måndag 24 oktober 2011

Radiation Double-Speak

In politics it is necessary to use words with multiple meaning to allow different people to make different interpretations of words like "equality", "liberty" and "justice". The society of Orwell's 1984 can only exist with doublespeak.

Doublespeak is also used in science, although in principle scientific terms are supposed to be well defined. An example of a term with double meaning is "radiation" which is used in two different ways:
  1. as immaterial electromagnetic wave
  2. as transfer of heat energy between material bodies.
In a wave model it is possible to make a distinction between 1. an electromagnetic wave as an immaterial carrier or medium for the 2. transfer of heat energy between material bodies. An essential scientific question the concerns the interaction of emission and absorption between the immaterial wave and the material body as the heat energy is transferred.

It is possible to allow the waves to be two-way, while the transfer of heat energy is one-way from warm to cold, as shown in Computational Blackbody Radiation and Mathematical Physics of Blackbody Radiation.

This distinction is however not possible if a particle model is used, if radiation is viewed as a stream of "energy quanta" or photon particles, since then the carrier is the same as the carried energy (in analogy with Marshall Macluhans "the medium is the message").

In a particle model the processes of emission and absorption are viewed as as a "spitting out" and "swallowing" of photons or "packets of heat energy" or "quanta", in a primitive line of thought. The transfer of heat energy like particle motion becomes two-way, with the body spitting the most winning a game of heat transfer.

The confusion in the debate on DLR/backradiation as the basis of the greenhouse effect of CO2 alarmism, comes from the doublespeak of radiation as both 1. and 2. This makes it possible to speak about "radiation from the colder atmosphere to the warmer Earth surface" as "Downwelling Longwave Radiation" even if such a transfer would violate the 2nd law.

The particle model of light introduced by Newton was replaced by Maxwell's wave model in the late 19th century, but was then surprisingly reintroduced by the early Einstein and Planck while the late Einstein did not accept that idea of light as a stream of particle quanta.

A particle model of light is indeed very primitive and lacks in particular for IR or microwaves, all rationale because the wave length is millions of times larger than the atomic dimensions.

A primitive particle model allows doublespeak flipping back and forth between 1. and 2.
and this is cleverly used by CO2 alarmists to meet critique that DLR/backradiation
violates the 2nd law. But this is primitive and is no longer possible if a less primitive wave model is used.

Note that Planck in the Faustian deal of previous post made in the preface to his Theory of Heat Radiation, struggles to explain why he has given up a wave model of radiation, in order to give the impression that he is not using doublespeak of both particle and wave.

But Planck did not save modern physics from doublespeak, with the wave-particle duality as
the ultimate expression of doublespeak, elevated to virtue in modern physics.

Notice that an electromagnetic wave cannot store energy, while a material body can store energy as heat: As soon as the light emission form a material body is turned off, the light goes off, and there is no light to be absorbed. This shows that the electromagnetic wave is a carrier of energy without capacity to store energy itself. An electrical circuit with capacitor and inductor can store energy, but not a light wave.

In a particle model the stream of particles as energy quanta represent stored energy, and again the distinction between the immaterial transmitter of energy and and material energy becomes muddled.

12 kommentarer:

  1. "In a wave model it is possible to make a distinction between 1. an electromagnetic wave as an immaterial carrier or medium for the 2. transfer of heat energy between material bodies"

    No it isn't. Waves carry energy.

  2. I have updated to emphasize that waves can propagate two-way while heat energy only one-way. Therefore it is not enough to say that waves carry energy to make the wave the same as the energy transfer, that is to make 1 and 2 the same. 1 and 2 are not the same and if this distinction is not made, confusion results. It appears that some commentators seek confusion rather than clarity.

    To Dol: It is up to you to find something useful in what I am saying. You don't have to and I am not insisting that you should.

  3. "It is possible to allow the waves to be two-way, while the transfer of heat energy is one-way from warm to cold."

    And the same is true if you prefer to think about quanta. Your thinking is too primitive to grasp quantum physics, it seems. Your views on light and radiation are literally centuries out of date.

  4. Exactly, I want to revive rational thinking as deterministic continuum mechanics, which has been replaced by irrational particle statistics, with the latter representing primitivism. Lots of people seem to prefer primitive science, but that does not make it more admirable.

  5. Are you asserting that no energy is associated with the vibrations of electric and magnetic fields of a radiating electromagnetic wave?

    But then how exactly is energy transported "as a transfer of heat energy between material bodies" in your understanding?

  6. Yes, electromagnetic waves have energy, but has to be sustained by emission from a material body (or by inductor/capacitor).

  7. So, whether it's a wave or a particle, you agree that it is carrying energy, correct?

    Now a wave can be shaped - AM radio works this way, so that sound is imprinted on the amplitude of oscillation of the radio waves. In your view, what is the magnitude of the energy of the radio wave at my car, relative to the magnitude at the broadcasting station. It is always identical at a given point in time (aside from the inverse square law decay)? How does the finite speed of light factor in?

  8. Arthur, look at this an maybe you will learn something http://www.worldsci.org/pdf/abstracts/abstracts_5711.pdf

  9. You must be one of the first persons who call Quantum Electro Dynamics primitive ;-)

  10. Beware of mistaking the wave equation. The general solution of the differential equation gives us all the possible wave traveling way.
    But the general solution is a physical nonsense. What really occurs is determined by the boundary conditions which cause only one real effect that can be whether a one way traveling wave or a standing wave.

  11. Claes,

    what is your stance concerning QED?

    One can argue that QED is much more descriptive when dealing with fundamental interactions (which must be seen as the basis for the problems discussed here).

    You are asking really fundamental questions about light-matter interactions here.

    One can further argue that QED is a much larger theory than Maxwell's since it,

    1) Explains many more phenomena then Maxwell's equation, including all phenomena in Maxwell's theory since,

    2) As you probably are familiar of there is no problem at all to derive Maxwell's equations from the QED Lagrangian (I did this myself a while ago) so Maxwell's theory is contained in QED.


  12. If QED can be used to say something intelligent about blackbody radiation,
    I would be interested in seeing that.