Naked Science Forum

Non Life Sciences => Physics, Astronomy & Cosmology => Topic started by: rocking_1987 on 02/08/2012 04:57:52

Title: Can we manipulate the electric and magnetic fields together?
Post by: rocking_1987 on 02/08/2012 04:57:52
Hi,

I have two questions.

The first question is this,

We know that electric-magnetic field can be created by manipulating any one of the field.

Can we manipulate both at the same time? I mean what will happen if i want to move copper wires on its horizon as well with the magnets moving around it? What kind of difference can it make in the electricity production?

For more clarity,

Lets have one copper wire and lets move the magnets around it. It should create the electricity. Now lets move the copper wire on its horizon with the help of the another electric magnetic system.

The second question is this,

Can we join the two electric magnetic systems (lets say system a and b) in a way that can manipulate each other directly? I mean change in A system's electric production will increase the speed of the B system's magnets and vice versa. The increased speed of the magnets of the System B should increase the electric production to some extent and that electricity will be used by the system A's copper wire core to move on its horizon.

I wish you may understand what i want to say?

Thanks
Title: Re: can we manipulate the electric and magnetic fiels togethar?
Post by: CliffordK on 02/08/2012 06:31:33
I'm not quite sure what all you are imagining. 

Some generators, for example most of your automotive alternators use field coils which must be powered to create a magnetic field to induce current in the stator assembly.  Thus, when you turn an alternator without it being connected to a battery, it spins quite freely.  And, in fact, an alternator can't be used to push-start a car with a completely dead battery (an old fashioned generator can theoretically generate enough power to push-start a vehicle with a dead battery).

Some generators have permanent magnets that will induce current in the stator assembly.  These are usually the most efficient types of generators.  However, to make them compact, some will have both permanent magnets and field coils to increase the strength of the magnets, and thus increase the power generation (while still generating power from zero).

The main advantage of the modern car alternators without the permanent magnets is that they freewheel when no power is required. 

A transformer can take AC power at one voltage, and using two coils of different sizes, induce a different voltage (higher or lower) in the secondary coil by utilizing the difference in magnetic fields between the primary and secondary coils (with a corresponding change in amperage).  It requires AC, because, like an electric motor, it requires changing magnetic fields.

I have seen coupled rotary phase converters that have two electric motors connected together to convert phases.  However, I believe that in many cases this is now more frequently done using solid state electronics. 

There is also some way to create a rotary phase converter with a single 3 phase motor, in which one feeds in single phase 220V, and gets out 3 phase current sufficient to run other 3 phase motors.
Title: Re: can we manipulate the electric and magnetic fiels togethar?
Post by: wolfekeeper on 02/08/2012 16:26:33
An aerial is a device that creates magnetic and electric fields at the same time.

When you do that, you create a radio wave that radiates away and can be picked up many kilometres away.

If you just generate a magnetic field or an electric field then no radio waves are created.

Aerials usually do this by having alternating currents flow down to the tips of a wire; the tip charges up to high voltage, and the middle of the wire carries the current to do this, and this generates the magnetic field.

That's why the aerials on roofs have lots of sticky out rods, that's what they do!
Title: Re: can we manipulate the electric and magnetic fiels togethar?
Post by: evan_au on 05/08/2012 12:07:18
The question seems to be asking about a perpetual motion machine, or perhaps electromagnetic propulsion.

As soon as you make a wire out of copper, you lose energy to resistance, which gets turned into heat. (Superconductors are better, but in our part of the galaxy, it takes large amounts of energy to keep superconductors cool.)

It takes large amounts of energy to create a magnetic field - and it's very hard to direct the magnetic field exactly where you want it. (Again, superconductors are better, but they don't work so well with rapidly changing magnetic fields.)

As soon as you have movement in a system, you start to lose energy to friction and eddy currents, which produces heat. This may work in space, where there is less friction.

Linear electromagnetic propulsion works, but one part of the machine has to exert a force on another part, upon which they tend to fly apart, in which case it is no longer one machine.

It may be possible to create a static machine such as described, out of superconducting materials, and constructed far beyond the orbit of Pluto so it can be naturally superconducting. But as soon as you attempt to extract any energy out of it, it will stop.
Title: Re: can we manipulate the electric and magnetic fiels togethar?
Post by: yor_on on 09/08/2012 15:10:51
You can move the wire, you can move the magnets. Both ways you should get out a EM field. You can move both against each other too, and that will produce the same, but the effort  (work)  put into moving both can never be less than the EM you get out. At least as I know.
==

What I mean is that you can't get 'energy' from nothing. To create a EM field you have to put in some work, or tap it from something else, and the idea of getting more out of it than you (and the universe) 'put in' is a dream still to be realized. Even 'zero point energy' assume that you somehow tap from something that must be 'transformed' as I think of it. There is no 'free lunch' in the universe.
=

Think of this way, the universe have a 'energy'. That 'energy' we can transform into a lot of things but to assume that you can get more 'energy' out of the universe than what there is? If that was what you meant? But yeah, we might be able to transform more than the 'work' we put in ourselves, so maybe?
=

Although there is still one thing I'm wondering about, but it primary concern what we mean with 'information'. If I measure a entanglement I will put in a 'energy' in the entangled system, and if a entanglement is the 'exact same' at both ends that energy must become duplicated in the measurement of one. That one seems to implicate that I by doing my measurement also 'transport' energy to the opposite end of the entanglement. So, does that 'energy' represent some sort of information? If I could do it over a lot of atoms, all entangled? Drive my car by it :)

And where will the surplus 'energy' at the opposite end come from? Or will the energy I put in one end only represent half of the energy put into my end of the 'system'? No, that's not possible (or could it? That would go against all I know here, but?) so it must be so that all measurements should 'tap' more 'energy' than what I put in measuring at my end of the entanglement. And if you don't find that thought provoking :)