Guest post by Ira Glickstein
A real greenhouse has windows. So does the Atmospheric “greenhouse effect”. They are similar in that they allow Sunlight in and restrict the outward flow of thermal energy. However, they differ in the mechanism. A real greenhouse primarily restricts heat escape by preventing convection while the “greenhouse effect” heats the Earth because “greenhouse gases” (GHG) absorb outgoing radiative energy and re-emit some of it back towards Earth.
The base graphic is from Wikipedia, with my annotations. There are two main “windows” in the Atmospheric “greenhouse effect”. The first, the Visible Light Window, on the left side of the graphic, allows visible and near-visible light from the Sun to pass through with small losses, and the second, the Longwave Window, on the right, allows the central portion of the longwave radiation band from the Earth to pass through with small losses, while absorbing and re-emitting the left and right portions.
The Visible Light Window
To understand how these Atmospheric windows work, we need to review some basics of so-called “blackbody” radiation. As indicated by the red curve in the graphic, the surface of the Sun is, in effect, at a temperature of 5525ºK (about 9500ºF), and therefore emits radiation with a wavelenth centered around 1/2μ (half a micron which is half a millionth of a meter). Solar light ranges from about 0.1μ to 3μ, covering the ultraviolet (UV), the visible, and the near-infrared (near-IR) bands. Most Sunlight is in the visible band from 0.38μ (which we see as violet) to 0.76μ (which we see as red), which is why our eyes evolved to be sensitive in that range. Sunlight is called “shortwave” radiation because it ranges from fractional microns to a few microns.
As the graphic indicates with the solid red area, about 70 to 75% of the downgoing Solar radiation gets through the Atmosphere, because much of the UV, and some of the visible and near-IR are blocked. (The graphic does not account for the portion of Sunlight that gets through the Atmosphere, and is then reflected back to Space by clouds and other high-albedo surfaces such as ice and white roofs. I will discuss and account for that later in this posting.)
My annotations represent the light that passes through the Visible Light Window as an orange ball with the designation 1/2μ, but please interpret that to include all the visible and near-visible light in the shortwave band.
The Longwave Window
As indicated by the pink, blue, and black curves in the graphic, the Earth is, in effect, at a temperature that ranges between a high of about 310ºK (about 98ºF) and a low of about 210ºK (about -82ºF). The reason for the range is that the temperature varies by season, by day or night, and by latitude. The portion of the Earth at about 310ºK radiates energy towards the Atmosphere at slightly shorter wavelengths than that at about 210ºK, but nearly all Earth-emitted radiation is between 5μ to 30μ, and is centered at about 10μ.
As the graphic indicates with the solid blue area, only 15% to 30% of the upgoing thermal radiation is transmitted through the Atmosphere, because nearly all the radiation in the left portion of the longwave band (from about 5μ to 8μ) and the right portion (from about 13μ to 30μ) is totally absorbed and scattered by GHG, primarily H2O (water vapor) and CO2 (carbon dioxide). Only the radiation near the center (from about 8μ to 13μ) gets a nearly free pass through the Atmosphere.
My annotations represent the thermal radiation from the Earth as a pink pentagon with the designation 7μ for the left-hand portion, a blue diamond 10μ for the center portion, and a dark blue hexagon 15μ for the right-hand portion, but please interpret these symbols to include all the radiation in their respective portions of the longwave band.
Sunlight Energy In = Thermal Energy Out
The graphic is an animated depiction of the Atmospheric “greenhouse effect” process.
On the left side:
(1) Sunlight streams through the Atmosphere towards the surface of the Earth.
(2) A portion of the Sunlight is reflected by clouds and other high-albedo surfaces and heads back through the Atmosphere towards Space. The remainder is absorbed by the Surface of the Earth, warming it.
(3) The reflected portion is lost to Space.
On the right side:
(1) The warmed Earth emits longwave radiation towards the Atmosphere. According to the first graphic, above, this consists of thermal energy in all bands ~7μ, ~10μ, and ~15μ.
(2) The ~10μ portion passes through the Atmosphere with litttle loss. The ~7μ portion gets absorbed, primarily by H2O, and the 15μ portion gets absorbed, primarily by CO2 and H2O. The absorbed radiation heats the H2O and CO2 molecules and, at their higher energy states, they collide with the other molecules that make up the air, mostly nitrogen (N2), oxygen (O2), ozone (O3), and argon (A) and heat them by something like conduction. The molecules in the heated air emit radiation in random directions at all bands (~7μ, ~10μ, and ~15μ). The ~10μ photons pass, nearly unimpeded, in whatever direction they happen to be emitted, some going towards Space and some towards Earth. The ~7μ and ~15μ photons go off in all directions until they run into an H2O or CO2 molecule, and repeat the absorption and re-emittance process, or until they emerge from the Atmosphere or hit the surface of the Earth.
(3) The ~10μ photons that got a free-pass from the Earth through the Atmosphere emerge and their energy is lost to Space. The ~10μ photons generated by the heating of the air emerge from the top of the Atmosphere and their energy is lost to Space, or they impact the surface of the Earth and are re-absorbed. The ~7μ and ~15μ generated by the heating of the air also emerge from the top or bottom of the Atmosphere, but there are fewer of them because they keep getting absorbed and re-emitted, each time with some transfered to the central ~10μ portion of the longwave band.
The symbols 1/2μ, 7μ, 10μ, and 15μ represent quanties of photon energy, averaged over the day and night and the seasons. Of course, Sunlight is available for only half the day and less of it falls on each square meter of surface near the poles than near the equator. Thermal radiation emitted by the Earth also varies by day and night, season, local cloud cover that blocks Sunlight, local albedo, and other factors. The graphic is designed to provide some insight into the Atmospheric “greenhouse effect”.
Conclusions
Even though estimates of climate sensitivity to doubling of CO2 are most likely way over-estimated by the official climate Team, it is a scientific truth that GHGs, mainly H2O but also CO2 and others, play an important role in warming the Earth via the Atmospheric “greenhouse effect”.
This and my previous posting in this series address ONLY the radiative exchange of energy. Other aspects that control the temperature range at the surface of the Earth are at least as important and they include convection (winds, storms, etc.) and precipitation that transfer a great deal of energy from the surface to the higher levels of the Atmosphere.
I plan to do a subsequent posting that looks into the violet and blue boxes in the above graphic and provides insight into the process the photons and molecules go through.
