All Scientists are Sceptics ~Professor Bob Carter

Whenever someone asserts that a scientific question is “settled,” they tell me immediately that they don’t understand the first thing about science. Science is never settled. Dr David Deming

Perhaps the most frustrating aspect of the science of climate change is the lack of any real substance in attempts to justify the hypothesis ~Professor Stewart Franks

A lie told often enough becomes the truth.
-- Vladimir Ilyich Lenin - See more at: http://thepeoplescube.com/lenin/lenin-s-own-20-monster-quotes-t185.html#sthash.aTrSI3tG.dpuf
A lie told often enough becomes the truth.
-- Vladimir Ilyich Lenin - See more at: http://thepeoplescube.com/lenin/lenin-s-own-20-monster-quotes-t185.html#sthash.aTrSI3tG.dpuf
A lie told often enough becomes the truth.
-- Vladimir Ilyich Lenin - See more at: http://thepeoplescube.com/lenin/lenin-s-own-20-monster-quotes-t185.html#sthash.aTrSI3tG.dpuf

Monday, 25 May 2015

THE GREENHOUSE EFFECT

NZCLIMATE TRUTH NEWSLETTER NO 343

MAY 24th 2015

by IPCC Expert Reviewer Dr Vincent Gray


THE GREENHOUSE EFFECT

The history of the greenhouse effect is given in Chapter 5 of my book at

The term arose when Fourier misinterpreted the heating  in de Saussure's Hot Box (a miniature greenhouse) as caused by reflection of internal infrared rays by the glass top.

He believed that the earth was heated by the ether but not by the sun. He thought all the heat from the sun was immediately lost by infra red.

He needed some extra heat, just for the tropics, and he speculated that water vapour might behave in a similar way to the hotbox glass cover

These views were adopted by Tyndall who measured resistance to passage of infra red radiation through a large number of gases, including carbon dioxide, and found that the absorption was small, but when he tested water vapour the effect was so large that the apparatus could not measure it.

He therefore concluded that Fourier’s idea that water vapour heated  the earth was plausible.

Both of them regarded radiation as a form of Heat which required a medium for its transfer. The ether was needed to permit its passage through space of radiant heat.

It was accepted that heat could only pass from a hot object to a cold object. This principle was the Second Law of Thermodynamics which also applied to complete systems. Its application to heat transfer was eventually explained as a passage of the mechanical energy which exists as random movement of atoms and molecules of all substances. The level of this movement is the temperature of the substance.

It eventually became evident that Heat of radiation is fundamentally different from the heat stored by ordinary objects. Maxwell, in 1873, postulated that all radiation, over a wide spectrum, is a wave motion consisting of alternate oscillating electrical and magnetic fields.

The energy E of radiation is obtained by the Stefan/ Bolzmann equation:-
E = CxT4

C is Stefan’s constant and T is the absolute Temperature (to the fourth degree of the emitting substance.  Notice that it is entirely determined by this temperature of the emitting substance.

The published derivations of the Stefan/Boltzmann law treat the emitting substance as a black body. This  does not imply that the equation appiies only to solids. Liquids and gases also consist of molecules in motion and they a;so emit radiation/ In addition real substances are not ideal black bodies, so the equation needs an additional emissivity factor. Planck derived an equation which provided the spectral distribution, after allowing for the quantum effects.

Radiation energy is converted to heat if it is absorbed by any suitable object. The temperature of that object is quite irrelevant. The speculation by some that radiation cannot be absorbed by an object whose temperature is less than that of the radiant emitter requires the absurd assumption that radiatio, is capable of detecting the temperature of distant objects before deciding whether they are fit to receive absorption. Such an assumption restores the need for a belief in the existence of an ether.

It is unfortunate that several dictionary definitions, physics textbooks and even school and university courses in physics fail to  make the distinction between heat that is transferred by mechanical action and radiant energy which only becomes heat when it is absorbed by a suitable body. This  confusion is mainly due to the time it has taken for the earlier concept of radiation as a form of heat which passess through the ether as a medium, to radiation which does not need a medium and has different properties from ordinary.

