Can a magnetic propulsion system be achieved

Earnshaw's theorem states that a collection of point charges cannot be maintained in a stable stationary equilibrium configuration solely by the electrostatic interaction of the charges. This was first proven by British mathematician Samuel Earnshaw in 1842. It is usually referenced to magnetic fields, but originally applied to electrostatic fields. It applies to the classical inverse-square law forces (electric and gravitational) and also to the magnetic forces of permanent magnets and paramagnetic materials or any combination, (but not diamagnetic materials). Earnshaw's theorem has no exceptions for unmoving permanent ferro-magnets. However, moving ferromagnets, certain electromagnetic systems, pseudo-levitation and diamagnetic materials are areas to which Earnshaw's theorem doesn't apply and thus can seem to be exceptions, though in fact these exploit the constraints of the theorem. 
Can we develop a safer cleaner transportation method that involves electro magnets that can propel cars using the city's grid to adjust the power on the street or road to move cars. similar to  famous movies vehicles like STAR WARS(c) Repulsor Lift(c) technology or The MATRIX(c) Ships OSIRIS?

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Sessha5 years ago
what about a dc motor with a few well placed electromagnets that constantly switch polarity to oppose a track of electromagnets on a exterior circle that also switch polarity according to the interior track + to - to + to - repeat repeat all that would be required is the initial spark correct then if done right could it not power it's self and possibly be perpetual until the parts wearout please don't steal my idea for military or selfish purposes unless you need to save life that would wear on the cricket in my head lol
kelseymh Sessha5 years ago
It's not perpetual motion. You must be supplying external power input to constantly switch polarity in order to drive the system. A system of static magnets like that is a well-known non-functional "perpetual motion" device.
Sessha kelseymh5 years ago
hmmm well maybe i'll get it right eventually my other idea is permenant magnets with mechanical triggers and spring levers to constantly flip the magnets but electromagnets i believe would generate more rpm
Qcks Sessha5 years ago
That system will still loose energy to heat.
Even though the train/vehicle hovers above the track, there's an electrical interaction between the magnets and the vehicle.
That interaction causes the magnetic elements of the system to increase in temperature. It's a bit like electromagnetic friction.

In some instances, this causes huge loses in efficiency. (like in electric motors.)

Train systems have an easier time because the magnets on the track don't need to constantly be in use and they have a chance to cool.
Thermal loses cause disorder in the magnetic vectors of the crystalline structure of the magnets.
Sessha Qcks5 years ago
still cooling the system sounds like such a small hurdle
kelseymh Sessha5 years ago
Try doing the math. Work out the eddy currents due to the moving magnets, plug in the resistivity of the metal, and use Ohm's law (P = I2R) to determine how much heat is being produced, which will tell you how much power dissipation (cooling) you will need.
Qcks kelseymh5 years ago
Kelsey,
I know why you're being defensive about this, but Sessha isn't being belligerent about it. I mean... maybe you didn't mean to come off harsh, but you did kinda. I'm guilty of that a lot, so i kinda understand. Just sayin.

Sessha, cooling systems are among the least efficient systems that exist. If running 1 volt through an electromagnetic coil causes a 1 degree increase in the coil, the cooling rig that removes that single degree increase can use as much as 10 times the energy to get rid of it (depending on the cooling rig used) as the energy that went into the thermal increase.

People each have their own ideas as to what's the best cooling system, and how you're constrained by your design matters.

While i dislike the Petroleum industry (they do actively interfere with technological innovation which would make them obsolete), there are solid reasons as to why we do things the way we do them.

Straight out, Electric motors are some of the least efficient motors on the market. The induced magnetic fields, which are what causes the movement in any electrical motor (AC or DC), cause alot of heat, even in copper.
Using permanent magnets doesn't change that, but you are correct in the idea that you can combine permanent magnets with cooling systems some what more easily then you can with more traditional electrical motors.
Do you ACTUALLY know what you are talking about ?? Modern DC drives are easily >>90% efficient.
Link one credible reference that shows that they have an electric DC motor that is greater then 90% efficient, and I will retract my statement. I've personally not seen anything credible stating any motor achieving greater then 80% efficiency, electric or otherwise.

Practically speaking, electric motors are more efficient then internal combustion engines, but it's because they don't have to idle to continue running, unlike an internal combustion engine (that is to say, an electric motor can turn off while not running).

Electrical motors show significant drops in efficiency when moving a load, and when they first start moving. That's ignoring adverse environmental effects and just paying attention to the effects of operation conditions.
Parker Traction motors make a good example

http://www.parkermotion.com/mobile/ParkerTractionMotBroch_WEB_4.20.10.pdf

Their headline figure is 95%, you'll see from the efficiency graph, the end to end efficiency doesn't droop below 85%.

Its not hard to find drives with similar characteristics

Your original claim that "electric motors are amongst the least efficient motors on the market" is just completely wrong, utterly wrong.
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