I am sure WUWT readers will find issues with my Atmospheric Windows description and graphics. I encourage each of you to make comments, all of which I will read, and some to which I will respond, most likely learning a great deal from you in the process. However, please consider that the main point of this posting, like the previous one in this series, is to give insight to those WUWT readers, who, like Einstein (and me :^) need a graphic visual before they understand and really accept any mathematical abstraction.
Myrrh says “Light energies, Solar of Visible, UV and Near IR, DO NOT HEAT THE EARTH.”
But the very site he links to says “Ala. Biologists have found that cells exposed to near-infrared light from LEDs, which is energy just outside the visible range, grow 150 to 200 percent faster than cells not stimulated by such light. ”
The LED IR emitters that are being touted as heating tissues typically operate in the 0.8 – 1.0 um near IR part of the spectrum – the very part of the spectrum that is “reflective” and “cannot heat things”.
Well I made the mistake of looking at this thread at home over the weekend; and a quick summary of the weekend posts suggests that far more heat was generated than light; and in my view that’s not cool.
There still seems to be a belief by some posters, that electromagnetic radiation (either a wave or photons; your choice) in a certain wavelength range is “heat” and other wavelengths; the UV, Visible, near IR are not; how about radio/TV/microwaves; are they “heat”.
Well of course not. No electromagnetic radiation, from down to but not including DC, up to the farthest reaches of the cosmic gamma ray spectrum is “heat”, or “hot”, or anything else related to “Temperature”, which is a property only of real physical materials, that can be found in the periodic table of elements, and combinations thereof.
What scientists call “heat”, is the mechanical ENERGY of translation, vibration or rotation and other mechanical oscillatory motions of real physical particles like atoms or molecules. It is in a sense the trash heap of the energy world, in that once you “have it”, you are sort of stuck with it, in the sense that you can never turn ALL of it, into something else which is useful; like Electricity for example.
Any other form of energy can be turned into heat, either partially, or completely; and what lay folks refer to as “heat” is simply the result of turning some other form of energy; which can include EM radiation; once again, all the way from down to but not including DC, up to the end of the gama ray spectrum (orbeyond), into the waste mechanical energy of some physical matter; and for most people that is a result of absorption of EM radiation by mostly water in the human body; that’s what WE feel as “heat”. But we can also get it from a piece of iron, that was heated to several hundred degrees C, by simply grabbing hold of it.
For those who beli3eve that most of sunlight cannot “heat” the earth; perhaps you could explain to us, what it is that that non-heating EM energy does.
We know that the vast majority of it propagates deeply into the oceanic waters to several hundred meters; and never re-emerges for a very long time; yet it pours in there all day long while the sun shines.
So what does it become; that NON-HEATING solar energy, that enters the ocean and doesn’t come right back out again still as solar spectrum EM rays. Presumably it doesn’t just disappear; that would be a first law violation. I’m sure some of it is absorbed by living organisms, that may do all sorts of things with it; most mpost of the ocean waters don’t have living organsims everywhere to use the sunlight for something.
I’m curious to hear what you folks think happens to all that non-heating solar UV and Visible, and near IR sunlight that is NOT “heat”.
I have a sneaking suspicion that Phil would also like to know what happents to that stuff.
George E. Smith says “I’m curious to hear what you folks think happens to all that
non-heatingsolar UV and Visible, and near IR sunlight that is NOT “heat”.Well, I’ll take a stab ….
Since average temperature of the oceans (and hence total energy) is staying pretty constant, there must be (approximately) the same energy leaving the oceans as entering. The incoming IR/visible/UV energy must be balanced with a similar amount of outgoing energy. A good chunk of this outgoing energy is evaporation. A larger chunk is thermal IR coming back out of the oceans. There could be other places for the energy to go (like a net warming of the oceans or convection of hte air drawing energy up from the surface) but I am pretty sure these are relatively small compared to evaporation & upward IR.
“”””” Tim Folkerts says:
March 7, 2011 at 12:47 pm
George E. Smith says “I’m curious to hear what you folks think happens to all that non-heating solar UV and Visible, and near IR sunlight that is NOT “heat”.
Well, I’ll take a stab …. “””””
Well Tim, what you say is of course true; but those energy exit processes you mention all take place because that incoming solar spectrum energy, is in fact converted to waste “heat” in the deep ocean; which of course was my point. ANY EM radiation of ANY wavelength can be converted to “heat”; BUT is NOT of itself “heat”.
EM “THERMAL” radiation is NOT some special range of wavelengths that we call “heat”; it is EM energy (Photons) that arises solely because of “Thermal processes” namely molecular agitations, and collisions that is what “heat” is all about. In particular “Thermal” EM radiation is not Atomic Line spectra, nor is it Molecular Band spectra, (which Phil has painstakingly pointed out that N2 Na O2 are largely inactive on; both theoretically, and experimentally). Therm,al radiation is also NOT Synchrotron Radiation; nor is it Bremsstrahlung; it is not Gamma radiation; at least certainly not at earth atmospheric Temperatures.
And “thermal radiation” is produced within an envelope that is the Planckian Black Body Spectral distribution; modified by some spectral emissivity, that may be very much less than 1.0 specially for gases (any gases, including monoatomic, homo- diatomic molecules, or even GHG molecules. HCl is a perfect example of a non homo-diatomic molecule that is quite IR active; for the very simple reason that even though it only has two atoms, it most assuredly does have a dipole electric moment.
Thermal radiation of course does not require any dipole moment in the isolated atom or molecule; because it is a radiation whose origin is in the collisions of atoms or molecules; which is evidently described as “Collision Induced radiation” (I’ll buy that).
But what Phil spent a lot of time and energy pointing out was that N2 and O2, lacking a dipole moment in the isolated molecules are NOT IR active, in the molecular band spectra sense; although perfectly amenable to collision induced thermal emissions; which evidently are still low intensity, because of the molecular sparseness, and low energies at ordinary atmospheric conditions.
ANY electro-magnetic radiation (waves or photons), of ANY wavelength is capable of giving rise to waste “heat” when absorbed in the proper medium; but THERMAL RADIATION is a special kind of EM radiation which is produced entirely because of the mechanical oscillatory modes of ordinary materials, and is dependent on the Temperature for its characteristic Spectral envelope.
That shouldn’t be all that hard for anyone with a smattering of understanding of Physics to grasp, the general concepts of; and there is plenty of literature to support it.
In any case, I’ve about exhausted the extent of MY knowledge of these subjects; so further input from me would just be raising the entropy of the Universe.
George
Ira: “As I said, you may be right that hot N2, even when it is injected into a room-temp container of N2 will not emit photons as it cools off.”
