fredag 23 juli 2010

Cutoff of Backradiation by Ockham's Razor

The discussion in previous posts on the non-physical nature of backradiation directly connects to the physics of blackbody radiation studied in Computational Blackbody Radiation in a mathematical model of the principal form (in stationary state)
  • R = LR + HR 
where R is incoming absorbed radiation by a blackbody B at temperature TB, where the radiation originates from a body A at temperature TA bigger than TB and thus contains  both low and high frequencies, LR is the low-frequency infrared part of R after cut-off of the high-frequency part HR with the level of cut-off defined by TB.

We thus assume that the blackbody B is heated by A, because cut-off requires something substantial to be cut-off.  A thief seeks a richer to rob, not a poorer.

We know that the spectrum of R carries its emission temperature, assuming it follows Planck's Law, and thus B at absorption can check if there is some radiation to absorb and process (without having access to the temperature of A, only to the radiation from A about to be absorbed).

We thus consider a body B which is absorbing radiation R of a temperature bigger than its own.
The model describes how the body B handles this situation by cutting off the high frequency part HR (grinding it into low frequency heat) and ends up with a low frequency part LR which is prepared for emission. 

We thus focus on the absorption process with the cut-off and we can leave the emission process out of the discussion. The advantage is that that we do not have to deal with a two-way communication between A and B,  with a hypothetical backradiation from B at low temperature to A at high temperature.

By focussing on incoming instead of outgoing radiation, we focus on what is essential, and leave out what is inessential. We thus make use of Ockham's razor as the basic principle of science.  

To sum up: 
  • It is interesting to study the absorption by the Earth of radiation from the Sun, but not interesting to study the absorption by the Sun of radiation from the Earth. 
  • It is interesting to study the absorption by the atmosphere of radiation from the Earth, but not interesting to study fictional backradiation from the atmosphere to the Earth.
Note that Ben Herman and Roger Pielke in the post The Greenhouse Effect of today, start off:
  • During the past several months there have been various, unpublished studies circulating around the blogosphere and elsewhere claiming that the “greenhouse effect” cannot warm the Earth’s atmosphere. 
It is possible that my blog is involved. Herman and Pielke now seek to correct what is circulating by explaining the arguments that have been put forth and why they are incorrect: 
  • When absorbing gases are added to the atmosphere, more of emitted radiation from the ground is absorbed by the atmosphere. This results in increased downward radiation toward the surface, so that the rate of escape of IR radiation to space is decreased, i.e., the rate of infrared cooling is decreased. This results in warming of the lower atmosphere and thus the second law is not violated. Thus, the warming is a result of decreased cooling rates. 
We here meet exactly what Ockham's razor cut off, namely "downward radiation". What is the truth? Fiction or non-fiction? Is my argument incorrect?

Note that Herman and Pielke use quotation marks around the greenhouse effect and also speak about the 
  • so-called "greenhouse theory"
with their own quotation marks. But if you put quotation marks around theory, doesn't that indicate that it is not a theory, but only a "theory". What is then the  status of "theory" in science? Is it a "theory" because it is only folklore and not described in physics literature?

Of course the presence of an atmosphere can affect the temperature on Earth, in many ways: Is this the meaning of the "greenhouse theory" and "greenhouse effect"? Maybe it would then be better to call it "atmosphere effect", but it remains to tell what this effect is.

3 kommentarer:

  1. Your arguments and analogies are frankly ridiculous. I showed you a paper some time ago which described measurements of infrared radiation from the atmosphere, and yet you still claim that this radiation does not exist.

  2. Roger, I've concluded that Claes is only interested in a monologue, he has outgrown the need to listen to others being convinced that he knows everything and that the more people object the more right he is. It happens to some scientists when they grow old.

  3. Yes, it certainly looks that way. Well, if he doesn't like people disagreeing with his foolish views, then he should not be running a blog.