Questions.....RE: The Greenhouse Effect

[Crick]

So, Same Shit, are you saying there is no greenhouse effect?

 

[Olde Europe]

the theoretical maximum temperature of any object being warmed by the Sun is the temperature of the Sun.

Seemingly, if I am following your reasoning correctly, it makes no difference if that object is 100 meters, 100 million kilometers, or a billion light years away. If that's the case, and the earth sure receives energy from from a few billion stars every second and from all directions, and is surrounded and perfectly isolated by a vacuum, why aren't we at 5000°C surface temperature?

 

[Olde Europe]

I think Crick has a point about reading too much into SSDD. SSDD isn't that smart. I can see your point. SSDD said,,

And again...if you build a model that is flawed when it is stripped down to its bones...no amount of fleshing out is going to make it a valid model...​

But that was 355 posts into this thread, and I see that as an afterthought.

SSDD as a premise for the sake of argument, said he would allow the idea of back-radiation. Then he backs out of that in post 345. I still think he has no point in this thread that is any different than his other rantings. Maybe he thought it was a "gotcha" moment for the scientists, but he was the one that suffered the "gotcha".

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I've moved that text of yours over to the appropriate thread, since here's where that "the model is flawed" action originated, hoping you won't mind.

I've made up my mind about SSDD, and he isn't debating, or rather, he's behaving as a parasite to debate, taking advantage of features of debate while contributing nothing but slander, smear, falsehoods, and pseudo-reasoning. That said, there is nothing left to do other than pointing out ignorance, or spurious reasoning, as the case may be, so as to have the record corrected.

What's the benefit? Of course, the simplified model (with GHG atmosphere) deviates in many respects from reality, as it captures just one or two basic mechanisms. The difference between "adding more complexity" to save that basic model (along with its flaws) or the ones built on it, and embedding that basic mechanism (back radiation) into a more complex model (closer to reality), should be immediately obvious by now, and the flaws of the simplistic model are not to be found in the more complex ones. That's what I thought was worth pointing out, SSDD's crowing notwithstanding.

 

[Wuwei]

I've moved that text of yours over to the appropriate thread, since here's where that "the model is flawed" action originated, hoping you won't mind.

Don't mind. He cross-posted the same thing in 3 different threads.

I've made up my mind about SSDD, and he isn't debating, or rather, he's behaving as a parasite to debate, taking advantage of features of debate while contributing nothing but slander, smear, falsehoods, and pseudo-reasoning. That said, there is nothing left to do other than pointing out ignorance, or spurious reasoning, as the case may be, so as to have the record corrected.

Yes, I think there is no question that SSDD is just a troll. I know that I along with others have been guilty of feeding the troll. The problem is that he along with his admirers, are wallowing in invectives. The huge bulk of their intense rantings on the "stupidity" of those that don't agree with him may give the impression to others, less involved in the climate question, that he knows what he is talking about.

So, I think his intense ranting is not aimed at the more science savvy. His intended audience is his bootlicking minions and newcomers that may be on the fence about the climate issues.


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[jc456]

I think Crick has a point about reading too much into SSDD. SSDD isn't that smart. I can see your point. SSDD said,,

And again...if you build a model that is flawed when it is stripped down to its bones...no amount of fleshing out is going to make it a valid model...​

But that was 355 posts into this thread, and I see that as an afterthought.

SSDD as a premise for the sake of argument, said he would allow the idea of back-radiation. Then he backs out of that in post 345. I still think he has no point in this thread that is any different than his other rantings. Maybe he thought it was a "gotcha" moment for the scientists, but he was the one that suffered the "gotcha".

.

I've moved that text of yours over to the appropriate thread, since here's where that "the model is flawed" action originated, hoping you won't mind.

I've made up my mind about SSDD, and he isn't debating, or rather, he's behaving as a parasite to debate, taking advantage of features of debate while contributing nothing but slander, smear, falsehoods, and pseudo-reasoning. That said, there is nothing left to do other than pointing out ignorance, or spurious reasoning, as the case may be, so as to have the record corrected.