The cooling N2 will certainly emit photons, but those photons will fall within the emission spectrum of N2. As I stated in a later comment, microwaves and radio waves are photons too. If the N2 is REALLY hot it emits a purplish blue light. They are all wavelengths of light.
Dominic: “Are you trying to use DECREASING energy states via reflections to account for what you will ‘see’ as a continuous spectrum?”
Correct, because the photons will lose energy on reflection.
“A continuous spectrum that includes wavelengths of shorter length (thus HIGHER energy states) than those possible by ‘supposed’ published N2 absorption spectra at a given temperature? Thus, the assumed equivalent emission spectra at a given temperature?”
Is there some emission spectrum for N2 that claims N2 cannot emit higher frequencies at higher temperatures (such as purplish blue light)? The plot of wavelengths emitted for a given temperature is a curve. Not a bell curve, but a similar concept – a big average near the center with decreasing frequencies in both directions. At a given temperature will be rare higher energy emissions, and these emission will fall within the emission spectrum.
Are you proposing that I can make a lead box, poke a hole in it, and get new emissions of x-rays? Lead doesn’t transmit x-rays, so any emitted within the box will be absorbed or reflected. Just take a lead box, poke a few holes in the side and BAM! – x-ray machine?
Or I could take a hollow cylinder of coal, poke a mesh of tiny holes at one end and BAM! – visible light comes pouring out, just by holding the cylinder in my warm hand? Of course not. We both know that for visible light to pour out, that coal cylinder needs to be heated until it is glowing hot, right?
“Because, if you isothermally heat that ‘all N2′ cavity up, above outside ambient temperature, the emitted radiation from the pinhole will follow near perfect BB radiation.”
The 0% transmissive cavity will follow BB radiation at or below ambient temperature as well. Unless you are at absolute zero the cavity is “heated up”. The lower the temperature of the cavity, the lower the average wavelength of light emitted (the center of the probability curve shifts). Both the size of your box and the size of the hole limits the wavelengths (you won’t detect radio waves coming out of a microscopic hole, nor can you fit a radio wave into a microscopic box).
To Myrrh, regarding the notion that lower frequency (higher energy) wavelengths can’t heat the earth because they are all “reflective”…
Does the earth beneath your feet look like a mirror image of the visible sky above? Look down at your feet at night – doesn’t look like any sunlight is making it through, does it? What is neither reflected nor transmitted is absorbed.
George E. Smith : “ANY EM radiation of ANY wavelength can be converted to “heat”; BUT is NOT of itself “heat”.
Too true, and perhaps I can make the point to others with an example…
What is the temperature of the vacuum of space near the earth? Pretty cold, right? But how could that be, with all of the EM radiation flowing through it?! Temperature (heat) is a property of matter, a measure of momentum. If there is no moving matter we do not record it as heat, no matter how much radiation is flowing through. Radiation is not measured as heat until matter gets in the way.
Phil. says:
March 7, 2011 at 5:01 am
Amazing, a century of science completely ignored, there should be a warning attached to this nonsense.
Nope, what we have here is half a century of RealScience deliberately perverted to fit an agenda. That’s why you’re unable to grasp what I’m saying, you’ve been educated to believe impossible things about our real physical world. You no longer understand it or the knowledge we have gained through RealScience until AgendaScience created AGW, otherwise you wouldn’t think what I’m saying is nonsense.
Phil. Take a look at the NASA page I posted and its new version. The first, it will stay up until 31st May before being automatically re-directed, has a bar graphic of the Infrared wavelength. Look at it very, very carefully. Now go to the new page and look at the one they have there. Do you notice any difference?
The first page comes from an educational outreach to children, untouched by pcAGWScience mangling and distortion and plain downright lies. The second page has the characteristic marks of AGWScience tampering to fit an agenda.
When you spot the difference, think about it. The old page is standard classic Science well known through the last century, it’s what I’m saying here. The second page no longer teaches this, and to boot, it has tampered with real science fact.
NASA has been compromised, it is aiding and abetting in creation of a generation now and future generations of ignorant kids. Real Science doesn’t have to lie and fake data … In the end, those who think to fool people are the real losers, a waste of life.
Tim Folkerts says:
March 7, 2011 at 8:37 am
I think you (and perhaps the rest of us too) are too caught up in labels.
What the rest of you are caught up in, I have no idea.., but I am concentrating on the principles here, which some are finding difficult to grasp distracted as it appears they are from either taking AGWScience at face value or by getting bogged down in the minutia of what they think the science is saying heat is, whether right or wrong is irrelevant here, and missing the big picture. Which picture I am saying has to grasped in the principles to be able to understand this, and especially to see where AGWScience has perverted it by its misappropriation of RealScience terms and conditions, out of context etc. The labels I’m using are common English meanings.
Glass tends to absorb Near IR, but not visible or thermal IR.
? If you mean that as it’s written, there is no “visible IR”.
If you saying ‘glass tends to absorb Near IR, but not Visible or Thermal IR’, then so much for the “greenhouse” which supposedly let’s in Visible but not Thermal IR..
Anyway, you give a bunch of figures, some of which it would take too long for me to check, but some anyway irrelevant to what I’m trying to present here, and some such as percentage of Visible I’ve already disputed above, so simply repeating it isn’t getting us any further.
Your paper experiment, does it mean that? You’ve just said that flat white absorbs IR better than flat black. As the Visible isn’t a heat energy, it isn’t adding any heat to the black paper so reflecting it away by using white paper isn’t making any difference, it’s not adding heat either way.
Domenic says:
March 7, 2011 at 9:37 am
You are pointing towards some interesting areas, BUT your language terms, choice of words, and their traditional accepted meaning by scientists, is a bit muddled.
See above to Tim.
Reflection is a property of Light, that’s how it is described by SCIENCE. Light reflects off surfaces, Heat penetrates. Light and Heat are the Scientific shorthand which perfectly describe the PRINCIPLE difference in properties between the two. Knowing this one can then extrapolate correctly in considering interactions between the various wavelengths and matter. I really do think this is the key to solving the problem of misunderstanding here, if this simple principle of difference is understood the rest does fall into place.
Now, theoretically, when a plant absorbs very certain wavelengths of energy, it need not produce any ‘heat’. Thus there is no increase in temperature whatsoever to detect, as a byproduct of the interaction. So, those wavelengths are not re-radiated back into the atmosphere contributing to any ‘greenhouse effect’.
That’s not the second sentence I’d have written.. 🙂
I would have said something along the lines, because plants absorb red and blue light which are Light energies not Heat energies, they do not add heat to the plant absorbing them…
And until someone goes out and measures them IN NATURE (or, in other words, observes their ‘dance’ in nature) rather than in a lab, it will completely escape them.
