This is a electromagnet with a spring attached at the bottom that is made of a material whichis not affected by the magnetism. At the bottom of the spring is a piece of metal which is affected by the magnetism. In theory the electromagnet should pull the piece of metal toward it causing the spring to push up against the magnetic without a opposing force thus creating momentum in the upwards direction which can be designed to be used as a propulsion system.
Can anyone find a flaw with this?
Reactor,
I'm not sure if I understand your design so I'll describe what I think you're trying to do and see if I have it correct:
You have an electromagnet with a spring attached to the "bottom". To the opposite end of the spring you have a piece of iron (or some other ferromagnetic material). This is a magnetic propulsion "engine". The system itself is not attached to anything and is free to move if a force is applied to it.
The spring starts out in its minimum energy state - uncompressed. You power up the electromagnet and it attracts the iron plate which in turn compresses the spring as the plate moves toward the magnet. The spring therefore stores the magnetic energy as potential energy. You then turn off the magnet which allows the spring to uncompress and release the potential energy as kinetic energy. This causes the magnet end of the engine system to move forward ("up" in your case). You then repeat the cycle, each time adding to the velocity of the system. Its a pulsed propulsion system.
Is this basically correct?
If this is correct then, no. It won't work as a propulsion system. I won't give a rigorous analysis because we don't have time to get a degree in physics here
just to answer the question. But the answer as to why it won't work is found in a combination of Lenz Law, Hooke's Law, Maxwell's E&M equations and Newton's laws of mechanics regarding reversible processes. The basic answer is there's no free lunch, i.e. momentum is conserved in a closed system harmonic oscillator such as what you propose.
When you turn on the electromagnet the spring will compress...from both ends...simultaneously. There could be a net delta
v and delta
p (change in velocity and momentum depending on several factors including the relative inertial mass of the objects, the strength of the magnet, the length of the compression, the time that it took to compress,,,one end could have a greater net change in velocity than the other) for the system during the compression half-cycle. The magnetic energy will be stored in the spring as potential kinetic energy.
When you power down the electromagnet the potential energy is released as kinetic energy as the spring uncompresses and completes the final 180 degrees of the cycle. This is the time reversed process of the first half of the cycle. The sign of every force applied in the first half of the cycle is now reversed. These forces result in delta
v and delta
p that are exactly the same as in the first half of the cycle but signed negatively, The system will then be returned ito its initial state with no net change in
v or
p. I suggested above that there might be a net change in velocity depending on several factors. THose factors are still in play as the spring uncompresses. The two masses don't suddenly stop when the spring is returned to its initial state. The ends have momentum and they now stretch the spring. The spring eventually absorbs their momentum. The point where that occurs is simultaneous with the time that the initial net velocity is completely reversed. The system is now moving in the opposite direction with the same but opposite velocity as was imparted in the first half of the cycle.
Repeat the cycle. It's a wash. The system will basically oscillate about its initial point. In the real world there will be a random change in total momentum because the real system is not idealized and there are energy "leaks" in the form of heat, sound, light, etc. In other words in every reversible closed mechanical system like this there are internal thermodynamic processes going on that are irreversible.
I think that what you'll actually see is that the real world system will want to spin rather than translate (move linearly). A real system isn't idealized (prefect in every aspect) and the vectors of the impiulses will not be precisely opposed. There will be some misalignment resulting in a spin vector.
Also, real springs which are subjected to the sort of constant forces implied n your system that aren't rigidly held in place and cooled quickly heat up and lose their spring qualities. But that's an engineering problem and not a basic physics problem.
Note:
v and
p above are in bold text to indicate a vector quantity - magnitude and direction.
