After the essays in May on mirrors and light bulbs, I’ve been regularly poked and prodded via email for not wanting to engage “the slayers” anymore, or to do that “third experiment” I mentioned in May. I long ago concluded by my experiences afterwards with “the slayers” that it is a waste of time and effort to try to explain anything to them. Curt Wilson, who did the second experiment and was planning to do the third, has come to the same conclusion, as have many others.
I have to give them credit though, they are entertaining. When I saw this profoundly ridiculous rebuttal (reflectional denial) at their headquarters while arguing over Willis’ Steel Greenhouse post, I just had to share it.
LOL! That’s the “slayers” in nutshell right there. No better example of the absurdity of their position exists in my opinion. Epic.
WUWT regular, Duke physicist Dr. Robert G. Brown has been trying to talk some sense into them over at Principia Scientific. I keep telling him he’s being sucked into a time and energy sink like gravity around a neutron star. Just as it is a good policy to steer clear of neutron stars, so it is with these folks who are incapable of assimilating the real world of physics, but live in an alternate reality of absurd second law constructs.
So, that’s why I’m not bothering anymore, when you have reflection denial statements like the one above, why engage in a pointless dialog with the hopelessly lost who don’t want to learn anything? Thank goodness for my spam filter.
For those that might care, keeping the filament of a lightbulb within its optimum temperature range increases its life, by limiting hotspots and thus tungsten evaporation. Putting an incandescent bulb into a reflector housing not designed for it will in fact increase the filament temperature, increasing tungsten evaporation and deposition on the inside bulb glass surface.
See: http://www.lightingassociates.org/i/u/2127806/f/tech_sheets/FAQs_Reflector_Design__Why_is_it_important_.pdf
Tungsten evaporation from hotspots is why standard incandescent bulbs eventually fail.
Boiler design says: “Earth has incredibly fine temperature control system, more energy from sun, more CO2 from oceans, more radiation to space.”
Close .. but the last step is reversed (which completely undoes your argument). The CO2 in the atmosphere is already emitting thermal IR to space. if you add more CO2, it will BLOCK the IR from lower layers and emit INSTEAD from the higher layers (that currently have too little CO2 to emit efficiently). The higher layers are COOLER (due to the lapse rate) so the emissions from the CO2 in the new higher top layer will be LESS than the emissions from the old lower top layer.
“””””””…….Bryan says:
July 21, 2013 at 2:12 am
george e. smith, you appear to be saying that if semiconductor material is heated its resistance goes up.
I hope you agree with me that all commonly freely available sources (such as wikipedia) say exactly the opposite.
For example what is this person up to;
http://www.isb.ac.th/hs/jos/vol4iss1/Papers/1LEDTemp.pdf
Is he inventing data for an experiment that never happened?
Yet you claim that a highly specialised textbook supports your statements.
Further you appear to have worked in the semiconductor industry.
Why there should be such a disconnect between specialised and general literature is not obvious…..”””””
Well the Wikipedia reference somebody posted did not lead to anything; must be a wrong link.
But the reference you give, is almost hilarious.
No, the math in it is not unfamiliar; extremely familiar, in fact; but what your author gives, has nothing to do with the resistivity of semiconductor materials.
It is in fact a standard for for the usual I / V characterstic of a semiconductor diode, which is an entirely different proposition. It is NOT a formula for resistance at all.
Semiconductor diodes DO NOT obey Ohm’s law.
There isn’t any disconnect between specialized literature and general literature. It is misapplication that causes problems.
People see an equation that has Voltage in it, and current, and they jump to the conclusion that it must be a resistor.
Well an electric motor operates with a Voltage, and a current, but it certainly doesn’t obey Ohm’s law
“””””…..Itotal = Io exp(-eV/kT) [2] (Equation 1)…..”””””
pasted from your reference.
The Io ( I zero) is NOT a constant. It is the reverse saturation leakage current, that you get (ideally) when you reverse bias a semiconductor diode. Io is very highly dependent on Temperature.
In the exponent part, kT/q has a value at room Temperature of about 26 milliVolts. So the equation says, that the current increases by a factor of e (2.71828) every time the Voltage is increased by 26 milliVolts. That is true almost independent of what the semiconductor is.
Germanium, Silicon, Gallium Arsenide or GaasP (old red LED material), all of them, the current increases by e times every 26 milliVolts. That also works out to be about 60 mV per decade.