Well, I’m not knocking lab work. From this for example we know that what the plants reflect back is green light, which is why we see them as green. Just as white paper reflects back the Visible spectrum, and black paper absorbs all the Visible so we see it as black. What I do object to is the way AGW uses Science information gained in and out of the lab, out of context. Laws which apply only to closed systems, laws which apply only to ideal gases, which are purely imaginary, and like here with Ira’s diagram, simply reversing the attribution of properties has caused this incredible confusion which it is very difficult to correct.
We already have that that basic information from Nature, and where we do, we don’t have to keep going out to re-invent the wheel. RealScience knows the difference between the wavelengths and how plants use them. The very real problem here is that AGWScience rejects all these real examples from Nature, it has given up on observation (*) and so the best we can do is to remind AGW’s that this real science exists which does already understand so much of the physical reality we’re in.
(*) Which reminds me of Keeling. This rejection of observation of Nature was going on then, AGW has now worked this up into an art form.. Hold on, I’ll look for the article –
http://carbon-budget.geologist-1011.net/
Scroll down to 3.0 – I think you’ll find it interesting.
It’s not so much lab work v nature, but imaginary modelling without taking actual lab work or observation from nature into this imagination. They’re writing science fiction in their preposterous claims for Solar energy and CO2 because these claims are not grounded in reality. And of course from that they’re willing and conniving to deliberately manipulate data to ‘prove’ their fiction, and that’s simply not what science is about. That’s our loss.
Someone said recently in a discussion here, that the Piltdown Man hoax set back scientific understanding for yonks, it was a long time before the confusion that it created was sorted and real science allowed to move on again. It couldn’t do this until it became just as generally known it was a hoax. What we have here is a strange variation on that. The science pre AGW knew all these things, it has in some areas continued to work and research and innovate because it was known, IR cameras and now into healing (which I think is an incredibly important finding), and AGW has reversed this and is teaching this corruption of science as if it is real. This has become so much more widespread than the Piltdown Man hoax, it affects everyone because this corrupt science has already got into our education system. It does seem like a monumental task to get back on track from that..
Hi Steve,
((Is there some emission spectrum for N2 that claims N2 cannot emit higher frequencies at higher temperatures (such as purplish blue light)?))
Phil, with his absorption charts, thinks N2 can only emit at discreet wavelengths. Under certain conditions, N2 can indeed emit as if it is a near blackbody.
((The plot of wavelengths emitted for a given temperature is a curve. Not a bell curve, but a similar concept – a big average near the center with decreasing frequencies in both directions. At a given temperature will be rare higher energy emissions, and these emission will fall within the emission spectrum.))
Yes, if I understand you correctly, you are saying it is possible under a probabilistic quantum theory model. In this situation, the environment (the cavity) changes the probabilities. It is not random.
((Are you proposing that I can make a lead box, poke a hole in it, and get new emissions of x-rays? Lead doesn’t transmit x-rays, so any emitted within the box will be absorbed or reflected. Just take a lead box, poke a few holes in the side and BAM! – x-ray machine?))
No. You won’t get x rays out of it. It can only emit up to close to blackbody radiation at any given temperature. It cannot exceed it.
((The 0% transmissive cavity will follow BB radiation at or below ambient temperature as well.))
It will do so whether the outside ambient is above, at, or below the cavity temperature. It is basically independent of it. That was my point.
((Both the size of your box and the size of the hole limits the wavelengths (you won’t detect radio waves coming out of a microscopic hole, nor can you fit a radio wave into a microscopic box).))
Hmm. Not sure. Interesting question. Atoms and molecules, when supercooled, approaching absolute zero, should, according to blackbody theory, only be able to emit long waves, hence radio waves. So, I don’t think it is a matter of fitting a radio wave into a microscopic box.
George E. Smith says:
March 7, 2011 at 1:49 pm
But what Phil spent a lot of time and energy pointing out was that N2 and O2, lacking a dipole moment in the isolated molecules are NOT IR active, in the molecular band spectra sense; although perfectly amenable to collision induced thermal emissions; which evidently are still low intensity, because of the molecular sparseness, and low energies at ordinary atmospheric conditions.
Most of what you said is right on the money.
When you say “… amenable to collision induced thermal emissions; which evidently are still low intensity, because of the molecular sparseness …” must be addressing CO2 for N2’s concentration is not sparse of course.
It is your emphasis “NOT” and Phil’s emphasis of “no” that I have been complaining about. CO2 does not have a permanent dipole moment either. We are discussing the atmosphere here, not isolated species of molecules and it is the collision interactions of the different molecules that make the real spectrum of the entire atmosphere much more complex.
http://www.cas.usf.edu/lidarlab/hitran_pc.html
As to the size of this effect being small, I have agreed multiple times above. Without more words just explain to us here why HITRAN shows IR lines for N2 at about 3.2 to 5 µm and why you and Phil insist they do not even exist.
Here’s a paper that combines radiational absorption of CO2 in situ with its heat capacity, etc relative to the whole atomosphere. Interesting approach.
http://www.biocab.org/ECO2.pdf
His conclusion? Adding CO2 under current conditions actually decreases troposphere temperature.
And that is exactly what the temperature record from 1957 to now says is going on in the Antarctic South Pole area.
Wayne, I think everyone is basically a scientist, we like to know how things work, “why”? is a favourite question from childhood on! This site certainly has a plethora of good science thinkers, and links to others. I haven’t followed anything by Miskolczi -http://www.friendsofscience.org/assets/documents/E&E_21_4_2010_08-miskolczi.pdf – it has far too much maths language for it to be an easy read for me…
..can you precis it in English..?
Tim Folkerts says:
March 7, 2011 at 10:23 am
But the very site he links to says “Ala. Biologists have found that cells exposed to near-infrared light from EEDs, which is energy just outside the visible range, grow 150 to 200 percent faster than cell not stimulated by such light.”
The LED IR emitters that are being touted as heating tissues typically operate in the 0.8 – 1.0 um near IR part of the spectrum – the very part of the spectrum that is “reflective” and “cannot heat things” [which Myrrh said].
I can’t find that particular one, can you link to it directly please?
However, as you’ve written this it is you who are calling “stimulated” heat energy.
