Guest post by Bill DiPuccio, Science Teacher
Let’s face it, high school science videos can be boring and ineffective. I like my science with a twist of comic exaggeration. So I decided to produce a video with enough humor to keep the students awake, and enough depth to challenge them intellectually.
This 30 minute video on the Greenhouse Effect is the prototype for a possible new series: “Bill Scientific” (I gave it a personal imprint to infuse some warmth and presence). Unlike introductory videos which attempt to cover a broad field of knowledge in a short time, the goal of this prospective series is to drill down into specific, but pivotal, topics in the physical and earth sciences.
Rather than just spooning out information, each program would be designed around experiments (the simpler the better) that can be used to illuminate and verify crucial scientific principles. Students will see science in action and gain a better grasp of the empirical basis for scientific theories.
Of course, future programs will depend on the response from students, educators, and scientists, as well as securing funding. The “Greenhouse Effect” was shot and produced on amateur equipment and software. Despite these limitations, I believe the final product faithfully conveys the intent of series.
P.S. If you like the video, pass it on!
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_Jim 8.28: you fail to understand my point which is about the most basic theorem in physics.
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If two bodies are at equal temperature and have equal emissivity, the radiation from one to the other is exactly nullified by radiation going the other way. This is Prrevost’s Theory of Exchanges, the oldest Radiation Law, and you also have the associated Kirchhoff’s Radiation Law which is that over any wavelength interval at each body, emissivity = absorptivity.
So, if you were to place a spherical radiometer or spectrometer between the two bodies, it would measure nothing.
Most radiometers/spectrometers aren’t spherical. they consist of a shield which prevents radiation going one way from impacting the detector. So it views part of the flux. That’s when you see the net energy flow and the spectral characteristics but it does not measure any real energy flow, just temperature and emissivity.
Do you get it yet? Because meteorologists donn’t understand what the pyrgeometers actually measure, they have put into the climate models a fallacy about ‘back radiation’ – it’s an artefact of the measurement process and if you take my argument to any professional physicist he/she will confirm my point.
The problem is that radiation physics hasn’t really developed since the 1920s and Planck invented the photon as a throw-away concept. it isn’t real.
Apologies for failing to turn of the bold, also I should add that this argument applies to a detector pointing towards the cooler of the two bodies if they are not at the same temperature.
However, I am totally firm in pointing out that at some time since Manabe and Wetherald’s 1967 paper which assumed IR up = SW down, a gross exaggeration but not incorrect physics, climate science and the modelling has assumed the false S-B B-B argument and imaginary back radiation to justify it.
Hopefully it will soon be accepted that this whole exercise has been a stupid waste of money because the people supposed to be running the programme have failed in their most basic understanding of physics. No IPCC climate model can predict climate and as well as turning BH’s readers, Curry and Spencer I will turn you onto the path of correct bloody physics…………:o)
Russ in Houston says:
April 27, 2012 at 7:39 am
No link. Have you seen any experiment reported where a parcel of air was heated soley by the addition of CO2?
wmconnolley says:
April 27, 2012 at 8:10 am
…”.If you want to pretend that the GHE doesn’t exist, find someone else to talk to.”
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Umm, nobody was talking to you, those were voices in your head.
u.k.(us) says:> Umm, nobody was talking to you
When someone starts a comment with “Mr. Connolley please…” I tend to assume they are talking to me. It seems natural. Perhaps there are other Connolley’s known to comment here?
wmconnolley says:
April 27, 2012 at 11:07 am
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Sorry, couldn’t resist.
[Moderator’s Note: You didn’t really expect Dr. Connolley to roll over for that, did you? -REP]
Bill Illis says:
April 27, 2012 at 7:25 am
Now how often is cloud cover is present.
Nearly all the *%£$?@ur momisugly# time in England.
The fart at 4.9 made me laugh, fart tax. lol
While the video did a good job with the greenhouse effect, it only tells half the story. What happens to energy in the atmosphere? The GHE relates to energy radiated from the surface. The energy in the atmosphere is ignored. Energy enters the atmosphere from many sources (which was mentioned in passing). This energy gets radiated to space along with the surface energy. The details of that process are essential to understanding how the Earth’s temperature is maintained.