Now, there is that (n) in there, which is a factor ( between 1 and 2) that depends on whether the current is dominated by diffusion current, or by recombination current.
But for most practical devices, the 60 mV per decade is what most semiconductor engineers, know better than they know the value of Pi.
But if you run any diode in its normal region at any constant current, the forward Voltage will drop 2 milliVolts per deg C increase in junction Temperature; doesn’t matter much which semiconductor. The actual Voltage, changes with semiconductor material, but they all have the same -2 mV/deg C change in Vf. But that is not due to a resistance change.
tjfolkerts says:
July 21, 2013 at 12:22 pm
“…if you add more CO2, it will BLOCK the IR from lower layers and emit INSTEAD from the higher layers (that currently have too little CO2 to emit efficiently).”
There is not nearly enough at higher altitude to block what is coming up from below to any level of significance. This is not even close to a first order effect.
Greg House says:
July 21, 2013 at 10:10 am
My position is that whatever some people imagine about what might happen to the radiation, back radiation of any kind can not warm the source, because the assumption of the opposite leads to absurd results, see the explanation above.
If the energy contained in any radiation, in this case a package called a photon, is not conserved, one is breaking the 1st Law of conservation of energy…
Assuming that any individual photon released from a colder object that hits a warmer object is absorbed, it will heat the warmer object. Even if that is a miniscule effect for one photon.
Does that break the 2nd Law? Not at all, as the total energy transfer (transmitted via photon packages) from the warmer to the cooler object is larger than what is transmitted from the cooler to the warmer one.
Does that increase the temperature of the warmer object? Yes it does. The total energy balance must be conserved. Thus if the warmer object receives some energy from a colder one, it will either cool down less fast in the case of a one time heatup (from an intermittent energy source like the sun), or it will heat up further with a constant internal heat source.
Bart says: “… so you’ve still got it [CO2] radiating at low altitude, if anything at greater quantity than before.
Yes, more CO2 will radiate a bit more (or more specifically, will absorb and emit over shorter distances). But this not a big deal.
“… half of which is, yes, re-emitted back to the surface.”
Not exactly. The radiation down from the atmosphere (in the band that GHGs emit) is about EQUAL to the upward radiation, not about HALF.
It is more accurate to say that ALL of the upward radiation gets absorbed by the GHGs (if it is in their bands). The GHGs in the lower atmosphere then emit THEIR OWN RADIATION that is about equal (slightly less) in intensity because it is about the same temperature (slightly cooler). This is the radiation that returns .. not ‘half of the ground’s radiation’.
*****************************************
The key point is not what happens within the atmosphere. The key point is what happens at the TOP. This is where the energy escapes to space, so this is where the changes to the overall energy balance occur. The radiation from the top will decrease as more CO2 is added.
Bart says: “There is not nearly enough at higher altitude to block what is coming up from below to any level of significance. This is not even close to a first order effect.”
At some levels (near the surface) it is a very STRONG effect. At some levels (say 50 km up) is is indeed “not even close to a first order effect” as you say.
The point is that there is a continuously decreasing concentration. Each layer is a little less effective at blocking the photons from below (and creating their own photons). There will be SOME altitude at which 50% of the photons coming up are allowed through. With more CO2, that 50% level will be a little higher, and the photons that escape will be coming from a greater altitude. That translates to fewer photons escaping to space.
Boiler Designer says (July 21, 2013 at 11:41 am): “What happens to tempertaure if we take CO2 away from the atmosphere, atmosphere becomes much more hotter than with CO2, less heat radiation to space.”
Thanks for the clarification, BD. If I’m reading you right, you’re saying that so-called “greenhouse gases” may have a net cooling effect, rather than the net warming effect assumed by both CAGW alarmists and skeptics?
Gary Hladik says:
July 21, 2013 at 11:01 am
“How do you explain a radiation shield increasing the temperature of a vacuum furnace heating element?”
==========================================================
The abstract you linked your words to does not say anything about “increasing the temperature of a vacuum furnace heating element”. The shields are apparently supposed to protect the environment from the heat.