There are two things here, firstly that Near IR is Reflective, but that doesn’t mean it doesn’t penetrate at all.. I’ve already gone through this, that it penetrates more than Visible and UV penetrates less than Visible. But, Reflective energies are not Heat energies, so what Near IR does is not alter the heat of the tissue it is penetrating (just as a plant doesn’t get heated from Visible light), the energy state of IR is STIMULATING cells etc.
As long as you continue to associate high energy reflective light with heat production you’re going to misunderstand what’s being said, and so the method by which Near IR works in healing.
High energy short wave reflective light does not penetrate because most of it reflected away, these are not hot, you cannot feel them. You cannot feel UV until it is burning you. UV does not penetrate further than the first layer of skin, skin has three layers, that’s how penetrating it is. It is the very high energy of UV which burns. Think of high speed electric drill.. Visible light does not burn, it is BENIGN, its energy state is much less than UV. Near IR does not burn either, at a lower energy state even than Visible. It is not heat energy from Near IR, because it doesn’t have it at these higher energy wavelengths which are being used in these kinds of therapies, but the actual energy of the wavelength which is affecting healing. Thermal IR, the longer wavelengths, converts to heat in the body, so used for heat therapies, cooking, etc.
You’re still mixing up the difference between high and low energy wavelengths by associating high energy states with production of heat.
And George and Steve and Tim et al
All energy can produce heat, but not all energies are Heat energies.
How far does Light penetrate the ocean? http://www.funtrivia.com/askft/Question44602.html
1) only 73% of the surface light reaches a depth of 1 centimeter (less than a half inch)
2) only 44.5% of the surface light reaches a depth of 1 meter (3.3 feet)
3) only 22.2% of the surface light reaches a depth of 10 meters (33 feet)
4) only 0.53% of the the surface light reaches a deptth of 100 meters (330 feet)
5)Only 0.0062% of the surface light reaches a depth of 200 meters
according t: geosun1.sjsu.edu/~dreed/105/exped6/13.html
Which link I haven’t checked out.
A NOAA page says: “Such a miniscule amount of light penetrates beyond a depth of 200 meters that photosynthesis is no longer possible.” http://oceanservice.noaa.gov/facts/light_travel.html
Which explains it better? Which gives you a better picture, better understanding of how far light penetrates in the ocean?
Like the new NASA page on IR which will no longer give such a real vivid description of what IR is, what we feel as heat from the Sun, and what Near IR is, not hot, but avoids stating this, so this NOAA page doesn’t actually give you the information which clarifies, it obfuscates.
Nearly 3/4 of surface light doesn’t even get further than the first 1 centimeter.
Why? Light is reflective and most gets reflected away by water, Thermal energies, longer wave IR are not stopped by water. If you’ve ever been scuba diving in warm dark ocean …
There’s one other point I’d like to make again here.
There’s also a lot of misinformation about where Reflective IR ends and Thermal begins. AGW is very keen on stretching Thermal as far away as possible from Near in order to include it in its ‘Solar energy budget’ which includes Near IR’ . (which is a hint for the difference in the NASA IR bars graphic).
http://www.cartage.org/lb/en/themes/arts/photography/fieldskinds/scientificph/medscient/infraredphoto/reflectinfrar/reflectinfrar.htm
“Today the infrared spectrum is recognised as extending from about 700nm up to wavelengths of about 1mm where it overlaps with radiowaves. Photography is normally confined to the near infrared – 700-900 nm. A great deal of confusion continues to arise concerning infrared photography and the measurement of infrared energy in the form of heat. This confusion often leads to futile attempts to detect thermal patterns through the use of infrared photography in cases where the technique does not apply. Contrary to what many people believe, the infrared record in a photograph is not a measure of ambient temperature variation – it is a record of the amount of near infrared radiation reflected or transmitted by the subject. Thermal photography cannot be done with infrared sensitive film. Far infrared (approximately 2-15mu).”
So, where does Reflective IR which does not convert to heat end and Thermal begin?
What does that mean in all those ‘greenhouses are opaque to thermal IR’ spiels?
Anyway, I think I’ve answered the gist of the questions to me, if I’ve missed anything of yours let me know.
Myrrh,
I will give you the same request that I gave earlier — define precisely what you mean by “heat” (and now I will add “light”). (I guarantee your definition will be different from mine, and different definitions in the 2md law discussion earlier). While you are at it, your definition of “thermal IR” would be helpful. You seem to throw the terms around as if they have absolute meanings with absolute properties. Perhaps if you could tell us exactly what you mean by these terms, then would could all have a productive discussion rather than talking past each other.
You say “light is reflective” and “thermal IR is absorptive” almost as if these are absolutes; as if they are laws of nature. Are you claiming that light is 100% reflective and cannot heat objects and that this is a universal property of light independent of the matter it is interacting with? Are you claiming that thermal IR is 100% absorbed and that this is a universal property of thermal IR independent of the matter it is interacting with? Your shouts above give me this distinct impression.
“… and some such as percentage of Visible I’ve already disputed above, so simply repeating it isn’t getting us any further.”
Simply denying it isn’t getting us any farther, either. Multiple sources suggest that the energy from BB radiation at ~5700 K (eg from the sun) will be
~10 UV,
~40% visible,
~ 45% IR-A & IR-B (0.7 – 3 um), and
~5% “thermal IR” (3 um and longer).
For a BB @3100 K (eg light bulb filament) , the numbers become
~0 UV,
~10% visible,
~ 80% IR-A & IR-B (0.7 – 3 um), and
~10% “thermal IR” (3 um and longer).
For a BB at 1300 K (eg heat lamp filament)
~0 UV,
~0% visible,
~ 50% IR-A & IR-B (0.7 – 3 um), and
~50% “thermal IR” (3 um and longer).
Do you still dispute these? If so, please provide better numbers. (These specifically are based on numbers from wikipedia)
Finally — you say “Your paper experiment, does it mean that? You’ve just said that flat white absorbs IR better than flat black. As the Visible isn’t a heat energy, it isn’t adding any heat to the black paper so reflecting it away by using white paper isn’t making any difference, it’s not adding heat either way.”
Scratching my head …. Black paper doesn’t get heated by the sun more than white paper? Black cars don’t get hotter than white cars? Black clothes aren’t warmer than white clothes on a sunny day? Is this truly what you mean when you say “reflecting it away” with light colored objects “isn’t making any difference”?
Myrrh,
It looks like you posted some comments while I was drafting my comments, and you addressed at least some of my concerns. You seem to acknowledge that all EM radiation can reflect or absorb, which sounds much different that your earlier posts.
Let me address one more issue you just brought up and then I need to get back to my “paying job” for a while.
You say :
“Nearly 3/4 of surface light doesn’t even get further than the first 1 centimeter.