What's the benefit? Of course, the simplified model (with GHG atmosphere) deviates in many respects from reality, as it captures just one or two basic mechanisms. The difference between "adding more complexity" to save that basic model (along with its flaws) or the ones built on it, and embedding that basic mechanism (back radiation) into a more complex model (closer to reality), should be immediately obvious by now, and the flaws of the simplistic model are not to be found in the more complex ones. That's what I thought was worth pointing out, SSDD's crowing notwithstanding.

ahhh isn't that a sweet a post. he asks a question and you go to the mud. hmmmmm. So is the image correct or not. It's a simple question. why are you avoiding an answer? that isn't considered debate at all, and neither is name calling. that merely shows you're weak.

 

[jc456]

I've moved that text of yours over to the appropriate thread, since here's where that "the model is flawed" action originated, hoping you won't mind.

Don't mind. He cross-posted the same thing in 3 different threads.

I've made up my mind about SSDD, and he isn't debating, or rather, he's behaving as a parasite to debate, taking advantage of features of debate while contributing nothing but slander, smear, falsehoods, and pseudo-reasoning. That said, there is nothing left to do other than pointing out ignorance, or spurious reasoning, as the case may be, so as to have the record corrected.

Yes, I think there is no question that SSDD is just a troll. I know that I along with others have been guilty of feeding the troll. The problem is that he along with his admirers, are wallowing in invectives. The huge bulk of their intense rantings on the "stupidity" of those that don't agree with him may give the impression to others, less involved in the climate question, that he knows what he is talking about.

So, I think his intense ranting is not aimed at the more science savvy. His intended audience is his bootlicking minions and newcomers that may be on the fence about the climate issues.


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so you won't comment on the image?

 

[IanC]

the theoretical maximum temperature of any object being warmed by the Sun is the temperature of the Sun.

Seemingly, if I am following your reasoning correctly, it makes no difference if that object is 100 meters, 100 million kilometers, or a billion light years away. If that's the case, and the earth sure receives energy from from a few billion stars every second and from all directions, and is surrounded and perfectly isolated by a vacuum, why aren't we at 5000°C surface temperature?

????

Because we are not in a perfect insulator. Almost the exact opposite for the Earth as a whole, with space as a limitless depository for radiation expelled, never to return. The Earth's surface has some insulation, the atmosphere, which does return part of the radiation, hence a warmer surface temperature. The more insulation, the warmer the surface temperature, but the theoretical maximum is the temperature of the heat source. Which of course could never be attained due to entropy.

 

[Olde Europe]

Because we are not in a perfect insulator. Almost the exact opposite for the Earth as a whole, with space as a limitless depository for radiation expelled, never to return.

Yeah, but ...

The Sun radiates at a known quantity and quality, but the intensity varies according to the inverse square law (1/d^2). A perfectly insulated object sharing a line of sight with the Sun would warm up to the temperature of the Sun at which point the radiation out would match the radiation in.

... you spoke of a "perfectly insulated object" that radiates out as much as it takes in.

You also said, the theoretical limit would be the temperature of the sun because otherwise that object would warm the sun, again, hinting there's outgoing radiation.

So, again, Ian, how does any of that make sense?

 

[IanC]

Because we are not in a perfect insulator. Almost the exact opposite for the Earth as a whole, with space as a limitless depository for radiation expelled, never to return.

Yeah, but ...

The Sun radiates at a known quantity and quality, but the intensity varies according to the inverse square law (1/d^2). A perfectly insulated object sharing a line of sight with the Sun would warm up to the temperature of the Sun at which point the radiation out would match the radiation in.

... you spoke of a "perfectly insulated object" that radiates out as much as it takes in.

You also said, the theoretical limit would be the temperature of the sun because otherwise that object would warm the sun, again, hinting there's outgoing radiation.

So, again, Ian, how does any of that make sense?

Now you're just talking like SSDD. If you can't separate out one separate mechanism from the background and follow it to a logical conclusion then how are you going to have any understanding of a complex system? Newton's laws are at best incomplete, with no physical examples to prove them. Does that make them less useful? Can you jump from understanding nothing to understanding all without intermediary steps?

 

[IanC]

So, Same Shit, are you saying there is no greenhouse effect?

You ignore and talk past SSDD. Is it any wonder that he does the same to you?

He looks at the problem from a different angle than you. He sees CO2 as a radiator at the top of the atmosphere, you see it as an absorber at the bottom. You both refuse to consider the other's point of view.

He sees the mass of the atmosphere as the main determinant of temperature at the surface, you dismiss because you say it does no work.

I try to integrate all of those factors and more. Which is why I think both of you are fools. Hahahaha

Personally I appreciate SSDD more because he thinks for himself and you just repeat other's thoughts with no understanding.

