This is an interesting discussion Robin. I have worked with resonances for many years in radio design so I see parallel behavior. It is quite common to drive a system with frequencies that are below the resonance and obtain the driven response. You can start at essentially zero hertz and work your way up as long as you can figure a way to couple to the system. I believe we would agree that normal heating of a system of metal atoms results in their vibration at a random average rate. The magnitude of the vibration should be proportional to the temperature which is then proportional to the average kinetic energy of the atoms.
Until I considered what you just wrote, I had not given much thought to the coupling between the electrons in orbitals and the nucleus of the atoms. How tightly are they actually connected when in a metal crystal? I can see how it might be possible to obtain a very large Q if the nucleus is weakly restrained by the electrons. The spring analogy is a good one and it is interesting that you were able to obtain a spring constant equivalent for the mass to stretch and relax as it moves up and down, etc. How do you calculate a loss factor that damps the vibration? And, if the losses of each atom associated with the metal are very small, then there would be a lot of coupling occurring between nearby atoms. In radio design, you can reduce the actual coupling coefficient between two resonant tanks as the Q of each rises and still have the ability to transfer a large amount of energy between them. This is a common practice in band pass filter design. If the coupling between nearby atoms is adequate for the Q then we should see a large amount of energy being transferred in the vicinity of the resonances. That would be a good way to drive the metal into a frenzy. I am trying to visualize your explanation as to the difference between heat and sound wave movement in materials. I am not convinced that there is a big difference. Normal random heating must occur as kinetic energy and linear momentum is propagated into an adjacent region. Take as example the toy composed of hanging steel balls. Assume that they are a little separated in distance instead of physically touching. The first ball would hit the next one in the line and it would come to a complete stop while the new one continues with all the momentum and kinetic energy forward. This ball would collide with the next one on down the line. In this case the energy would move as fast as the beginning ball onward. Could we consider this as heat energy? I think so since it represents kinetic energy of the ball which could be scaled up with more of the same to represent a higher temperature. That simple model appears to clarify the issue. Notice that the energy and momentum was directed away from the source ball at a rapid pace which seems to far exceed what we normally think of as heat transfer. Now, I think that this is indeed exactly how it works. This is only one half of the system and the other half is energy being directed back towards the original heat source. How interesting. Now I understand why the thermal gradient is what drives the transfer of heat from a hot to cold region. The kinetic energy of the hot particles is continually being directed outwards and meanwhile energy is returning from the other direction. The hot regions sends a larger quantity of heat outward than it recovers and the difference between these two processes can be represented as the temperature gradient. Heat does not generally move at full speed as in the toy case because there are a multitude of balls(atoms) that share the momentum among themselves with collisions. The total momentum and kinetic energy moves outwards, but it spreads out into the total metal matrix and does not move as a strongly coordinated wave. Sound on the other hand is coordinated. For the toy analogy you can think of a sound wave as being the result of a surface containing a large number of the toys that are driven in a coordinated manner so that the motion continues with minimal spreading. In this case, the overall motion consists of parallel compression waves moving in one direction. Sound waves are thus coordinated in time and space while heat is not. Sound can therefore move at the maximum speed throughout the material while heat has to randomly spread forward which is much slower. Forgive me for the thinking process that proceeded as I was writing. Sometimes it is important to follow how a thought is formulated. I think this understanding I just visualized is a fairly good description of the physics behind the two processes. What do you think Robin? Dave -----Original Message----- From: mixent <[email protected]> To: vortex-l <[email protected]> Sent: Thu, Feb 28, 2013 8:24 pm Subject: Re: [Vo]:Explaining Cold fusion -IV In reply to David Roberson's message of Thu, 28 Feb 2013 16:44:14 -0500 (EST): Hi Dave, [snip] >Because it is just wrong! Kidding Robin. Now I am confused a bit, are you calculating that if I displaced an atom by a tiny amount and let go of it that it would begin to vibrate at that frequency as the energy damped out? Yes. >Maybe so, I was not thinking of that process. I assumed that you were >figuring out the vibrations due to the temperature of the metal. If what you calculated is accurate then an incoming photon of that frequency would easily be absorbed by one of the atoms and start it vibrating in place. Precisely. And heat has an appropriate frequency. Most sound waves OTOH do not. In fact they are "off" by many orders of magnitude. Hence my suspicion that this is the reason for the difference in speed between sound and heat in a solid. >Do you have any idea of how high the Q of the resonance would be? You might find that energy is stolen away by the nearby atoms quickly. I think measuring the speed of heat transport in the solid answers that question, since that's exactly what's happening when heat spreads. I.e. energy is transferred to other atoms. The Q must be pretty high, since the speed of heat spread is usually very low, except in metals where it is also spread by free electrons. > > >It would be interesting if you could calculate a similar resonant frequency >for the motion of just the nucleus. >Displace it slightly and allow it to wiggle back and forth within its electron cloud that is somewhat confined by the atoms surrounding it. 99.975% of the mass of an atom is in the nucleus, so this *is* essentially what I calculated. Since the nucleus is effectively suspended friction free in a mesh of electric fields (think springs), that explains why the Q is so high. >I wonder if a free atom in space exhibits a resonance of this nature? One might think that in free space that the electrons would compensate for the nucleus movement so quickly that it would immediately radiate the energy. [snip] Regards, Robin van Spaandonk http://rvanspaa.freehostia.com/project.html