Why? Light is reflective and most gets reflected away by water, Thermal energies, longer wave IR are not stopped by water. If you’ve ever been scuba diving in warm dark ocean … ”
There are three significant mistakes here …
1) Nearly 3/4 of the light DOES get further than 1 cm. You need to get 10 m down before 3/4 DOESN’T make it .
2) Very little visible light is reflected. If 73% gets 1 cm deep, then no more than 27% could have been reflected, which is definitely not “most”.
3) Most significantly, the “penetrating” thermal IR gets stopped within 0.1 millimeter of the surface. It penetrates far shorter distances into water than the “non-penetrating” visible light. http://alignment.hep.brandeis.edu/Electronics/A2053/HTML/Water_Absorption.gif
Domenic says:
March 7, 2011 at 5:44 pm
Hi Steve,
((Is there some emission spectrum for N2 that claims N2 cannot emit higher frequencies at higher temperatures (such as purplish blue light)?))
That’s the emission you get in a Nitrogen discharge tube as a result of electronic transitions (both singlet and triplet).
Phil, with his absorption charts, thinks N2 can only emit at discreet wavelengths. Under certain conditions, N2 can indeed emit as if it is a near blackbody.
OK, those conditions are?
Myrrh says:
March 7, 2011 at 7:19 pm
Nearly 3/4 of surface light doesn’t even get further than the first 1 centimeter.
Why? Light is reflective and most gets reflected away by water, Thermal energies, longer wave IR are not stopped by water. If you’ve ever been scuba diving in warm dark ocean …
I assume this is a joke since anyone who’s scuba dived knows that the light that penetrates furthest are the shortest wavelengths (UV, Blue), whereas the IR hardly penetrates at all.
http://www.btinternet.com/~martin.chaplin/images/watopt.gif
wayne says:
March 7, 2011 at 6:19 pm
Without more words just explain to us here why HITRAN shows IR lines for N2 at about 3.2 to 5 µm and why you and Phil insist they do not even exist.
You mean the ones that I posted the spectra of here several times? The ones that are about 100,000,000 times weaker than CO2?
Domenic: “Phil, with his absorption charts, thinks N2 can only emit at discreet wavelengths. Under certain conditions, N2 can indeed emit as if it is a near blackbody.”
Phil is correct, N2 does only emit at discreet wavelengths. At higher temperatures, one of those wavelengths is purplish blue light. When would it emit as if it is a near blackbody? Point me to an experiment. If you say “when we theoretically use it to make a 0% transmissive cavity”… No! The cavity contains both emitted and reflected light. Strip away five of the walls, and when measuring the emission of the remaining wall all you will detect are the discreet wavelengths within the wall’s emission spectrum.
“((Both the size of your box and the size of the hole limits the wavelengths (you won’t detect radio waves coming out of a microscopic hole, nor can you fit a radio wave into a microscopic box).))… Hmm. Not sure. Interesting question.”
That’s relatively basic physics – the size of the aperture limits the wavelength of light that can pass through it. That’s why you can be driving through a tunnel and the AM stations go to complete static while the FM stations don’t – AM uses longer wavelengths. AM waves are so large that they can’t even penetrate down into narrow valleys. Getting into advanced physics, the conductivity of the aperture walls (metals having many available free electrons) and the ratio of the mesh thickness to aperture size come into play. http://www.madsci.org/posts/archives/2002-03/1015162213.Eg.r.html
“((The plot of wavelengths emitted for a given temperature is a curve. Not a bell curve, but a similar concept – a big average near the center with decreasing frequencies in both directions. At a given temperature will be rare higher energy emissions, and these emission will fall within the emission spectrum….Yes, if I understand you correctly, you are saying it is possible under a probabilistic quantum theory model. In this situation, the environment (the cavity) changes the probabilities. It is not random.”
The probability that a certain wavelength within the emission spectrum of the wall material will be emitted is dependent on the wall’s temperature (not random). The cavity doesn’t change those probabilities. The cavity creates a continuous band of reflected wavelengths between the emitted wavelengths.
Maybe these videos will help?
http://wn.com/emission_spectra
Myrrh says: “Wayne, I think everyone is basically a scientist, we like to know how things work, “why”? is a favourite question from childhood on!”
OK, Mr. Scientist, here’s an experiment for you.
Hypothesis = Visible light doesn’t penetrate the entire epidermis because it is “Reflective”. Experiment = Take an ordinary pen light and go into a dark bathroom. Stick the light in your mouth, or up your nose. Does the light shine through? Go out on a sunny day and look at the backs of your wrists. Do you see your veins, just below the epidermis? Question = If these results are not due to visible light penetrating the skin, then what?
By the way, “why?” is a question for subjects such as philosophy and theology (also very interesting!). Science asks “how?”.
Myrrh says:
March 7, 2011 at 7:19 pm
Wayne, I think everyone is basically a scientist, we like to know how things work, “why”? is a favourite question from childhood on! This site certainly has a plethora of good science thinkers, and links to others. I haven’t followed anything by Miskolczi -http://www.friendsofscience.org/assets/documents/E&E_21_4_2010_08-miskolczi.pdf – it has far too much maths language for it to be an easy read for me…
..can you precis it in English..?
—-
Hi Myrrh. Scientist at the heart, that is what I like in any person, the ability to question.
On Miskolczi, that’s a tall order, but I know exactly where you are. I too opened up his paper and after a couple of hours I was totally confused. I could follow his general methodology but the parameters were all different that what I had become familiar with from IPCC and Trenberth-Keihl and even his approach was different in the budget. But, two months, on and off, after drawing arrows on his chart to match the equations it finally became clear. If I would have stumbled onto Dr. Miklos Zagoni’s summary paper it would have been much easier (see at bottom).
Here’s some overviews:
http://pathstoknowledge.wordpress.com/2010/01/13/ferenc-miskolczi%E2%80%99s-saturated-greenhouse-effect-theory-c02-cannot-cause-any-more-global-warming/
http://www.blog.speculist.com/archives/001668.html
http://www.dailytech.com/Researcher+Basic+Greenhouse+Equations+Totally+Wrong/article10973.htm
http://www.examiner.com/civil-rights-in-portland/hungarian-physicist-dr-ferenc-miskolczi-proves-co2-emissions-irrelevant-earth-s-climate
In his paper, the thrust of his work was to plot the changes in the radiative window size (optical thickness or tau) over the sixty years since 1948 since this data has been gathered daily all over the world over this period. He found it to be so close to the same every year that when plotted all dots fall basically on top of each other at 1.867xxx or a proportion exp(-1.867) = 15.46%. If 390 W/m2 is the surface emission the window would be 390*0.1546 = ~60 W/m2 but never changing, even as co2 has increased over this same period.