 

[Olde Europe]

If you can't separate out one separate mechanism from the background and follow it to a logical conclusion then how are you going to have any understanding of a complex system?

I am just trying to understand where you are heading with your argument. You claimed that the sun can heat an object (at whatever distance) to the surface temperature of the sun, at which point radiative equilibrium would be achieved, while that object's radiation is also prevented from getting out of that object's system. That's not a "complex system", that is an obvious self-contradiction, for you can either theoretically create a system that doesn't allow radiation to escape, or one that heads for a radiative equilibrium, meaning radiation escapes, but not both at the same time. Now I am just waiting for you to see it, and either amend your initial wording, which would be interesting, or to leave it there, and move on.

 

[IanC]

If you can't separate out one separate mechanism from the background and follow it to a logical conclusion then how are you going to have any understanding of a complex system?

I am just trying to understand where you are heading with your argument. You claimed that the sun can heat an object (at whatever distance) to the surface temperature of the sun, at which point radiative equilibrium would be achieved, while that object's radiation is also prevented from getting out of that object's system. That's not a "complex system", that is an obvious self-contradiction, for you can either theoretically create a system that doesn't allow radiation to escape, or one that heads for a radiative equilibrium, meaning radiation escapes, but not both at the same time. Now I am just waiting for you to see it, and either amend your initial wording, which would be interesting, or to leave it there, and move on.

Have you studied how Blackbody Radiation was first examined? A container was heated to various temperatures, a small port was opened and the radiation was measured.

My thought experiment runs in the other direction. A perfectly insulated object collects sunlight along a single vector and warms until the source and the object come to equilibrium. There is no loss via 1/d^2, only the characteristics of the radiation from the source.

I am stripping the example down to one process. It is unrealistic, no perfect insulator is possible, no perfect emissivity is possible. So what?

 

[Olde Europe]

My thought experiment runs in the other direction. A perfectly insulated object collects sunlight along a single vector and warms until the source and the object come to equilibrium. There is no loss via 1/d^2, only the characteristics of the radiation from the source.

Now I sense we're getting somewhere, and maybe we all learn something about radiation.

So, we have an object that is so perfectly insulated that neither by way of convection nor radiation any energy can escape, receiving the full impact of the sun's undiluted surface radiation - not subject to the 1/d² law - meaning it is in close proximity to the sun. The insulation lets all radiation in, but none out.

I agree, that object would at one point reach the temperature of the sun.

What happens next? After all no radiation escapes nor any energy otherwise, but the sun still radiates into that object, meaning that the energy content of that object still rises. Shouldn't that object's temperature rise even above the sun's surface temperature?

 

[IanC]

I sense we are getting nowhere if you still think the object can get hotter. Temperature of a blackbody is derived by the quality of its radiation, not its intensity.

 

[Wuwei]

I'm not sure what kind of object you are talking about. If it's totally insulating, then its emissivity is zero. That means it can't absorb nor radiate anything. It reflects all EM.

If it has a little spot or hole (if it's hollow), then radiation can get in and warm it until the temperature of that spot/hole reaches the temperature of the source. Then it will radiate as much as it absorbs.

 

[Olde Europe]

I sense we are getting nowhere if you still think the object can get hotter. Temperature of a blackbody is derived by the quality of its radiation, not its intensity.

I'm not sure what kind of object you are talking about. If it's totally insulating, then its emissivity is zero. That means it can't absorb nor radiate anything. It reflects all EM.

If it has a little spot or hole (if it's hollow), then radiation can get in and warm it until the temperature of that spot/hole reaches the temperature of the source. Then it will radiate as much as it absorbs.

In a way we're talking an extreme version of the Greenhouse Effect. Radiation can get in, but GH gasses are so thick, nothing can get out. This means, as I am trying to argue, that the receiving object can be warmer than the incoming radiation would suggest. Ian does no longer seem to follow the argument at all (see above), and rather repeat what he's been saying, falsely, I am convinced. [Of course, I know the analogy is deeply flawed, since an object approaching the temperature of the sun would radiate at the shortwave spectrum, and thus radiation would get through the GH gasses. But heck, we're merely talking through a thought experiment Ian brought up.] Oh, and BTW, the setup is his idea, the sun's radiation can get in, but no radiation can get out (perfectly insulated), even if that's physically impossible.

