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Discussion > Where is Rhoda's Evidence? (plagiarised by Dung)

Dung, both your previous post relate to the idea of the vector of heat.

Firstly,

confirm that radiant energy flux is a vector that always flows from hotter to cooler objects

Yes, the flux flows from hotter to cooler objects, but because it is a vector, it can be made up of two or more separate energy flows which can operate in the opposite directions. So while it is true that the vector sum of the fluxes always flows from hotter to cooler, it is NOT true that the composite flows that comprise that vector sum have to, only that the one from the hot side to cool side is larger than the one from cool to hot, so that the vector sum of them always goes from hot to cool.

What this means in reality is a hot body cooling down will cool down more slowly if there is a cooler body near it, because the cooler body also radiates heat, a lot less than the hotter object, but that the vector sum of the hot body emitting heat and absorbing the much smaller amount of heat from the cooler object means (when summed) that it is cooling more slowly than it would without the cool object.

Some naïve readers interpret this as "a cold body cannot heat a warm body" - which is simplistically true, but it hides the fact that the existence of the cool body near the hot body does make it warmer than it might be if the cool body wasn't there, by slowing its natural cooling.

Your second point

If an action causes an effect and at the same time the effect causes a reaction which cancels the original effect, why would it not be appropriate to say that the original action has no effect or even that it does not exist.

It's a bit semantics this one. If you switch on your electric fire and open your window so that the temperature in the room neither goes up nor down, you cannot say that the fire's heat "does not exist". Of course it exists, but it is being offset by another thing which is also affecting room temperature.

Your more subtle point, I think, is that if the counter effect is caused by the original heat (e.g. a thermostat opens the window when it gets too hot) then should the combination of the effect and the counter-effect being zero, is it even worthwhile considering that the original effect exists, if it is smoothly counteracted automatically?

The answer to this is again semantics, and is determined by whether you are interested in mechanics or effects.
In effect, it does not exist or is small - which is the sceptical position - NOT that the constituent parts do not exist in reality.

Nov 13, 2015 at 6:48 PM | Unregistered CommenterTheBigYinJames

BYJ

With genuine respect, your explanation contradicts the statement by E Forster, he states;
"radiant energy flux is a vector that always flows from hotter to cooler objects".
This statement denies that there is a second vector from cold to warm i.e. no back radiation.

Nov 13, 2015 at 7:14 PM | Registered CommenterDung

Martin A

You are a hard master sir hehe.
OK warming in the sense that I have used it means: raising the average surface temperature of the planet ^.^

Nov 13, 2015 at 7:21 PM | Registered CommenterDung

Dung, I think you misunderstand that a vector is. A vector is a direction, which can be the addition of more than one component.

If you walk a vector of 1 step forward, and another vector of two steps backwards, then your sum is 1 backwards. But the 1 forward and the 2 backward exist as separate entities which are real and exist. The net effect is the vector sum of them, which is useful for calculating the mathematical final resting place, but which hides the actual vectors involved.

So what I said does not contradict E Forster. When you sum vectors, you get a vector, as in the above example. The corollary is that every vector can be expressed by the addition of two or more other vectors, but there is no way of knowing what those were (e.g. 99 steps forward, and 100 steps back would result in the same 'final' vector of 1 step back. As would 1 right then 1 back then 1 left. As would 3 back then 2 forward.. etc etc)

Therefore, when it comes to radiative transfer, saying a vector of energy flux always goes from hot to cold is the equivalent of saying that the sum of all the energy vectors results in a vector which flows from hot to cold. But like with the steps, this says nothing about which vectors you summed. Only that the result was from hot to cold. In reality you have a hot object radiating a lot and absorbing a small amount of the cooler body's radiation. Since one is always larger than the other, the sum of a large emitting vector and a small absorbing vector in the opposite direction will always be a large emitting vector - but importantly, not as large as the emitting vector if the colder body wasn't there.

In effect, the hot object emitting is you stepping forward 100 steps, and then subtracting the 1 step backwards absorbed from the cold object. The vector sum is a vector 99 steps forward. There is no way the small number of steps provided by the cold object could ever make you end up backwards from where you started. You're always going to be somewhere forward (100 minus 1 in this vector sum).

This is the same as saying the vector flux of energy is always going to go from hot to cold. But it hides the fact that a small part in the sum is actually in the opposite direction.

Does that help?

Nov 13, 2015 at 8:05 PM | Unregistered CommenterTheBigYinJames

A vector is not just a direction and in this case I think we are talking about a force with direction or an effect with direction (I am sure there is a better description). What you are talking about is the result of two vectors (one in each of two opposite directions) but in E Forster's statement there is only one vector (and I do remember vectors hehe).

