tisdag 25 oktober 2011

Radiative Heat Transfer: Phlogistons and Photons


I will now argue that phlogiston theory has similarities with photon theory of light in the case of infrared radiation of global climate.

Phlogiston theory says that all combustible resources contain particles named phlogistons without colour, odor, taste or mass, which are liberated in burning.

Photon theory says that light consists of particles named photons without mass and charge carrying energy along straight lines at a constant speed of light. Photons have different frequencies and and energy proportional to frequency.

Photon theory describes radiative heat transfer between two bodies as a two-way stream of photons emitted/absorbed by the bodies, with the hotter body emitting photons of higher frequency and in higher numbers as compared to the colder body, which results in a net transfer of heat energy from hot to cold.

Photon theory is a particle theory of light going back to Newton's corpuscular theory of light,
and is to be compared with the wave theory of light as electromagnetic waves described by Maxwell's equations. The wave theory of light describes almost all observed phenomena of light.

The wave theory of light replaced the particle theory in the late 19th century, but was revived in the early 20th century by Planck to describe blackbody radiation and by Einstein to describe the photoelectric effect.

Phlogiston theory is no longer taught, but the photon theory of light is still used to explain certain phenomena believed to be difficult to explain by a wave model, typically related to the
phenomena of emission and absorption involving interaction between matter and electromagnetic waves. In photon theory emission is seen as ejection of photon particles and
absorption as the opposite.

For visible light, emission of photons as finite quanta of energy can be associated with discrete changes of atomic electronic structure. For infrared radiation with much larger wave lengths than atomic dimensions, the interaction between matter and waves must involve collective motion of many atoms and the photon theory does not seem to be applicable.

This mean that photon theory cannot be used to describe blackbody radiation at the modest temperatures of global climate. In this case the photon theory is similar to the phlogiston theory as a very simplistic theory with little predictive capability, and a wave theory based on Maxwell's equations can be preferable, as shown in Mathematical Physics of Blackbody Radiation.

The fact that photon theory can be useful for certain applications at high-energy short wave-lenghts, does not mean that it is also uselful for completely different applications at low-energy long wave-lengths.

Nevertheless, the photon theory serves as support of the propaganda of CO2 alarm based on
the idea that streams of photons from the atmosphere contribute to global warming as DLR/backradiation, which rather represents phlogiston theory than real physics.


30 kommentarer:

  1. When you say that there must be collective motion of many atoms does this include spectral lines from hydrogen spectroscopy?

    Sincerely,
    Dol

    SvaraRadera
  2. Not necessarily, that is short wave-length.

    SvaraRadera
  3. Same question but for carbon dioxide then... ;-)

    Or some di-atomic molecule...

    Sincerely,
    Dol

    SvaraRadera
  4. Coordinated collective motion is required because of the long wave-length.
    But even for short wave-length is coordination required.

    SvaraRadera
  5. Claes wrote:
    Coordinated collective motion is required because of the long wave-length. But even for short wave-length is coordination required.

    Is this something that is supported by experiments?

    SvaraRadera
  6. When a proton and an electron change from parallel to antiparallel spins, a microwave photon with wavelength 21cm is emitted. Regardless of wavelength, there is no problem with the concept of photons. Your physics is a century out of date and this is probably why you're coming to such desperately wrong conclusions.

    SvaraRadera
  7. Claes, you should take a look at the following article.

    http://people.whitman.edu/~beckmk/QM/grangier/Thorn_ajp.pdf

    And if that is not enough for you regarding the photon nature of light I will have further suggestions for you.

    Sincerely,
    Dol

    SvaraRadera
  8. A proton and an electron generating a photon particle with wave length 21 cm seems strange to me. I am not the only one viewing IR-photons with suspicion. Einsteoin for one was skeptical.

    The process of emission of IR does not seem to be well described in the literature. But nobody has seen an IR-photon so they do not seem have experimental support.

    SvaraRadera
  9. To Dol: The experiment uses UV-light and not IR. What is your experiment showing that IR-photons exist?

    SvaraRadera
  10. "But nobody has seen an IR-photon so they do not seem have experimental support"

    Ha ha, very good. Try googling "infrared astronomy" and you might learn something that will astonish you.

    SvaraRadera
  11. Single photon detectors exist and they work for IR frequencies as well, as described in this paper in Nature

    http://www.nature.com/nature/journal/v403/n6768/abs/403405a0.html

    SvaraRadera
  12. It showes that photons exists.

    Are you still incisting that photons doesn't exist?

    My recomemndation is that you contact someone that works in the field of quantum optics and see if they can help you to get ahead with the current situation regarding experiments.

    Sincerley,
    Dol

    SvaraRadera
  13. It is stated "We detect, with a time resolution of a millisecond, an incident ̄ux of 0.1 photons per second on an effective detector area of 0.1mm2Ða sensitivity that exceeds previously reported values by a factor of more than 10^4".

    To detect 0.1 photons per second does not seem to be a lot. Does this explain global warming by DLR?

    SvaraRadera
  14. Concerning non-existence of photons see e.g.
    http://aporia.byu.edu/pdfs/manchak-arguments_concerning_photon_concepts.pdf

    SvaraRadera
  15. Claes, you know full well that when individual events are counted over a length of time the average number of event per unit time can be less than 1.