Tell me you understand the argument better than he does, please.

 

[IanC]

Some people think you can raise the temperature of a small object to hotter than the Sun by concentrating sunlight via some mixture of mirrors or magnifying glasses. This is wrong. Right next to the Sun's surface is the strongest intensity possible, therefore the hottest temperature. The Sun's radiation at its surface is also diffuse, therefore no magnification is possible. Mirrors go in both directions therefore as the smaller object approaches the Sun's temperature it is radiating almost as much as it is receiving.

Hopefully that clears that topic out.

Point taken.

What do you make of this?

The Sun radiates at a known quantity and quality, but the intensity varies according to the inverse square law (1/d^2). A perfectly insulated object sharing a line of sight with the Sun would warm up to the temperature of the Sun at which point the radiation out would match the radiation in.

Are you questioning the perfect insulation, or the line of sight?

It is an obviously nonrealistic scenario with two objects tethered with a single vector. Radiation can only be passed back and forth along that vector, hence it will come to equilibrium at the same temperature.

Bump for OE

 

[Olde Europe]

the earth sure receives energy from from a few billion stars every second and from all directions, and is surrounded and perfectly isolated by a vacuum, why aren't we at 5000°C surface temperature?

Because we are not in a perfect insulator. Almost the exact opposite for the Earth as a whole, with space as a limitless depository for radiation expelled, never to return.

Bump for Ian.

 

[Wuwei]

In a way we're talking an extreme version of the Greenhouse Effect. Radiation can get in, but GH gasses are so thick, nothing can get out. This means, as I am trying to argue, that the receiving object can be warmer than the incoming radiation would suggest. Ian does no longer seem to follow the argument at all (see above), and rather repeat what he's been saying, falsely, I am convinced. [Of course, I know the analogy is deeply flawed, since an object approaching the temperature of the sun would radiate at the shortwave spectrum, and thus radiation would get through the GH gasses. But heck, we're merely talking through a thought experiment Ian brought up.] Oh, and BTW, the setup is his idea, the sun's radiation can get in, but no radiation can get out (perfectly insulated), even if that's physically impossible.

Tell me you understand the argument better than he does, please.

I think this is a conundrum where the rules have to be refined as you go along. How much is real physics and how much is what-if physics. It's more complex than the well-known, unstoppable object hitting an immovable object.

There are lots of spoilers, like enough heat will blow away the CO2, or as you say, the short-wave radiation leakage. The dense GHG is kind of hard to deal with because it is a scattering medium and will always have some leakage at the top.

However, in the spirit of things it might be simpler to think about an actual greenhouse, where the glass is a perfect highpass optical filter that traps low temperature radiation emission.

I think you actually hit on the actual spoiler. This is my wordier version of your idea. We can even choose a fantasy BB radiation function. As the temperature inside the greenhouse reaches the temperature of the sun, the short-wave portal will be equally efficient at letting out the the same amount in the same band of radiation as the sun is poring in.The long wave aspect of the filter will be unimportant. This is independent of the BB fantasy curve we choose. Equilibrium will be reached when both temperatures are the same.

I have to agree with IanC on this.

As far as a focusing lens, there are limitations with the f-number that will not allow focus of an image beyond the power density of the sun, but I won't go into that here.

 

[Olde Europe]

Equilibrium will be reached when both temperatures are the same.

I have to agree with IanC on this.

In Ian's "what-if physics" (I'm going to steal that) example (all radiation in, none out, as he maintains part time) I see an otherwise closed system into which you continuously pump energy, and that should heat up beyond all limits. At least, common sense would dictate that. In that scenario, the term "equilibrium" makes no sense. And no, in a "real physics" situation, equilibrium is reached when the emission from the object equals the absorbed radiative flux (subject to the inverse square law), and thus the object's equilibrium temperature is way below the sun's, practically and also theoretically. Thank physics for that, for otherwise we'd all be cooked.

Otherwise, I've by now reached the conclusion that Ian's example isn't as enlightening as it seemed initially (even if we could work out the contradictions), as it (as I think you suggested) doesn't really shed a light on the Greenhouse Effect.

I am happy to realize that on the "real" physics side Ian, you and I agree that back radiation is huge, even exceeds the sun's flux absorbed by the earth: 340.3 vs 240,3 W/m². That is the main reason why the earth is at an average temperature far higher than the -18°C it would reach without the GHE. Let the denialings gnaw on that.