The reason I was asking was because I thought that if the forces are as Grassmann insists are perpendicular then removing the battery and instead using high frequency alternating current in what is now an open circuit should give rise to thrust.
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The force on the I's would be perpendicular with no force on any other segment.
However with further thought, the only way the above would fail to generate thrust is if the forces are as Ampere claims (longitudinal) without any displacement current in the vacuum between the two rails.
Even if Ampere is correct as long as there is displacement current the magnetic force from the vacuum displacement current would push on the rail in a longitudinal manner.
So Newtons law would survive as the equal and opposite force would be placed on the vacuum (aether).
If Grassmann is correct it doesn't matter if displacement current exists or not.
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By having the conductors diverge a bit more thrust might be created, but clearly the angle shown here is too steep.
Clearly I keep the 'rails' close and parallel to increase capacitance, I thought of increasing capacitance by adding capacitor plates to the rails (the two plates would of course remain the same distance apart as the rails) but realized as the currents branch out in the plates counter forces would be created, however if the whole thing were made of the same thickness that objection would be removed.
So wide ribbon would be the best material to use.
Horace Heffner wrote:
At 1:22 AM 4/4/5, John Berry wrote:
I'm not sure there is a single established answer to what I'm about to ask, but I know that both possibilities were at one time considered.
In a rail gun, clearly the force on the movable member is reflected elsewhere in the circuit, either as a longitudinal force on the rail, or on what bridges the other end of the circuit (generally the battery, which of course would have a force on it either way).
Is there considered to be a final word on if a longitudinal force is felt by the rails as a recoil? (and hence by the charge moving in the rail)
In other words are the forces at 90 degrees to the conductor, or not?
Here is an experiment that should answer the question, I think a form of this hairpin experiment has been preformed before.
------------------------------ *--------------------------- B I A Inner assembly moves as one I T *--------------------------- ------------------------------ stationary outer rails
Legend: - rail * contact point between both rails I transverse section that if this were a rail gun would be bullet
If a longitudinal recoil force is placed on the rails the inner assembly should barely move, otherwise it should move as with a normal rail gun and experience almost equal force.
Can anyone save me from preforming this experiment?
You need more detail in your analysis of this experiment. Even using Lorentz force (i.e. Biot-Savart) finite element analysis, this would be expected to work with the same net forces as an ordinary rail gun. The interesting thing you get from detailed finite element analysis is exactly where in the metal the forces arise.
For example, even if you expand your model just slightly, as in Fig. 2,
E C ------------------------------ | * | |W | ---------------------------- X B I A Inner assembly moves as one I T ---------------------------- Y | |Z | * ------------------------------ F D stationary outer rails
Legend: - rail * contact point between both rails I transverse section that if this were a rail gun would be bullet
Fig. 2 - Expanded detail of armature bends
then, from a bit of experience, you can see the large (but seen oly in finely detailed analysis) Lorentz self-forces in the metal at current bends X and Y exactly cancel the self-forces at current bends W and Z. This then leaves the ordinarily ILB force on the armature of length L due to the force of field from the the rails on segments C-W, and D-Z, as well as the forces from the fields from segments W-X and Z-Y on segment X-Y, and the total length L is still C-D.
There ILB force at the battery end is equal but opposite to the ILB force of the armature, so the primary "recoil" takes place at the battery end, unless there are bends in the rails prior to the battery.
Note also, that there are indeed longitudinal forces in the rails however! The cause of this can be seen only when analysing the current bend areas inside the rails near the arc points, i.e. points C and D, with fine granularity. A Loretnz self-force arises there that matches the internal self-forces in the bends at the battery end at points E and F. These forces are opposed, so there is a tensile force on the rails between E and C, and also between F and D in Fig. 2. If the rails are heated to the point of melting at the arc point the the rails deform permanently as the armature moves along and the the rail ribbons. If the rails are laterally restrained then the internal laterally directed Lorentz forces compress the fluid rails in the forward direction in the segments slightly leading the armature. As the armature moves the hot segment is thus subjected to compressive force followed by a stretching force. The resulting rail deformations give the appearance the primary recoil force is in the rails near the aramture, thus giving credence to amperian current segment analysis vs Biot-Savart, and giving rise to hopes for inertial space drives. In my experience with this stuff Biot-Savart always wins.
Another way to look at the circuit is to pretend the arcs dont exist. Weld the gaps shut. Now, if bending the armature in some way increased the forces on the armature's current segments, without creating an equal but opposed set of forces in the other part of the circuit, then you would have a closed cirucit inertial drive. The sum of the forces about a closed DC circuit are unfortunately zero.
It never hurts to experiment though. Nature doesn't always agree with theory.
Regards,
Horace Heffner