This is your link: http://jpsj.ipap.jp/link?JPSJ/11/1184 and this is the full text: “A method for calculating the efficiency of several sheets of thick radiation shields with finite thermal conductivity is presented. It is shown that in case of shields having infinite conductivity, the efficiency and temperatures of the shields are expressed by simple formulas. It is shown by several examples of this method of calculations that the most important factors for the efficiency are found to be emissivity, thermal conductivity of the innermost shield and its position. Effectiveness of a shield with small conductivity, which we call `thermal shield’ in this paper, especially at high temperature is emphasized. Several experimental results are shown; they agree satisfactorily with the calculations.”
So, no “back radiation warming effect” is claimed there.
Did you make it up, Gary, or was it a misunderstanding?
Ferdinand Engelbeen says:
July 21, 2013 at 1:15 pm
“Assuming that any individual photon released from a colder object that hits a warmer object is absorbed, it will heat the warmer object.”
==========================================================
No, it won’t, because the this assumption leads to an absurd result, which proves the assumption false, see the explanation and the calculation above. The calculation for 2 blackbodies is similar and leads to the same conclusion.
tjfolkerts says:
July 21, 2013 at 12:11 pm
“…you always revert to your “soundbite science” and your own personal interpretation of the 2nd Law .”
==========================================================
My refutation of the “greenhouse effect” above contains no reference to the 2nd Law at all and is not based on it.
On the other hand, your and others’ misinterpretation of the 2nd Law is interesting, so I comment on it sometimes.
tjfolkerts says:
July 21, 2013 at 1:18 pm
“It is more accurate to say that ALL of the upward radiation gets absorbed by the GHGs (if it is in their bands). “
No, this is not correct. It depends on the concentration. If there is one molecule of CO2 at 20 km, it is not going to intercept everything coming at it from below 20 km.
“The radiation from the top will decrease as more CO2 is added.”
All things being equal, that would be the case (though, all things are decidedly not equal, which is why we haven’t observed any definite warming effect from CO2). However, it is because the increased concentration of CO2 would intercept more outbound IR. It has little to do with the altitude at which it is intercepted.
Greg House says (July 21, 2013 at 1:44 pm): ‘The abstract you linked your words to does not say anything about “increasing the temperature of a vacuum furnace heating element”.’
I had no problem downloading the full text. Does that not work for you?
Bart,
Sorry, in the context of the original statement, I thought is was clear I was still discussing your “low altitude” scenario. Let me be just a little clearer:
““It is more accurate to say that ALL of the upward radiation FROM THE SURFACE gets absorbed by the GHGs (if it is in their bands). “
The concentration of CO2 near the surface is such that the IR in the 15 um absorption band only travels a few 100 m (maybe less) before is it 99.999% absorbed.
Bart goes on to say: “However, it is because the increased concentration of CO2 would intercept more outbound IR.”
That would be part of the effect … the edges of the bands where absorption are poor will be blocked better with more CO2. But the centers of the bands are already absorbed 100% in relatively short distances near the surface, so adding more CO2 cannot intercept more than 100%. Of course, this changes as you get high in the atmosphere — which was my original point.
So both the “broadening of the band” effect and the “raise the top-of-atmosphere” effect both serve to decrease the IR emitted to space (and hence lead to warming).
My intuition says that the “raise the top-of-atmosphere” effect will be more significant. But either way it leads to warming of the surface.
Gary Hladik says:
July 21, 2013 at 3:22 pm
“I had no problem downloading the full text. Does that not work for you?”
==============================================================
Gary, first of all, definitely no reader would pay for the full text of this hidden behind the pay wall article just to prove that you
liedmade a mistake.Besides, common sense is practically screaming that if the authors had claimed increasing efficiency of a furnace by back radiation warming, they would have certainly said it clearly in their abstract. They didn’t. Try it better next time. And thank you for this wonderful revealing example.
Greg House says:
July 21, 2013 at 9:59 am
Tsk Tsk says:
July 20, 2013 at 8:45 pm
“See, I let you use instantaneous heating of the plate on the original 400W cycle, which means you have to let me use instantaneous cooling.”
=============================================================
The “greenhouse effect” is claimed to produce warming, not cooling, hence your derivation is not about the “greenhouse effect” any longer.
To see the absurd result of the assumption of the “greenhouse effect” you need to strictly stick to this assumption, not to jump from this assumption to the reality back and forth or even invent other absurd things.
