Radiation energy hypothesis

The basic hypothesis is that in ecosystem A the only original source of energy and matter for all forms of life is solar radiation energy (E). According to numerous theoretical and experimental studies, sunlight penetration into deep layers of the... 

The Big Bang hypothesis requires an instantaneous beginning of our universe at a point to which all energy (in the Planck-Einstein matter-radiation-energy concept Ch. 12) is concentrated. Ordinary nuclear reactions cannot model this beginning and we must turn to particle physics for information (Ch. 10). 

Chemists are aware of many types of reactions which radiate energy-exothermic ones, luminescent ones and physicists are aware of many forms of radiant matter. Protoplasm is not less active than these, not less dynamic than the radioactive elements, potassium, rubidium, and even radium, which it contains. Glasser (27) has conservatively reviewed the hypothesis of Gurwitsch. 

Analysis of the state of theory and experiment concerning IBB radiation and the mathematical description of the phenomenon led Planck to recall Newton s hypothesis that light is a stream of particles (corpuscles) this had been rejected on the basis of successive woiks on interference and diffraction. Planck suggested a revolutionary idea that each particle of radiation is a corpuscle or quantum, i.e., a particle bears a portion of energy hv = hco where /i is a certain constant, and h = hl2n. Then the total radiation energy flux should be expressed by the total number of quanta, hco, i.e., E = where bco is the energy... 

This is known as the Stefan-Boltzmaim law of radiation. If in this calculation of total energy U one uses the classical equipartition result = k T, one encounters the integral f da 03 which is infinite. This divergence, which is the Rayleigh-Jeans result, was one of the historical results which collectively led to the inevitability of a quantum hypothesis. This divergence is also the cause of the infinite emissivity prediction for a black body according to classical mechanics. 

Bohr s hypothesis solved the impossible atom problem. The energy of an electron in orbit was fixed. It could go from one energy level to another, but it could not emit a continuous stream of radiation and spiral into the nucleus. The quantum model forbids that. 

The constant h and the hypothesis that energy is quantized in integral multiples of hv had previously been introduced by M. Planck (1900) in his study of blackbody radiation. In terms of the angular frequency a> deflned in equation (1.2), the energy E of a photon is... 

There are new ideas and experiments on the rTCA cycle. A group from Harvard University studied some reaction steps in the rTCA cycle which were kept going by mineral photochemistry. The authors assumed that solar UV radiation can excite electrons in minerals, and that this energy is sufficient to initiate the corresponding reaction steps. In this photocatalytic process, semiconductor particles were suspended in water in the presence of a zinc sulphide colloid (sphalerite) the experiments were carried out in a 500 mL reaction vessel at 288 K. Irradiation involved a UV immersion lamp (200-410 nm) in the photoreactor. Five reactions out of a total of 11 in the rTCA cycle were chosen to check the hypothesis ... 

First, we want to make a comment about possible local temperature rise due to energy absorption. An early theory of radiation effect s was based on the point-heat hypothesis (Dessauer, 1923). Later analysis showed that the temperature rise would be too feeble and too transient for low-LET radiation to cause any real change (see Mozumder, 1969). There is no experimental evidence for temperature rise for low-LET radiations. The case of high-LET radiations is still open, though. 

Until now, no certain evidence of the existence of GWs has been found. However Hulse and Taylor, studying the PSR 1913+13 binary system of pulsars, found that experimental data were fully coherent with the hypothesis that part of the system energy was lost through gravitational radiation [52-54],... 

Second, the radiation hypothesis, pursued from the early 1900s through the 1920s by physicists and physical chemists, proposed a radiation- and energy-based mechanism for activation of intermediate steps in the chemical reaction mechanism, molecule by molecule. But, in the short run, this theory proved wrong. Nonetheless, the radiation hypothesis is interesting for our study because it demonstrates the development of an abstract mathematical and phys-... 

Perhaps Perrin s continuing commitment is explained by the fact that his radiation hypothesis was an update of Marie and Pierre Curie s original explanation of radioactivity, that the apparently spontaneous emission of radiations and charged particles from molecules is activated by immanent radiations. The Curies supposed that radiations in the atmosphere or in the ether disturb the stability of the naturally radioactive elements. This hypothesis, like the radiation hypothesis of chemical activation, eventually succumbed to an explanation using electron configurations, adumbrated by the new quantum interpretation of matter and energy. 

The only apparently viable alternative mechanism to explain the observed unimolecular behavior is one that was originally proposed in 1919 by Perrin and became known as the radiation hypothesis. In the absence of any significant body of kinetic data, Perrin proposed that reactant molecules obtain the energy required... 

Studies at Lawrence Radiation Laboratory (LRL) (Kury et al (Ref 7) quoting Wilkins) indicate that in 1-D systems a twofold volume expansion of the detonation products is sufficient to transfer the maximum amount of energy to a metal in contact with these detonation products, but for tangential incidence (2-D systems) a sevenfold volume expansion is required. They state that for explosively driven cylinders observations of the early stages of expansion are expected to provide information on 1-D systems, and measurements of the later stages of expansion are expected to characterize 2-D systems. We will consider their hypothesis in Section IV... 

There are several reasons for starting this account with a discussion of electromagnetic radiation. Historically, it was in this area that the quantum theory first developed. It is easier here to understand the evidence for the theory, and to appreciate some of its paradoxical consequences, than it is in the quantum theory of matter. The applications of the light-quantum hypothesis, as it was first called, also provide key pieces of evidence for the quantization of energy in atoms and molecules. Studies of the absorption and emission of radiation—the field of spectroscopy—and of the effect of light on chemical reactions—photochemistry—are very important areas of modem chemistry, in which the quantum nature of radiation is crucial. 

The most natural source of energy for the activation of molecules is molecular collision, but since the rate is independent of the number of collisions it would appear at first sight that the simple collision mechanism can not be responsible for the activation. Three hypotheses have been proposed to account for the activation process the radiation hypothesis, the elaborated collision hypothesis, and the hypothesis of chain reactions. 

According to the third postulate the energy of activation may be set equal to hv (Planck s constant X frequency of light absorbed) in agreement with the quantum theory which has been so successful in many different fields. There is no support for this hypothesis, except the general success of the quantum theory (whenever applied to radiation phenomena, and chemical activation was assumed to be a radiation phenomenon. 

We have seen that neither the requirements for activation energy nor the fact that the rates of unimolecular reactions are independent of collision frequency can be explained on the basis of the simple collision hypothesis or the radiation hypothesis. The elaborated collision hypothesis is able to explain them on the assumption of a time-lag in complex molecules between activation and decomposition. In this way a single molecule can collect energy from many successive collisions and store up a sufficient amount for activation. Just because a given hypothesis accounts for the facts, is no reason to consider that the hypothesis has been proved. There may be other hypotheses which will account equally well for the facts. The hypothesis of chain reaction offers a competing hypothesis which up to the present time has been increasing in favor. 

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