He has published more than once but in this particular paper below:
http://www.friendsofscience.org/assets/documents/E&E_21_4_2010_08-miskolczi.pdf
view Figure 7. That is the gist of his work. The dark dot is 60 years of the optical thickness plotted when CO2 has been increasing.
He used two different sets of data to get these results of tau (optical thickness, IR of course):
1948-1997: Temp=288.81 K, H2O=2.6168 prcm, tau=1.867596
1959-2008: Temp=288.94 K, H2O=2.6106 prcm, tau=1.867976
The rest of the paper shows some very curious relationship he found between his parameters and some of the key relations were matching previously published factors calculated by other methods verifying this result.
Well, to go any deeper would require a paper but Dr. Zagoni has already done that & better that I could:
http://nige.files.wordpress.com/2011/02/the-saturated-greenhouse-effect-theory-of-ferenc-miskolczi.pdf
Interesting stuff, get’s into Mars atmosphere also (why was Mars warming parallel to the slight warming on Earth, still a big question).
Steve wrote:
((No! The cavity contains both emitted and reflected light.))
Then where does the reflected light come from?
There is only N2 in the cavity.
((Strip away five of the walls, and when measuring the emission of the remaining wall all you will detect are the discreet wavelengths within the wall’s emission spectrum.))
The whole point here is ‘cavity radiation’ unique properties phenomena. If you change the environment by removing some of the walls, the observed properties change.
That has been my only theme here.
Some people get it. And some don’t.
Some believe in absolute properties of a given bit of matter.
I don’t.
Because all the evidence points away from absolute properties.
The ‘Heisenberg uncertainty principle’ reigns, even in radiational heat tranfer physics.
I will leave it at that.
@ur momisugly Ira
I think that the second of the points I made about affects of additional CO2 is the way to present “the greenhouse effect” (“With more CO2, the effective “Top of Atmosphere” will be higher, which means cooler, which means less outgoing IR. To return to equilibrium, the top layer would have to warm up. This would in turn warm all the layers below.)”
Among other advantages, it also describes the greenhouse effect on Venus and Mars as well. Basically, GHG’s & radiation balance determine the TOA (the effective top of atmosphere for IR radiation emission) temperature, while the lapse rate then determines the surface temperature.
* At TOA, Venus will be a little warmer than earth, and Mars will be a little cooler due to distances from the sun.
* The increase in temperature from TOA to surface will be larger on Venus than earth (because its atmosphere is so much thicker). On Mars, the atmosphere is so thin that the TOA will be quite close to the surface. This mean very little lapse-rate-driven warming from TOA to surface.
Combined, Venus should be much warmer than earth and Mars should be cooler, even though both have much higher concentrations of GHG’s than earth. (the details would take more in-depth calculations of things like lapse rates in different atmospheres and where exactly the TOA is on the three planets, but the magnitudes are clearly correct).
Tim Folkerts says:
March 8, 2011 at 10:33 am
@ur momisugly Ira
I think that the second of the points I made about affects of additional CO2 is the way to present “the greenhouse effect” (“With more CO2, the effective “Top of Atmosphere” will be higher, which means cooler, which means less outgoing IR. To return to equilibrium, the top layer would have to warm up. This would in turn warm all the layers below.)”
Among other advantages, it also describes the greenhouse effect on Venus and Mars as well. Basically, GHG’s & radiation balance determine the TOA (the effective top of atmosphere for IR radiation emission) temperature, while the lapse rate then determines the surface temperature.
* At TOA, Venus will be a little warmer than earth, and Mars will be a little cooler due to distances from the sun.
* The increase in temperature from TOA to surface will be larger on Venus than earth (because its atmosphere is so much thicker). On Mars, the atmosphere is so thin that the TOA will be quite close to the surface. This mean very little lapse-rate-driven warming from TOA to surface.
Combined, Venus should be much warmer than earth and Mars should be cooler, even though both have much higher concentrations of GHG’s than earth. (the details would take more in-depth calculations of things like lapse rates in different atmospheres and where exactly the TOA is on the three planets, but the magnitudes are clearly correct).
On Mars the absorption by CO2 will be much less effective because of the much lesser broadening on the lines on Mars.
http://i302.photobucket.com/albums/nn107/Sprintstar400/Mars-Earth.gif
Domenic “Then where does the reflected light come from? There is only N2 in the cavity…The whole point here is ‘cavity radiation’ unique properties phenomena. If you change the environment by removing some of the walls, the observed properties change.”
No, folding a sheet of a material into a new shape does not give the material new atomic properties. The walls emit the same wavelengths when presented as a single wall or enclosed cavity. Every reflected wavelength originates as an emitted wavelength, which loses energy with each subsequent reflection.
Do you want to detect all of those reflected wavelengths coming off of a single wall, outside of a cavity? No problem. Simply direct an appropriate light source at your wall and view it from the appropriate angle. The reflected light is not a “new property” that only occurs within the cavity. It is a constant property that can observed at any time, without a cavity – you just need to be looking for it.
In the cavity, the walls serve as a light source for each other. With at least one perpendicular and one parallel wall, you can observe every angle of incidence. Since the box is defined as 0% transmissive for the range of wavelengths investigated, by definition they can’t get out of the box. So they must continue to bounce around, losing energy with each reflection, until they are absorbed (which only occurs within the wall’s defined absorption spectrum). The wall’s ability to emit, reflect, absorb or transmit any particular wavelength hasn’t changed one iota by shaping a box out of the wall.
“”””” wayne says:
March 7, 2011 at 6:19 pm
George E. Smith says:
March 7, 2011 at 1:49 pm
But what Phil spent a lot of time and energy pointing out was that N2 and O2, lacking a dipole moment in the isolated molecules are NOT IR active, in the molecular band spectra sense; although perfectly amenable to collision induced thermal emissions; which evidently are still low intensity, because of the molecular sparseness, and low energies at ordinary atmospheric conditions.
Most of what you said is right on the money.
When you say “… amenable to collision induced thermal emissions; which evidently are still low intensity, because of the molecular sparseness …” must be addressing CO2 for N2’s concentration is not sparse of course. “””””
I did NOT mention CO2; therefore I was NOT addressing CO2 but Nitrogen (N2). Earth’s atmosphere is mostly empty space; the tiny fraction of that space that is occupied by N2 molecules, is actually accounted for in the Van der Waals equation of state.