    The average number of goals per minute in a football game is less than 1 in a good game, and that does not prove that there are no goals made.

    SvaraRadera
  16. If it takes 10 seconds to record 1 photon, and a photon travels at the speed of light, how long is then a photon? 0 or 3.000.000.000 m?

    SvaraRadera
  17. Claes, why in heaves do you think that it takes 10 seconds to detect a photon?

    Did you try to read and understand the paper or did just look at the abstract and start making jokes?

    SvaraRadera
  18. Claes wrote:
    Concerning non-existence of photons see e.g.
    http://aporia.byu.edu/pdfs/manchak-arguments_concerning_photon_concepts.pdfz


    Yes, and if you read it you see that it is argued for a photon model that isn't classical but quantum electrodynamical...

    And it further strengthens my proposition that you should contact someone that is well aquinted wid QED.

    Sincerely,
    Dol

    SvaraRadera
  19. Claes wrote:
    If it takes 10 seconds to record 1 photon, and a photon travels at the speed of light, how long is then a photon? 0 or 3.000.000.000 m?

    No offens, but are you drunk?

    Sincerely,
    Dol

    SvaraRadera
  20. Yes I am joking about photons. And about wave-particle duality. And DLR...

    SvaraRadera
  21. Claes wrote:
    Yes I am joking about photons. And about wave-particle duality. And DLR...
    So you finally admit that you got it all wrong? ;-)

    Sincerely,
    Dol

    SvaraRadera
  22. Whether you prefer to believe in a 200 year old picture of what electromagnetic radiation is, or a contemporary one, you still have to come to terms with the fact that electromagnetic radiation from the atmosphere is directly detected. But I don't think you can come to terms with simple observations, can you?

    SvaraRadera
  23. Further, it isn't shown yet that a classicle picture isn't consistent with a two-way transfer with net from warm to cold.

    Claes, you should show, with equations, why you consider a two way transfer is violating the second law.

    Sincerely,
    Dol

    SvaraRadera
  24. Dol & others who seem to lack understanding of technology look at this by a physicist http://arxiv.org/abs/1009.5119 who extends the thoughts of nobel prize winning physicist WE Lamb Jr. Also look at this by an engineer who has prctical experience and test data about radio waves and light amplification http://www.worldsci.org/pdf/abstracts/abstracts_5711.pdf.
    The electromagnetic spectrum is a continium covering a large range of frequency of waves from gamma & X-rays, through infra-red & mircowaves to radio waves. Has anyone ever proposed that mircowaves or radio waves were photons? Note the terms VHF (very high frequency), AM (amplitude modulated) FM (frequency modulated)etc.
    When science professors at university do not understand basic theory and ignore experimental and design work by engineers what hope is there for undergraduates.
    cementafriend

    SvaraRadera
  25. There is no classical mathematical model (equations) describing two-way transfer of heat energy, only an ad hoc primitive corpuscular model with trivial
    equation for a straight line.

    SvaraRadera
  26. No mathematical model? That's a very bone-headed claim.

    Imagine a body with a mass of 1kg, a density of 1kg/m$^3$ and a radius of 1m at a temperature of 100K. It will radiate energy at a rate of

    E$_1$=4$\pi 1^2\sigma(100)^4$

    Now, let's imagine another body. It can be the same size and mass. This second body has a temperature of 80K. It radiates at

    E$_2$=4$\pi 1^2\sigma(80)^4$

    Let's assume both bodies contain a source of energy equal to these numbers so that their temperature is constant.

    Now let's put them near each other, a distance of 2m apart. Let us make a very crude approximation and consider each body separately for a moment. The cooler body now contains its heat source with power E$_2$, and it also absorbs energy from the hotter body. So its temperature goes up.

    $4\pi R^2\sigma T_new^4$ = $E_1 + E_2 \times \frac{\pi R^2}{4\pi 2^2}$

    Work it out, you get a new temperature of 82.89K for the smaller body. Now consider the hotter body.

    $4\pi R^2\sigma T_new^4$ = $E_2 + E_1 \times \frac{\pi R^2}{4\pi 2^2}$

    Work it out, you get a new temperature of 100.63K for the hotter body.

    Clearly this is not an equilibrium calculation and the actual temperatures will be higher. Nonetheless, it is enough to show that the cooler body gets hotter, and so does the hotter body.

    SvaraRadera
  27. Of course a body heated from inside will reach a higher temp if the background has a higher temp.

    SvaraRadera
  28. A typical CJ answer: put the focus on something else...

    But the question was the existence of a mathematical model.

    SvaraRadera
  29. Anonym wrote: ”Nonetheless, it is enough to show that the cooler body gets hotter, and so does the hotter body.”
    This is not at all a proof of the two way transfer of the heat energy between the two bodies. Indeed, if you protect the body 1 or 2 with a shield wholly blocking any entering/exiting radiation, its temp will rise until the infinity and that simply because it isn’t able to emit.
    In your example the two bodies partially shield themselves each other. That reduces the effectiveness of their one way radiating and so both increase the equilibrium temp because their emitting power must remain constant.
    Michele

    SvaraRadera