I believe that GHGs act as a thermostat in and of themselves. If the atmosphere gets warmer they act to cool it down. If the atmosphere cools they act to warm it up. This occurs because GHG thermalization is based on different processes than kinetic molecular excitation of GHGs, even though both occur as a result of collisions. Thermalization is primarily based on the amount of energy radiated through the atmosphere. If no energy is absorbed by GHGs there is nothing to thermalize. Excitation is based on the actual temperature of the atmosphere.
Two identical cars.
One filled with Co2 . I’d like to see that one.
RICH says:
April 27, 2012 at 7:53 am
If nitrogen and oxygen “absorb almost no radiation,” how are they warmed then?
Conduction from the ground, and so carrry the heat up by convection thus reducing ground radiation and subsequent back radiation.
(I made that up, not bad for a uneducated person eh?.)
Mydogsgotnonose : “If two bodies are at equal temperature and have equal emissivity, the radiation from one to the other is exactly nullified by radiation going the other way.”
But there are (at least) two ways something can be “nullified” — you can “stop the activity” or you can compensate for it. For example, if I have a pump pumping water through a pipe, I could “nullify” the flow of water by putting an identical pump on the other end of the same pipe, so that no water flows. Or I could get an identical pump and pipe, and pump an identical amount of water back the same way, resulting in no net flow.
You seem to be thinking that the “back-radiation” is like putting the pump on the same pipe, so that no photons move either way. In reality, it is more like two pumps and two pipes, so that photons are flying both ways. There is a “real flow” of photons downward from the atmosphere (which tends to be less than the upward flow from the surface).
PS Even your guy Prevost seems to agree with me. Wikipedia quotes Prevost as saying
This would support the view that equal amounts are going in each direction, and that both are “real”. He does NOT say “receiving no heat from each other”.
wmconnolley says:
April 27, 2012 at 8:10 am
mkelly says:> Mr. Connolley please write a radiative heat transfer equation… Please use 1 atm and 288 K
Read your Wiki link and it was not about heat transfer it was about fluxes.
When you and others get the understanding that in heat transfer when T1= T2 Q/A equals zero, then you will stop this nonsense that radiation from a cooler atmosphere will heat a hotter surface.
That is why I ask you and others to write HEAT transfer equations so you can come to the realization you’re wrong.
I quit after the first video. I can’t stand the factual errors, such as “most of the suns incoming energy is absorbed by the earths surface and radiated as infrared”, or words to that effect.
Ouch! Most of the suns energy is converted to water vapour!
Yikes!
Higley7 said
“but I’ll put money on the air cooling faster, given the heat conductivity of rock being slower than a gas. Thus, even at night, the atmosphere cannot warm the surface.”
Actually, the thermal conductivity of air is much lower than that of rock. Air is an excellent insulator if it is kept from moving. However, air easily moves heat energy from place to place by convection. Fiberglass batting used as insulation works well because it minimizes convective air currents. Air is a much better insulator than the glass.
At night, heat is transferred from the atmosphere to the earth’s surface where it is lost to space thru the atmospheric IR window between 8 to 14 microns. The evidence of this is easily seen on a cloudless still night as the surface temperature will drop several degrees lower than the air temperature due to this radiative cooling process. This temperature difference is minimized when there is even a slight breeze. Turbulent mixing of air near the surface continually provides the surface with supply of atmospheric heat, thus enhancing this nighttime heat transfer.
Calculations of the heat transfer between a gas and a solid usually are done by assuming a stagnant layer of gas exists at the surface whose thickness varies with gas velocity. It is the temperature difference across this boundary layer along with the thermal conductivity of the gas involved that determines the rate of heat transfer.
In reality, there is a barrier to air movement in the atmosphere at the tropopause, where convection currents normally stop. Just like the the roof on a greenhouse so the greenhouse analogy is not as flawed as some make it out to be.
Thanks to all of you for your thoughtful comments and thanks to WUWT for posting my work! Being the first attempt, there is certainly room for improvement in terms of both clarity and production.
Some of the criticisms were based on watching only part 1. I believe most of these were answered later in the program. For those of you who stuck with the program, there was a great emphasis on the dominance of water vapor as a greenhouse gas. As Forrest Mims demonstrated in his AMS article last year, IR sky temp corresponds directly with precipitable water rather than CO2.