The Michelson Morley experiment of 1887 followed by Einstein’s relativity theory showed that the ether did not  exist and was unnecessary for the passage of radiation

Arrhenius, in 1897, no longer  believed in an ether but he foolishly ignored the advice of Fourier and Tyndall by using Langley’s primitive measurements of atmospheric absorption to assume that they related to atmospheric carbon dioxide. He failed to realise that Langley’s figures at that time did not include the main absorption bands of carbon dioxide, so Arrhenius’ calculations were for water vapour.

So the greenhouse effect does exist. 

Greenhouse gases, predominantly water vapour, do absorb infra red radiation from the earth, radiate the additional energy in all directions, including downwards and  so warm the earth. This effect must be very small as it has not been detected, despite the enormous effort that has been applied to try and find it.

  
Cheers 

Vincent Gray
Wellington 
New Zealand


5 comments:

  1. Yes Vincent, an a body is capable of determining the temperature of a distant object because that is encoded in the spectrum of the emitter in the form of Wien's displacement law.

    ReplyDelete
  2. "The speculation by some that radiation cannot be absorbed by an object whose temperature is less than that of the radiant emitter..."

    ---That "less than" must be a mistake, as no one speculates that a cooler object cannot absorb heat from a hotter one. It should read "more than", as in, a hotter object cannot be heated by a cooler one. Dr. Gray (along with the "consensus" alarmists and all the "lukewarmist" believers in the greenhouse effect) is denying even the latter when he states that "backradiation" from CO2 (in the cooler atmosphere) further warms the planetary surface; he is wrong, and merely covering his error by admitting that the warming due to such backradiation "must be very small as it has not been detected, despite the enormous effort that has been applied to try and find it." The definitive evidence against the consensus greenhouse effect is my Venus/Earth temperature-vs-pressure comparison, which simply shows it does not exist, and the CO2 climate sensitivity is (-0.026 +/- 0.12) °C per doubling of CO2--the possible size of the effect is one-fifth of the uncertainty in the calculation and is thus essentially zero. While an individual photon from a cooler object may very rarely be absorbed by a warmer object, that is essentially on the microscopic scale; macroscopically, photons from a cooler object cannot be absorbed by a warmer object. Failing to distinguish between rare events that are possible on the quantum scale, but not in the macroscopic, bulk transfer of heat energy, is the common error of all believers in the greenhouse effect. It really does boil down to the simple proscription against a cooler body further warming a warmer body, as the definitive Venus/Earth evidence (which compares an atmosphere with .04% CO2--Earth--to one with 96.5%--Venus; the difference could hardly be greater, and the result--zero sensitivity to CO2--is definitive) simply demonstrates to anyone with eyes to see (and very few do, as I did that comparison 4 and 1/2 years ago and it is still ignored by both sides). 97% of both sides in the debate are incompetent (and that includes, unfortunately, even Dr. Gray).

    ReplyDelete
  3. We agree Harry on the non-physics of two-way radiative heat transfe including "back radiation" from cold to warm, and so we are at least two who understand that transfer from cold to warm violates the second law. But people like Vincent use to say in defense that in fact the net transfer is from warm to cold, and so the violation of the 2nd law is only appearent. To such people I have posed the question if radiative heat transfer can be mathematically modeled only in terms of net transfer, and some the say that they believe this is possible. Once this has been established it is then an easy job to use Ockham's razor to cut off the "back radiation" two-way gross transfer as something superfluous which can be out into the history cabinet of useless confusing potentially scientifically destructive concepts which has no place in true physics. Right?

    ReplyDelete
    Replies
    1. Dr. Johnson,

      I (Will Janoschka) would like to reply but cannot, as this site refuses to accept my name on WordPress as this site insists on changing that to (Will%20Janoschka). P
      Please help from any! wiljan@pobox. com

      Delete
  4. Vincent: I have posted a comment on my blog including a question to you:
    http://claesjohnson.blogspot.se/2015/05/does-undetectable-greenhouse-effect.html

    I would appreciate an answer, if you happen to read the comments to your post.
    Sincerely, Claes.

    ReplyDelete





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