Nov 13, 2015 at 8:22 PM | Registered CommenterDung

Martin A

Yes, the interior surface of the tube would need to be reflective, at least in the IR. As you note, if the tube were transparant or black the energy would dissipate into the walls. If the inner surface is reflective, the IR bounces back into the gas to be reradiated. The path length at troposphere pressures and concentrations is a few micrometres, so absorption/ reradiation will take place many times before escaping from either IR transparent end.

IIRC the same sort of tubing is used for CO2 lasers, and for the same reason. Indeed a CO2 laser works like the tube experiment, but with the windows replaced by one full and one partly silvered mirror.

Only at stratosphere pressures would the path length be sufficient for much of the IR to pass through unabsorbed.

Micky H Corbett is right that under normal troposphere conditions the mix of other gases and water vapour makes the interaction much more complex. The tube experiment is an attempt to isolate the effect of CO2 from the rest and demonstrate that the effect is concentration dependant.

Alarmist/denialist

alarmist
əˈlɑːmɪst/Submit
noun
1.
someone who exaggerates a danger and so causes needless worry or panic.
"the problem is a fabrication by alarmists"

denialist
dɪˈnʌɪ(ə)lɪst/
noun
a person who refuses to admit the truth of a concept or proposition that is supported by the majority of scientific or historical evidence.

Classifying people depends on the outcome and the evidence.

If the evidence I present is correct and CO2 driven climate change becomes a serious problem I am not an alarmist and dung is a denialist.

If the evidence is wrong and CO2 driven climate change does not become a serious problem I am an alarmist and dung is not a denialist.

Ultimately, since this will only become clear in retrospect, classification is probably moot.

Nov 13, 2015 at 9:45 PM | Unregistered CommenterEntropic man

Martin A

Your 6.36 comment makes the division between dung and myself very clear.

If the CO2 greenhouse effect is concentration dependant, then our industrial CO2 will amplify the GHE and the planet warms.

If the CO2 greenhouse effect is not concentration dependant, then our industrial CO2 will have no effect.

Nov 13, 2015 at 9:46 PM | Unregistered CommenterEntropic man

EM 9:46 - yes that makes it clear. Except of course for an intermediate position where there is an effect, but too small to be a nuisance.


_________________________________________________________________________________

Alarmist: someone who exaggerates a danger and so causes needless worry or panic. "the problem is a fabrication by alarmists"

That also makes it clear. So whether the term applies or not depends on your point of view.

If you think that the danger is very real and serious and that worry is justified, then you would not consider yourself an alarmist, even if you cause a lot of alarm all over the place.

But someone who thinks you are exaggerating the dangers, and that the worries caused are needless, could characterise you as an alarmist, although you would not agree with their characterisation.

From the definition you give,. I don't see that using the term is any worse than someone saying "I think you are exaggerating the dangers and causing needless alarm and panic".

Nov 13, 2015 at 10:39 PM | Unregistered CommenterMartin A

It does not really matter what EM or Martin A or I think, what matters is what happens in the real world and certainly since the days of Hansen all the warnings have been false. In addition recorded historical facts disprove Mann and others who claim the Medieval warm period to be fiction.
The Smithsonian Museum of Natural History tells us that during the Devonian period; atmospheric levels of CO2 fell for 100 million years and yet temperatures stayed high. Give me some real world evidence EM?

Nov 13, 2015 at 10:52 PM | Registered CommenterDung

Dung

You were talking earlier about vectors. You can think of a temperature change. as the vector sum of all the forcings and feedbacks which cause warming or cooling.

You mention that the Devonian stayed warm while CO2 decreased. Do you have information on what was happening to the other possible vectors?

Note also that the reduction in CO2 was probably due partly due to the development of a new carbon sink in the form of the first large land plants and exacerbated by a period of mountain building and rapid weathering.

Finally, the Devonian period ended with a cooling climate and a mass extinction.

I suspect that "climate stayed warm while CO2 dropped"' grossly oversimplified what actually happened.

Nov 13, 2015 at 11:51 PM | Unregistered CommenterEntropic man

You can think of a temperature change. as the vector sum of all the forcings and feedbacks which cause warming or cooling.

So you think those things are linearly additive?

Wouldn't it better to use the term 'vector sum' only for the sum of things that actually are vectors? A temperature change is not what most people would think of as a vector.

Nov 14, 2015 at 9:38 AM | Unregistered CommenterMartin A

Dung, once again I run up against the amazing impenetrable force of your misunderstanding. It truly is a thing to behold. A vector is a direction and a magnitude. In order to simplify it for you, I only considered unit vectors, so we could dispense with the magnitude. To then jump on that simplification as a fatal flaw in my argument is ingenious. Please consider why I thought it necessary to simplify it for you.