By anybody’s reckoning, compared to the 5.00 x 10^22 atoms per cc in the Silicon crystal, a total of about 6.023 x 10^23 total molecules in about 22.4 litres of atmosphere (at STP); of which about 78% are N2, would be considered sparse. Is it not the reason some people think gases cannot emit thermal continuum radiation.
As for CO2 having no dipole moment; that may be true for the usual O=C=O atomic configuration; but notice that Heisenberg’s Principle of Uncertainty would dictate, that if we know that the atoms are in those precise locations, we cannot know their momenta with any precision beyond the Heisenberg h/2pi, dx.dp product. So if the C were displaced axially from perfect symmetry, then a dipole moment would exist; and the same goes for any assymmetrical axial momentum for the three atoms, so any change would open the molecule to the 4.0 miron assymmetrical stretch mode which is THE strongest CO2 line, and any displacement or momentum out of the linear cofiguration, will open the moleculae to the 15 micron (667 cm^-1) LWIR line that is most active in earth atmosphere.
Nitrogen N2, evidently has amuch more symmetrical electron structure, than a lot of homodiatomic molecules, which is why it is so chemically inactive to the point where it almost bahaves like a noble gas (but not quite). So I can easily see (although not fully understand in detail) why N2 exhibits such low IR activity; and remeber what Phil is referring to with the Spectralcalc plots he cited, relate to resonance modes of oscillation of the N2 molecule, basically in isolation; which is the nature of most molecular spectral bands. That is a specific function of those molecular structures, as distinct from THERMAL continuum emissions, that are not mechanical resonances in the usual sense.
The 15 micron CO2 band is of course the well known degenerate bending mode, comprising two identical modes of oscillation at right angle to each other (and the molecular axis.) I guess that’s why it is called degenerate since there are two identical, and apparently indistinguishable modes at the same frequency.
I’m not a chemist so this stuff is not bright on my radar screen.
As for all the stuff about reflectance of light etc, and absorption in water; I have posted Reference Handbook information on this stuff so many times that I can’t imagine there is any visitor to WUWT, who has not seen that. I’m not in the habit of simply labelling stuff as rubbish; but it works well for Phil, so maybe I should simply say, rubbish to that completely unsupportable disinformation on water absorption and reflections. Reflection incidently is a property of materials, not of light; and arises naturally from Maxwell’s equations on EM waves encountering a material interface between two different media, that have different characteristic impedances, and/or velocity of wave propagation. It’s exactly the same phenomenon that leads to reflections on transmission lines, when an impedance dicontinuity is encountered. For light encountering a material interface, the Fresnel Polarized reflection formulae apply, which can be found in any good Optics text book; try Born and Wolfe, which is a not half bad standard Optical Text. (“Principles of Optics.”)
Sorry, can’t get back to this until the weekend.
For George E. Smith, some info from someone with a BS in biochem: Why CO2 is rarely symmetrical at any given instant…
The four electrons that Carbon has for bonding form a tetrahedron. Oxygen, having a powerful affinity for these electrons, bends the bond angles. Take your index fingers and thumbs together and make an “OK” sign. Now take the two rings formed in each hand and bring them together. You should be able to bring this configuration up to your eyes and look through it, like a pair of glasses.
Only when the rings are like this, in the same plane, is the configuration perfectly symmetrical. Now twist one ring so that they are perpendicular to each other. Following your fingers away from the point of contact, you can follow one index finger away from you, the thumb from the same hand towards you, the other index finger up, and it’s corresponding thumb down. This is actually closer to carbon’s preferred configuration of a tetrahedron. The orbital fields repel each other, and you can see that in this perpendicular configuration the orbitals are farther apart than when the rings are in the same plane. This is the more stable configuration of CO2. In reality, the four covalent bonds are like two rings, touching, with both rings spinning about the point of contact. The higher the temperature, the more spinning.
It’s fairly easy to imagine if you’ve ever had to make CO2 with the standard ball & stick chemistry set.
http://labspace.open.ac.uk/file.php/4079/S154_1_019i.jpg
Sorry guys, gotta call it quits on this thread (Myrrh, I’ll watch for any questions you might have on Miskolczi’s paper).
Ira, before I leave here is a cute little game in imagination that my grandkid helped me build and play.
We had a whole day to kill so I decided to teach my grandkids something about the climate by creating a new game, ‘Atmosphere’.
I have a 9’ x 12’ throw rug and also a huge jar of pennies and nickels. We labeled one 9’ edge ‘Surface’ and the opposite ‘Space’. The pennies are water molecules, the nickels carbon dioxide, many more pennies that nickels when near ‘surface’. They helped me arrange these coins randomly spaced but very densely spaced near the ‘surface’ edge and smoothly getting farther apart as we went toward the ‘space’ edge. Near ‘space’ they were a foot apart and near the ‘surface’ edge they nearly touched each other, about a pennies worth of gap. Pennies became very rare near the ‘space’ edge.
We borrowed a spinner from another game that had 12 divisions (kind of rough integration). Six consecutive pie slices were then ‘down’ and the opposite were ‘up’ and the spinner always had to stay oriented with the game board (rug) where the six ‘down’ slices we pointed toward ‘surface’, the other pointing toward ‘space’.
The object of the game was to start three feet from the surface edge (500 mb) and the first one getting to the surface won. Each person took a turn to spin the spinner and you had to move in the direction of the pie slice where the arrow landed and stop at the first and closest coin possibly encountered. We used a yardstick to help judge this.
You got one point for landing on a penny, five for landing on a nickel.
My grandson won the very first game (beginners luck) after spinning an amazing sequence of downs in a row. Nine downs with only one up. But after two hours of playing that darn game many times no one ever won again. This game was a sure loser.
Didn’t take them long to figure out what was the problem with this boring game. It was the spacing between the coins getting farther and farther apart (density) as you went from the ‘surface’ toward ‘space’. You could roll a long sequence of up, down, up, down, down, up, up, down but somehow you were always making your way toward ‘space’ where you were then out. And if you ever hit a sequence of up, up, up, down, up, you were a goner.
At that point I told them that they may have lost all but one game, but they now knew more about this real worlds atmospheric physics and how radiation really moves within than the majority of the best climatologist in this entire world. (BIG SMILES!) They each got a graduation certificate from “Grandpa’s Climatology University” and at age 9 and 12, that ain’t bad!
Now just try to pull this “back radiation” mind-trip on them. They are now true skeptics and might one day be great proper climatologists, who knows.
Later all.