==========================================================================
OK, admit it. Now you’re just being facetious. In order for your “example” to work you have to have effectively instantaneous heating and by extension instantaneous cooling. And since the plate is physically isolated from everything else the only mechanism to achieve that is through radiation. And in order to truly obey the second law (and the first) emissivity and absorptivity have to be the same. If they weren’t then we truly would have a perpetual motion machine. But that’s exactly what you created with your error. It’s only through your integration error that you get the result that you want. My “cooling” is nothing other than blackbody radiation which is your warming and is perfectly consistent with the GHE.
Finally, I’ll note that you didn’t or couldn’t answer how nature knows to raise the temperature of the plate when we raise the temperature of the cold sink. How do you suppose that information propagates between them?
Gary Hladik says (July 21, 2013 at 3:22 pm): “I had no problem downloading the full text. Does that not work for you?”
Aha! I found the problem. I’m using my wife’s “old” computer, which still has her faculty access to many academic publications. I disabled the proxy server and lost free access to the article. 🙁
So Greg, if you really think I’m “making it up” you can buy the article for 2000 yen (~$20) and prove your accusation, or you can take my word for it. Meanwhile, I’ll look for something more accessible.
Greg House 7/21 2:32pm: “My refutation of the “greenhouse effect” above…”
If you mean above at 7/19 5:02pm, then you have provided no successful GHE refutation therein.
tjfolkerts offers an explanation why your refutation is not successful at 7/19 5:57pm which you incorrectly hand wave away.
For your claim “My refutation of the “greenhouse effect” above…” to be successful at the most basic level, you will need to prove that massive bodies with T>0K do not all radiate in IR bands.
Earth’s atm. is a massive body with T>0K, so it must radiate in IR bands toward earth’s surface. Prove that wrong, and you will have your refutation.
From my reading of your words, you confuse warming with heat. Heat is no longer a noun. Heat is only an adjective as in heat transfer. Where you use “heat” as a noun, or replace “heat” with “warming”, your science is lacking modern skill.
Do not be alarmed! This happens to many, even those with more skill that you demonstrate. Especially in the field of study of Ocean Heat Content. Oh man, don’t go there with me.
In your example, nature protects against your proposed runaway with reflectors that are not perfect. Made real, your 7/19 5:02pm system will not runaway; it will equilibrate with surroundings at a higher temperature than before your reflector was placed. The real equilibrium temperature will not be infinite (as tjf tries to show you) even with a darn good internal battery. Nature protects.
tjfolkerts says:
July 21, 2013 at 3:31 pm
“But either way it leads to warming of the surface.”
With the obligatory “all things being equal”. Because it has become quite apparent that all things are not equal, and the increase in CO2 is having little actual effect due, very likely, to powerful negative feedback effects.
Moreover, I assert that your specific mechanism is falsified by the fact that it creates a positive feedback, which at the very least would lead to far greater variability in temperature and CO2 than is observed.
Tsk Tsk says:
July 21, 2013 at 5:00 pm
“In order for your “example” to work you have to have effectively instantaneous heating and by extension instantaneous cooling.”
=======================================================
Last time I checked the notion of “greenhouse effect” suggested warming, not cooling.
I understand you desire, you know, to somehow insert cooling into the absurd “greenhouse effect” to avoid it’s absurd consequence, but you can not have it. Blame the IPCC&Co for that, not me.
Tsk Tsk says:
July 21, 2013 at 5:00 pm
“In your example, nature protects against your proposed runaway with reflectors that are not perfect. Made real, your 7/19 5:02pm system will not runaway; it will equilibrate with surroundings at a higher temperature than before your reflector was placed. The real equilibrium temperature will not be infinite (as tjf tries to show you) even with a darn good internal battery.”
==========================================================
I can sense wishful thinking on your side. You did not check it, did you? Please, do a similar calculation assuming the reflector returns only the half of what it gets and report the result.
Greg House says (July 21, 2013 at 4:45 pm): “Besides, common sense is practically screaming that if the authors had claimed increasing efficiency of a furnace by back radiation warming, they would have certainly said it clearly in their abstract. They didn’t.”
That’s just it, Greg. As they wrote in their introduction, the increase in efficiency was well known even in 1956. Their contribution was just an improved way to predict the actual efficiency gain from various types of shields.
“Try it better next time.”
Not really much point, is there? As we saw with the dichroic light bulb example (complete with product brochure and scientific papers), you’re impervious to facts. Every one of your comments in this thread has only reinforced that.