An energy flux is a vector in that it is both a direction and a magnitude. And being a vector it is not a measurement of the energy flows themselves, only the numerical sum of them. This is why when we see an energy flux diagram you get arrows in both directions, and the 'output' of such an analysis the imbalance, i.e. the arithmetic sum of all the vectors.

In the earth sun system, the two bodies are in balance, i.e. the solar flux of about 340 W/m^2 arrives at the earth, about 100 W/m^2 is immediately reflected, about 200 W/m is absorbed and re-emitted by the atmosphere back to space, and about 40 W/m^2 is directly emitted from the ground to space. These figures are approximate. As you can see, the incoming and outgoing flux add up to zero. This is because we're in thermal equilibrium with the sun, if we weren't we'd heat up or cool down

So the 'flux' between the earth and moon is 0. This does NOT mean there is no energy exchange. As you can see, there is a LOT of energy exchange, but because the vectors arithmetically cancel, the net vector sum is zero.

I realise this will bounce off your armour of intransigence, but there you go. Perhaps it will help someone else.

J.

Nov 14, 2015 at 10:10 AM | Unregistered CommenterTheBigYinJames

Dung

I am not sure what you mean by false. IIRC Hansen's 1984 prediction of a 1C rise between 1880 and 2010 was almost spot on.

Before we discuss the MWP, could you be clear about how you percieve the Mdeieval Warm Period. When did it start? When did it end? What were the global temperatures before, during and after?

A global instrumental temperature record is numerical real world evidence, readings from thermometers on land surface and measuring the temperature of seawater. You recently described these as "the (spurious, meaningless, fabricated) average temperature of the planet at the surface."

You concept of real world evidence is very different from mine. I cannot think of anything anybody could present as evidence, which you would accept.

Nov 14, 2015 at 11:41 AM | Unregistered CommenterEntropic man

Martin AA

Talking to dung of forcings and feedbacks would probably go over his head. If he understands vectors they may be used as an analogy.

My own mental image of energy flow and storage in the climate system is more like the MONIAC hydraulic model of the economy

Nov 14, 2015 at 11:54 AM | Unregistered CommenterEntropic man

Dung,
Everything radiates something.
Just because something is cooler than something next to it does not mean it stops radiating.
A vector of radiation flow is the net result of a dynamic relationship.
Think of the radiative process as temperature. If you put a frozen pizza in the oven it radiates its temp at 20.0 oF or whatever. The oven is 375 oF. The vector is the net of the two, which shows the pizza warming up and baking and the oven cooling down slightly as the pizza absorbs the heat from the oven. But the pizza still retains its discrete temperature. Which means it HAS to be radiating.

Nov 14, 2015 at 12:17 PM | Unregistered Commenterhunter

"forcings and feedbacks"

Concepts unknown to physics outside of climate science?

Nov 14, 2015 at 12:29 PM | Unregistered CommenterMartin A

First of all I am not an idiot ^.^
Secondly nobody seems to have read what I wrote hehe:

BYJ

With genuine respect, your explanation contradicts the statement by E Forster, he states;
"radiant energy flux is a vector that always flows from hotter to cooler objects".
This statement denies that there is a second vector from cold to warm i.e. no back radiation.

Nov 13, 2015 at 7:14 PM | Registered Commenter Dung

I did not give the whole of E Forster's statement because I did not wish to antagonise BYJ any more than usual :)
EForster is a member of the IET
(The IET, formerly the Institution of Electrical Engineers)
EForster said:
"I should add that members trained in electromagnetic theory are in a very good position to question “back radiation” nonsense and confirm that radiant energy flux is a vector that always flows from hotter to cooler objects. But this discussion has never surfaced probably for the same reason, to go with the flow and make money."

Nov 14, 2015 at 12:42 PM | Registered CommenterDung

Dung, dunno who E Forster is but what he says is dodgy - it is either unclearly expressed or it is outright wrong. It sounds suspiciously as if he may well be a member of the Brotherhood of Dragon Slayers.

(Some time ago, I wrote a review of their book You cannot debunk global warming pseudo-science with gobbledegook science )

http://www.amazon.com/review/R51AZXLVRA5AG/ref=cm_cr_dp_title?ie=UTF8&ASIN=0982773412&channel=detail-glance&nodeID=283155&store=books
(I hope my clickable link will work. I dare not test my link for fear of being 403'd. BISH! WHEN IS IT GOING TO BE DEALT WITH? IT'S A REAL PAIN.)

