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Could magnetism just be explained as a relativistic effect ?


sally

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Ampere's Law is Just a "Relativistic Charge Effect"

****************************************************

 

Magnetism is not a real force and does not really exist.

Magnetism is just as Einstein had stated a "relativistic

effect " of common charge.Magnetism is the result of the

movement of charges.

 

 

If we assume that

 

Charges increases with velocity

**************************************

 

we can explain all static magnetic effects .

 

Instead of using field with right-hand rules we can directly have a look

 

at the forces that charges have on each other.

 

 

 

 

 

 

 

 

A simple equation

 

 

 

q=q0+1/2*q0*v^2/c^2 (1)

 

 

with Coulomb's Law is enough to describe Ampere's law.

 

 

Thus magnetism is just a charge effect.

 

 

 

This equation is the equivalent of Einsteins relativistic mass

equation

 

m=m0/(1-(v/c)^2)^.5 (2)

 

 

 

 

Equation 1 is just the approximation of Eq.3 when v<<c .

 

 

 

 

Gettting Ampere's Law from "Relativistic Effects"

*************************************************

 

 

q=q0+1/2*q0*v^2/c^2 (1)

 

 

The second term over here is what we call magnetism.The

imballance of positive-negative charges caused by the

moving current create a force which we call magnetism

(ie. the magnetism as defined by Amperes Law. There are a

few types of magnetism which are not all the same.).

 

 

 

 

 

We can now derive Ampere's law which is one half of Maxwell's

equations dealing with magnetism. We have our two parallel

wires with the current moving in the same direction . We will

now calculate the forces between the wires.

 

In a way similar to Purcell we calculate the four sets of

charges the positive-positive , positive-negative,

negative-positive and negative-negative.

 

 

 

F_total=F_pp+F_pn+F_np+F_nn

 

 

 

In order to calculate the "relativistic charge" we just need

to note the relative speeds between the charges . The positive

charges do not move w.r.t. each other and so the velocity is 0.

We will not have a "relativistic effect".

 

Likewise the negative charges move at the same speeds and have

no "relativistic charge effect".

 

 

The two sets of negative-positive charges move and so increase.

The ballance of the forces is thus attractive.

 

 

 

The calculations are as follows ;

***********************************

 

F_pp=-K*q1*q2/r^2

 

 

 

F_pn=K*q1*q2/r^2+K*q1*1/2*q2*v2^2/r^2/c^2

 

 

 

F_pn=K*q1*q2/r^2+K*q1*1/2*q2*v2^2/r^2/c^2

 

 

 

F_pn=K*q1*q2/r^2+K*1/2*q1*v2^2*q2/r^2/c^2

 

 

 

F_nn=-K*q1*q2/r^2-K*1/2*q1*q2*(v1-v2)^2/r^2/c^2

 

 

 

 

Thus if the two currents are in the same direction we

finally get

 

 

 

F_total=K*q1*1/2*q2*v2^2/r^2/c^2+

K*q1*1/2*q2*v2^2/r^2/c^2-K*1/2*q1*q2*(v1-v2)^2/r^2/c^2

 

 

 

or

 

 

F_total=K/2/c^2*q1*q2/r^2*A

 

 

 

where

 

 

A=v1^2+v2^2-(v1-v2)^2

 

or

 

A=2*v1*v2

 

 

 

Thus

 

 

 

F_total=Km*q1*q2/r^2*v1*v2

 

 

 

where Km=K/c^2 the magnetic constant

 

 

 

as I1=v1*q1 and I2=v2*q2

 

 

 

F_total=Km*I1*I2/r^2

 

 

 

Integrating etc. to get the total force between the two wires we get

 

 

 

F_total=Km*I1*I2/r where positive is towards the other wire.

 

 

 

 

***************

 

Similarly if the currents go in opposite directions we will find the

two wires will repell one another .

 

 

Over here the two negative charges move at double the speed

w.r.t. each other compared to the negative-positive charge

flow. The unbalanced force between them is four times that

of each of the positive-negative charge flows.The result

is the wires will move appart.

 

 

F_total=-Km*I1*I2/r

 

See

http://uk.groups.yahoo.com/group/DynamicFT/

 

*******************

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What is the purpose of your post? Proving that magnetism is related to charge? I see this stuff enough in class! :P

 

 

Everyone who knows a little about magnetism knows

 

Einstein's explication that magnetism changes

 

with velocity and can be "considered" a relativistic effect .

