Interesting final question Eric. If in fact the heavy magnetic remains suspended then yes. On the other hand there is a mechanism that might result in the magnet being able to move slowly downwards through the tube. The complete system includes an additional loss factor associated with eddy currents flowing within the magnet body. The counter current flowing within the super conductor causes it to produce a magnetic field that penetrates the body of the permanent magnet.
If we assume that the magnet moves slowly within the tubing, then a current will be induced within the magnet itself that can convert gravitational potential energy of the magnet into heat. If this mechanism applies, which seems likely, then energy would be conserved as is required by the laws of physics. In the earlier thought experiment I was assuming an ideal model of a permanent magnet that has zero volume conductivity. A real world magnetic should slowly fall within a super conducting tube as the magnet converts its gravitational potential energy into internal heat energy. An interesting experiment would be to actually place a permanent magnet within a super conducting tube and see how it responds. If the magnet has zero volume conductivity, it will remain frozen within the small tube. On the other hand, if the magnet has current induced within its resistive body by the field originating within the super conducting tube, it will fall at some constant rate. Eric, we are conducting a thought experiment during this discussion instead of actually performing a real experiment. Unless all of the possible secondary effects are taken into consideration it is quite likely that the concepts need to be adjusted as real data is examined. When considering the above arguments, I do not agree with your last statement unless the heavy magnetic actually remains suspended and stationary within the superconductor. My thoughts are that this static arrangement is not going to be observed under real life circumstances. Dave -----Original Message----- From: Eric Walker <eric.wal...@gmail.com> To: vortex-l <vortex-l@eskimo.com> Sent: Sat, Nov 14, 2015 5:47 pm Subject: Re: [Vo]: How many atoms to make condensed matter? On Sat, Nov 14, 2015 at 4:26 PM, David Roberson <dlrober...@aol.com> wrote: So, I would expect to see the falling velocity of the magnet to become less and less as the conductor used for the pipe become less resistive. But, the geometry is also going to enter into the equation. Let's assume a geometry favorable to the suspension of the heavy permanent magnet for indefinite duration. If we assume that the pipe diameter is sufficiently small then it would make sense to assume that the magnet would be suspended at zero velocity if placed within a super conducting pipe. It's clear that with sufficient current in the superconductor, the heavy magnet will just sit there, with the force of gravity counterbalanced by the magnetic field that is induced. My question is whether the system is a stable one, or whether there's a gradual decrease in the current as a function of time. In one scenario, the heavy magnet is suspended in the superconductor indefinitely. In another scenario it is suspended there for a long time, until the current drops below a critical threshold, at which point it will move down a little, and so on, until it falls through. Just so I understand your argument -- is your understanding that the force of gravity does not indirectly counteract and do work against the current circulating in the superconductor as the heavy magnet is suspended there? Eric
