>> We create a torroidal magnetic field and rotate it
>Whoops your gedanken just jumped the tracks. You *can't* rotate a field.
>You can rotate an object. You can rotate a frame of reference. You can
>rotate your head trying to follow an obscure argument. But you can't
>rotate a field, nor move it, nor do anything else which requires
>"pushing" on it because you can't get a grip on it.
Well, I have had to think long and hard
how I want to respond. I really didn't want to get tied down as to
the engineering of how one would produce such a field. But I do get
your point, something must produce the field. If we were to take a
bar magnet and rotate it at relativistic speeds, obviously it would
fly apart. And yet it still seems that we should be able to imagine
such a magnet that does not fly apart for the purposes of a thought
experiment. We could talk about a stepper motor type configuration,
but I think there would be question as to whether we are actually
rotating a magnetic field or producing multiple fields that are
phased in such a manner as to rotate another field (no, I'm not sure
I said that right). And then there is the ultimate question of what a
magnetic field is - and I'm not talking about the mathematical
description of it.
I have read - can't remember the source,
and I'm probably butchering it - that all of physics is geometry.
That is to say that once we understand all of the forces, they will
be reduced to geometry. I don't know if you agree with this or not,
but I do believe this will be found to be true. So there is the
question as to whether magnetism is a property of the geometry of
space-time itself. Yes, something does seem to be required to modify
space-time in such a manner as to produce magnetism, but is that
magnetism a property of that which produces it, or a property of the
geometry of space-time itself? I say it is the result of the geometry
of space-time itself. As such, I argue that the magnetic lines of
force are "physical" and can be rotated relative to an
outside frame of reference, and the thought experiment is valid.
But
I suspect you will insist that we must consider that which is
producing the magnetic lines of force. Ok, I will try. But I am not
an engineer, and know there are those much smarter than me that could
engineer such a device. So I do this with the hope that the physics
involved can be discussed and not my bad engineering skills. But, I
will be brave and take a shot at this.
First, there is no
solid physical object that we could use to produce such a field and
have it survive the centrifugal force involved when rotating at
anything even close to relativistic speeds. We could use a stepper
motor type configuration to create rotation of another existing
magnetic field, but anything creating that field would also be
subject to the same forces. So, we must look elsewhere. So my
solution is to look at a plasma. We can create a rarefied plasma and
align and rotate the magnetic domains in that plasma. I would
suggest an inert rarefied gas be used that is ionized, perhaps Xenon.
The ionized gas would be in a column.
To align and rotate the magnetic
domains we would use RF signals injected around the outside of the
column, with the phases of the signals being shifted in much the same
manner as a stepper motor. The RF signals injected would at first be
of a low frequency and then be increased in frequency. The RF signals
themselves would be produced by Back Wave Oscillators and Traveling
Wave Tube Amplifiers, perhaps in a push-pull configuration. I do
realize that there may be issues with harmonic oscillations that
would need to be addressed.
As the field begins to rotate I would
expect it to want to collapse inward, so I would have a toroidal
shaped shell made of Bismuth, a strong diamagnetic, that would
surround the core with the purpose of forcing the magnetic lines of
force outward and preventing the collapse of the field.
Ok, that is my best shot. I'm sure I
left out many details. In the end we are talking about rotating the
magnetic domains in a plasma with RF signals to produce a magnetic
field that is rotating relative to an outside observer. Will it work?
I don't know, but I suspect that even if what I have described does
not, someone smarter than me can think of how one would produce such a
relativistic magnetic field.
So, assuming such a field can be
produced, would there be time dilation effects inside the field?
Would the field acquire inertial mass because of the relativistic
effects? Would there be a change in gravitational mass? If a
radioactive isotope were placed inside the field, would an outside
observer detect any change in the rate of decay?
C. Michael Crosiar
>A so-called "traveling" field, like EM radiation, is a field which
>disappears at one point and appears at another point. If you look at
>the equations, and think about what they're telling you, that turns out
>to be the only thing they're saying -- there is nothing in there about
>the fields actually "moving", nor about the "velocity" of the field
>itself. The things that move are the maxima, minima, nodes, and
>accompanying values. The field itself just kind of "is".
>But in your gedanken, you're rotating *something*, even if it's not the
>field. So, let's back up and ask exactly what you *are* rotating.
>Rotation is physical, so you must rotate a physical thing. So, what
>physical thing are you thinking of rotating?
>Spell that part out and we can take it from there, and the whole thing
>will make much more sense, I'm sure.
>> at relativistic
>> velosities, such that the inside of the torroid would be rotating at near
>> the speed of light. The outside of the field would extand outwards and would
>> have an agular velocity that would be greater, proportional to the increase
>> in circumference. First, is that correct? Clearly nothing can go faster than
>> the speed of light, but as we increase the speed of the rotation, the energy
>> must go somewhere, yes? Would this cause the mass of the field to change? In
>> other words, would it bend space-time inside the field? And could the
>> curvature be negative or positive depending on the direction of rotation
>> relative to the N/S pole? Would time run at a different rate inside the
>> field versus outside the field? If we were to place a radioactive isotope
>> inside the field, could we cause it to decay faster or slower?
>>
>> I'll be anxiously awaiting your insights,
>>
>> C. Michael Crosiar
>>
>>
>
