibrium temperatures we set heat flow equal to zero. Heat flow is defined as the net flow of energy between two objects. In radiative terms you have Q = F1 – F2 where F are the radiative fluxes from the two objects. What Nicol does, and what the radiative greenhouse effect does, is add in a third term to this equation, where the third term is actually a fraction of the cooler term.
We would normally have Q = esT^4 – Io in order to calculate the surface temperature T given an external input Io. Set Q = 0 for equilibrium and then calculate T. Two different objects and their fluxes. What Nicol does and the RGHE does is add back in a fraction of the surface’s own energy, to get Q = esT^4 – (Io + pesT^4). Then when you set Q = 0 you get Nicol’s equation 26, although Nicol didn’t demonstrate where it actually came from. If you just state it in the way that Nicol and the RGHE does, then you might think it makes sense, but it is important to know where such an equation actually originates, i.e. from the heat flow equation.
Heat is defined as the net energy flow between two objects. The pesT^4 term is a third distinct object, the atmosphere, being added in directly. That’s not consistent with the definition of heat flow, its equation, and the Laws of Thermodynamics where energy from the atmosphere could only transfer as heat to the surface and warm the surface if the atmosphere were warmer than the surface. With Nicol’s and the RGHE formulation, energy from the atmosphere is being added directly to the surface as heat irrespective of the temperature relationship between the surface and atmosphere, where it is that two-party relationship which determines if energy from the atmosphere can act as heat for the surface at all. To know if the atmosphere can send heat to the surface to increase its temperature we must consider that relationship in and of itself according to the definition of heat flow between two bodies. Using the established formulations we then have:
Q = esT^4 – pesT^4
for the heat flow between the surface and atmosphere. Given that p < 1, and that the atmosphere is cooler than the surface typically, the equation then means that heat flows from the surface to the atmosphere and therefore the atmosphere does not increase the temperature of the surface by radiative heat flow. Hence, the RGHE is incorrect, as is of course Nicol’s formulation of it.
I suggest reading Nikolov and Zeller (https://www.omicsonline.org/open-access/New-Insights-on-the-Physical-Nature-of-the-Atmospheric-Greenhouse-Effect-Deduced-from-an-Empirical-Planetary-Temperature-Model.pdf) for a correct description of how the presence of an atmosphere affects the temperature at the bottom of the atmosphere depending on the total atmospheric mass and planetary gravity. They still use the term “greenhouse effect”, which I disagree with since a real greenhouse functions by a distinct mechanism not related to radiation or gravity, etc., but nevertheless the radiative greenhouse effect upon which climate alarmism is based is refuted by that paper as well, as it has been here.