They believe nonsense which is at complete variance with standard radiation physics. For example, they are completely convinced that as radiation from a cooler body cannot be intercepted by a warmer body. (Dunno how they think the photons can remember the temperature of the body that ejected them.)

In fact:

All warm (ie above absolute zero) bodies radiate.

If two warm bodies (one warmer than the other) are in sight of each other both will radiate and each will receive thermal radiation from the other. The net flow of radiation is from the body at higher temperature to the body at lower temperature but there is always radiation going in both directions. It's just not open to dispute.

Nov 14, 2015 at 2:17 PM | Registered CommenterMartin A

My own mental image of energy flow and storage in the climate system is more like the MONIAC hydraulic model of the economy
Nov 14, 2015 at 11:54 AM | Unregistered CommenterEntropic man

I can well believe that, given your faith in simple formulas. Interesting question as to which is more amenable to modelling - the climate system or the economy.

Nov 14, 2015 at 2:35 PM | Registered CommenterMartin A

It sounds to me like this is about The Laws of Thermodynamics and two bunches of 'scientific' type people who argue about whether or not the laws are correct.
It reminds me of people arguing about Schrödinger's cat where an assumption has to be made or their sums do not add up ^.^
I am sure that some important technology only works if you assume that the Laws of Thermodynamics are correct in which case they have a point:)

Nov 14, 2015 at 2:43 PM | Registered CommenterDung

Martin A

I used forcing and feedback in biology, in homeostasis, ecology and population dynamics. I also encounted "forcing the blast",; pumping extra air through a blast furnace to make it run hotter and produce iron faster. This is not normally recommended because it damages the furnace.

You would need to consult a physicist to be sure, but the two concepts are probably necessary for understanding any process with an energy budget.

Nov 14, 2015 at 2:54 PM | Unregistered CommenterEntropic man

Martin A

What does your mental model of the climate look like?

I hope you have one, as you would probably had a mental model of the electron flow through your telephone networks.

Nov 14, 2015 at 3:03 PM | Unregistered CommenterEntropic man

Martin A

Nice review.

I would agree with 90% of it.

Nov 14, 2015 at 3:18 PM | Unregistered CommenterEntropic man

EM

(3:18) Thank you for the compliment.

(3:03) What does your mental model of the climate look like? I hope you have one, as you would probably had a mental model of the electron flow through your telephone networks.

My mental model of the climate? What does it look like? I suppose it looks like an impossibly complex (ie infinitely complex and not capable of meaningful simplification) physical system, continuous in three spatial dimensions, and continuous in time, with significant spatial dimensions from ranging from molecule size to planet size, with significant temporal dimensions ranging from sub-millisecond to hundreds of millenia, and with nonlinear interactions that will probably always remain beyond human understanding, plus with behaviour future behaviour that cannot be computed from its current state, for fundamental reasons. (ie it is chaotic at multiple levels.)

You'll have noticed that my mental model of the climate certainly does not look like a small number of interconnected hydraulic containers.

mental model of the climate / mental model of the electron flow through your telephone networks

The two things are simply not comparable. The detail of the operations of a telephone switching systems or of a datacommunication network are known and can, in principle, be described with complete precision.

They can be considered as discrete event systems with just a finite - although enormously large - number of possible states at any given instant. The rules describing how one state transitions to the next are precisely known. Such systems can, in principle (but only in principle), be simulated precisely.

Nov 14, 2015 at 6:51 PM | Registered CommenterMartin A

Dung

It sounds to me like this is about The Laws of Thermodynamics and two bunches of 'scientific' type people who argue about whether or not the laws are correct.

Nobody is arguing. The Laws of Thermodynamics are absolutely correct to the millionth decimal point. This isn't a debate with you presenting one interpretation of a scientific rule and me presenting another. It's you misunderstanding science, and me trying to educate you. The fact that I'm bad at educating and you are bad at learning does not change the underlying reality of the truth of the science. Because you disagree doesn't mean it's in dispute.

But like the alarmists, you appear to be very fond of the Argument From Authority, and that because some bloke you think is great (E Forster, whoever he is) says something you like then that trumps my science. Science doesn't work like that. There are no high priests. What he is doing is stating the facts in a way which are not incorrect, but which convey a different meaning to the lay reader. That would be you. He says the vector is from hot to cold, which is it. You take from that statement that there is no energy flow from cold to hot, which is incorrect. I'm sure he knows that. Either he has played fast and loose with the science for some reason of his own, or you have taken his words out of context, in confirmation bias.

There is no scientific dispute about the Laws of Thermodynamics. I this case, the science really is settled.

Nov 14, 2015 at 7:36 PM | Unregistered CommenterTheBigYinJames