The real test will be how this type of video is received by students and educators.
And, by the way, I can’t help it if I look kind of like Bill N– and happen to have the same first name!
Sorry. But I do not like the video. Too many scientific errors. Please educate yourself before you make future videos and please do not show this video to kids. It will only get them more confused.
I enjoyed the videos. To critique it, I would say pick up the pace a bit.
I began to fidget, look out of the window and I thought about making a spitwad. :-).
I have read in a few places where the GreenHouse Effect really doesn’t exist anywhere but in a greenhouse – or in this video.. a green car… one such paper is here:
http://arxiv.org/PS_cache/arxiv/pdf/0707/0707.1161v4.pdf
In the abstract it states.. “Ac- cording to the second law of thermodynamics such a planetary machine can never exist.”
Although the video is well intended, it really doesn’t do a very good job of giving all ‘scientific’ sides to greenhouse effects…
Hi Tjfolkerts:
Same thing applies: put a plug between the two systems and the net pressure on either side of the plug is real, but nullified by he equal and opposite pressure the other side.
The plug shrinks a bit………
‘Back radiation’ is imaginary…….
Greenhouse analogies are fraught with confusion.
It’s easier to just start with the actual science and experiements
http://nsdl.org/sites/classic_articles/Article3.htm
http://nsdl.org/archives/onramp/classic_articles/issue1_global_warming/n3.Tyndall_1861corrected.pdf
To me it is a very well done misleading propaganda video.
No references to key claims, I am not surprised.
Hi W. M Connolley, since your expertise is to edit wikipedia articles, be sure to correct the one you suggest: http://en.wikipedia.org/wiki/Greenhouse_effect#Real_greenhouses
Where is written:
“In the greenhouse effect, rather than retaining (sensible) heat by physically preventing movement of the air, greenhouse gases act to warm the Earth by re-radiating some of the energy back towards the surface. This process may exist in real greenhouses, but is comparatively unimportant there.”
There’s an error made by some naif people that use to edit wikipedia. Greenhouse gases do not re-rediate some of the energy back towards the surface since the molecules do not have any infinite common orientation that forces the re-emitted radiation only to the surface. Radiation is re-emmited in all directions, including the earth’s surface. The reason why this effect is more intense near the surface it’s because CO2 is more concentrated here and not because it “re-emmits” to the surface. Sorry for my english, but I guess that you’ll understand the physical process. Please edit the Wikipedia article to correct this common “naif” error. The heat transfer processes are a lot more complex than this and this “re-radiation” effect of CO2 is largely over rated.
From a real climate scientist…
montanaconserv writes: “I have read in a few places where the GreenHouse Effect really doesn’t exist anywhere but in a greenhouse … “
One constant problem is that “the greenhouse effect” means different things to different people. I suspect it would not be difficult to find a dozen or more significantly different variations on definitions for “the greenhouse effect.” So before stating whether or not it exists, it is important to state clearly which specific version of “the greenhouse effect” you mean.
Beyond the definitions, people often use analogies, which creates further problems. Saying the atmosphere acts “like a blanket” has some elements of truth, but has a lot of problems, too. The paper you referenced says the greenhouse effect “essentially describes a fictitious mechanism, in
which a planetary atmosphere acts as a heat pump …” which is also a poor analogy (and then makes it easier for the authors to attack the poorly defined “greenhouse effect”.
To me the one key idea in “the greenhouse effect” (as related to the atmosphere, not actual buildings) is that the atmosphere is (mostly) transparent to sunlight, but (significantly) opaque to “earthlight”. This provides a mechanism for the atmosphere to send some energy back to the surface. Many OTHER effects (like evaporation and convection) ALSO affect the temperature at various points, but they are SEPARATE from what I consider to be “the greenhouse effect”.
Maybe I should start a collection of different versions and then let people pick which one they are attacking or supporting….
Sorry Spartacus: CO2 is not concentrated near the surface: it is well mixed.
Your argument is based on the assumption of 100% direct thermalisatin. That is not true: probably it’s indirect at clouds, and bare aerosols.