Energy conservation thought experiment

My mistake we are talking about GAMMA radiation. It would stretch things to assert that the actual gamma entering were the same object exiting the target crystal. With a Q of 10^10 a fractional mm/sec relative motion would have to be explained by resulting target recoil where zero relative motion results in a recoiless emission of a gamma (.129Mev). Even at low temperatures the crystal lattice has vibrational motion so the actual target molecule is not rigidly bound to the lattice.

The reaction is a nuclear reaction and the gamma, a electromagnetic entity cannot have its energy altered by motion of the source (DeSitter). The change in wavelength, if any, due to the source motion cannot be ascribed as a change in energy to the extent that a nuclear absorption and reradiation is the result of such an energy difference. There is something going on other than nuclear resonance spectroscopy here.

I don't understand what you mean that "zero energy can be passed through the lattice". If anything is passed it must have a nonzero energy, correct? Moving to or away from the target results in a measured recoil even if the relative speed is fractional mm/sec. As I understand the literature the nuclear absorption and reemission is what is occuring, with the source and target being crystal lattices. I am not denying all the experimental results and I have personally observed the Mossbauer effect. As you said the gamma hits the component and is then reemitted, or better a gamma is reemitted, from the component. But the recoil energy cannot be ascribed as measured by the velocity difference of source and target - if the relastive velocity of source and target is zero what is emitted from the target is a gamma emitted from the target as if one has simply placed an object into a container that was already full - this is analogous to a gamma appearing in the component that must emit a gamma in order to maintain conservation of energy within the component and the entering gamma is identical to the host gammas in the component (assuming for the sake of argument that the component has a 'gamma' compartment, or some mechanism similar to a gamma compartment.) If the incoming gamma is not of the same structure as the host target 'gamma compartment' then entry is forced, as if the incoming gamma were too large, hence forces maintaining equilibrium result in recoil. If the incoming gamma is too small, the component gamma compartment is still in a state of disequilibrium such that maintaining equilibrium requires a borrowing of gamma characteristics necessitating a recoil.

I recognize the proplem in using terms such as gamma compartment etc but the standard explanation using the lattice with the observed sensitivity, even at low temperatiures doesn't ring my bell of understanding. ,

 

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AN;
See room temperature Mossbauer which I show here as opposing the lattice absorption mechanism - we may be a tad far afield from QQ's thread.
http://www.springerlink.com/content/18x3h412g64v23p3/

 

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Well, you would have to provide a reference frame. Otherwise you couldn't define a location and velocity of the mass in the first place. And if your reference frame is such that the mass is initially resting at the origin, then you will find afterwards that the overall center of mass is still resting at the origin. It is just that the remnants of the mass are distributed over some range and moving in opposite directions.

Thomas

 

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