Eventually the energy would become heat which I assume appears like incoherent phonons, but initially it would be generated as waves propagating outwards from the point at which it is thermalized. Here outwards should be interpreted as more like a circular wave front emitted from that point in space due to the conservation of momentum. Any motion of atoms as a whole in one direction must have a balancing set traveling at 180 degrees. The low momentum of the emitted IR can not result in any increase to the net momentum of the system. The reaction to the IR emission would result in the recoil of the atom that does the emission to balance the initial impulse.
I think of this situation as similar to what is seen when a very high velocity bullet impacts a drum full of water. The net behavior appears more like an explosion occurring within the drum with water exiting in all directions. In that case the conservation of momentum ensures that a calibrated extra amount of matter is extracted in the direction of the projectile motion. Dave -----Original Message----- From: Eric Walker <[email protected]> To: vortex-l <[email protected]> Sent: Tue, Oct 1, 2013 12:29 pm Subject: Re: [Vo]:Sound in a Vacuum Good point. That seems to imply that the energy developed within the bulk of the system at a wavelength for which the substrate is not transparent would be thermalized, e.g., into phonon modes, but probably incoherent ones. Eric On Tue, Oct 1, 2013 at 9:14 AM, David Roberson <[email protected]> wrote: Eric, I do not believe that IR can travel through a solid metal for a significant distance. Do you have reason to suspect that the energy can escape by that method other than when it is emitted at the surface? Dave -----Original Message----- From: Eric Walker <[email protected]> To: vortex-l <[email protected]> Sent: Tue, Oct 1, 2013 12:07 pm Subject: Re: [Vo]:Sound in a Vacuum On Tue, Oct 1, 2013 at 8:54 AM, David Roberson <[email protected]> wrote: The thermal power exiting each square centimeter of surface area is well within reason when 10 micrometer material is used and should not cause a meltdown according to preliminary figures. If the mass energy of the fusion events is delivered directly to the electronic structure, as I suspect it must be in order to avoid fast particles and gammas, I suppose much of that energy would radiate away in the IR and higher frequencies as conduction electrons fall back from excited states. The system could even become something like a large cathode tube, with electrons boiling off at the boundaries (because of all of the energy that must be dissipated). In this event, I have no idea how much of that energy would feed back into to the phonon modes. Eric