“And thank you for this wonderful revealing example.”
My pleasure. Thank you for the laughs. I mean, “The greenhouse effect will melt your face!!!! Aaaaah!” Priceless. 🙂
Gary Hladik says:
July 21, 2013 at 8:29 pm
“That’s just it, Greg. As they wrote in their introduction, the increase in efficiency was well known even in 1956. Their contribution was just an improved way to predict the actual efficiency gain from various types of shields.”
========================================================
Efficiency of protecting the environment from the inside heat by the shields, nothing more.
Now I do not believe any longer that it might have been a misunderstanding on your side. I think you lied, on purpose, hoping that nobody would really read your link. The IPCC&Co style.
Anyway, it is my strong opinion, others may have theirs.
Greg … think about what you just said! “Efficiency of protecting the environment from the inside heat by the shields”
The ‘protection of the environment’ means less heat getting out to adversely warm the surroundings. By conservation of energy, this mean the heating elements are providing less power than they would without without the radiation shields in order to reach the same temperature. Your own statement backs this up!
But the furnace is still just as hot as before on the inside. Low energy loss with the shields; high energy loss without the shields. We can produce the same temperature with less power input.
Let’s continue …
Remove the radiation shields (keeping the power to the heating elements constant now) … and the furnace will cool down in the interior. Add the shields back (still at constant power) and the furnace will warm up.
Yep, the cold shields, in conjunction with the steady heater, have caused the warm interior to get even warmer. All in a vacuum where there is no conduction or convection .. only ‘back-radiation’ to affect the furnace temperature.
“Cool+hot is warmer than cold+hot”
Greg House says (July 21, 2013 at 9:11 pm): “Efficiency of protecting the environment from the inside heat by the shields, nothing more.”
Only in the sense that the shield(s) reduces the power needed to achieve a given core temp, so less heat is dissipated to the “environment”.
“Now I do not believe any longer that it might have been a misunderstanding on your side. I think you lied, on purpose, hoping that nobody would really read your link. The IPCC&Co style.”
Thanks for living down to my expectations, Greg. FYI, you’re also accusing “chris y” of lying.
For those with a functioning brain still reading this thread, I’ve found another real life variant of the “Yes, Virginia” experiment that should be accessible to everyone. This paper describes a compact vacuum furnace for use in orbit, where weight, space, and power are critical. The paper describes a number of design measures to reduce power consumption, but as the author writes in the introduction, “…radiant heating dominates heat transfer in the furnace at all temperatures…” so the project concentrated on efficient radiation shielding.
I suggest reading the entire paper for full comprehension, but for the money quotes skip down to the “Low Power Testing” heading, where the author writes,
“The first test of the furnace design gave 115 W of power used at a coil temperature of 600°C. This is to be compared with the exact same furnace using vacuum insulation except with a quartz outer shell [i.e. without radiation shield] that operated at the same core temperature, but used a power of almost 2 kW.”
Further work on the radiation shielding reduces the power input to 80 watts for the same 600°C operating temperature. Note (again) that the author sees nothing remarkable about using radiation shielding to raise core temp (or, equivalently, maintain core temp with lower power input). Only the Pink Unicorn Brigade sees this kind of thing as face-melting voodoo science. 🙂
george e. smith, you appear to be saying that if semiconductor material is heated its resistance goes up.
A simple yes or no reply on this central point would have cleared the matter up
My last post gave you the chance to set the record straight but instead you dodged the central point
I hoped that you would agree with me that all commonly freely available sources (such as wikipedia) say exactly the opposite that is that the resistivity goes down as the temperature goes up.
Here is the wiki reference that you found hard to find from the link I provided.
Semiconductors[edit]
Main article: Semiconductor
In general, resistivity of intrinsic semiconductors decreases with increasing temperature. The electrons are bumped to the conduction energy band by thermal energy, where they flow freely and in doing so leave behind holes in the valence band which also flow freely. The electric resistance of a typical intrinsic (non doped) semiconductor decreases exponentially with the temperature:
This is also the opinion of all the physics textbooks I have looked up
University Physics – Harris Benson 1996 edition page 537
Essential Principles of Physics – Whelan & Hodgson 1978 Edition page 354
University Physics – Young & Freedman 1996 edition page 804