 

 

I go a further and say magnetism is only a relativistic

 

effect of relative charge movement . Einstein seems to hold that

 

even so magnetism really exists but could change with relative frames.

 

 

 

I claim magnetism does not exist . What we call magnetism

 

is just a calculation aid . There is no such thing as magnetism

 

or a magnetic field .

 

 

 

The relativistic charge effect is or at least

 

can be considered as an increase in charge defined by

 

q=q0/(1-v^2/c^2)^.5 in exactly the same way as Einstein explained

 

mass increases.

 

 

 

 

 

This effect can be used to calculate the direction of the forces of magnetism.

 

It can be used in a way that is more direct and simpler than fields

 

and the right hand rule .

 

 

 

 

Why use a complex indirect system when you can use one that is direct.

 

Magnetic fields do not exist . They are only a means to describe certain

 

effects . What is really happening is the forces between charges .

 

 

Magnetic fields and magnetism are just an historical anomaly from

 

before Einstein.We do not really need them in our theories or calculations.

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How do you describe the magnetic moment of a stationary point particle, such as the electron?

 

There would also be geometric issues, like configurations where a torque is exerted, that cannot be explained solely by the electrostatic interaction.

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How do you describe the magnetic moment of a stationary point particle' date=' such as the electron?

 

There would also be geometric issues, like configurations where a torque is exerted, that cannot be explained solely by the electrostatic interaction.[/quote']

 

 

For the electrons I think that some type of solution can be found . It could be that they are a circular standing wave that gets smaller at higher energies .I somehow feel that a simple

solution exists for electron spin as well .

 

In the Stern-Gerlach experiment I have two ideas . I have not yet gone into all the details

but here are the main lines .

 

1.The Corkscrew Approach.

********************************

A moving electron does not move in a straight line but corkscrews forward.When the

electron leaves the magnet it will be deflected slightly differently depending whether

it right-turns or left-turns.

 

 

2.The Flying Pancake Approach.

****************************

The electron is a circular standing wave . When the electron enters the magnetic field it

gets polarizes horizontally .From the top it either spin around clockwise or anti clockwise.

When it leaves the strong magnet it will not be diverted in the same way for the two

spins.

 

******

 

 

What kind of torque are you talking about ? Torque of the electrons themselves or

torque in electric motors ?

 

 

If you are talking about the torque of motors it can all be explained by means of the

"relativistic charge" . :D :D

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Maybe I see what you are seeing, drawing on paper one charge passing by another. If they are like charges, the magnetic effect pushes them away. I don't see what your four-charge calc involves. You have nicely alarmed me. Minds like yours are dangerous. How does a circular field such as I describe (A-sub-phi) Lorentz transform? Does your effect work in the longitudinal direction? Looking at charges approaching each other straight on, isn't magnetic interaction zero (neglecting spin)? Do you need to dial up a transverse L-transform?

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1.The Corkscrew Approach.

********************************

A moving electron does not move in a straight line but corkscrews forward.When the

electron leaves the magnet it will be deflected slightly differently depending whether

it right-turns or left-turns.

 

 

2.The Flying Pancake Approach.

****************************

The electron is a circular standing wave . When the electron enters the magnetic field it

gets polarizes horizontally .From the top it either spin around clockwise or anti clockwise.

When it leaves the strong magnet it will not be diverted in the same way for the two

spins.

 

In both cases you've got the electron spinning like a top' date=' but this view of spin was abandoned long ago for some very good reasons. For one thing there is the behavior of spin 1/2 particles under [imath']2\pi[/imath] rotations: the wavefunction picks up a negative sign. You have to rotate an electron through [imath]4\pi[/imath] radians to get back to the initial state. That's clearly not ordinary rotation!

 

The fact is that there is no acceptable description of electon spin that relates to our ordinary concept of motion. So the magnetic moment of the electron really is a counterexample to your claim that all of magnetism is just a consequence of moving charges.

 

Erm... it is well know that magnetism is a relativistic effect (an electric field in one reference frame is a magnetic field in another). Are you trying to say something new?

 

I know you know this for everyone else: An electric field in one frame is a magnetic field and an electric field in another frame. You can't transform away a pure electric field entirely, and neither can you transform a pure magnetic field entirely.

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Maybe I see what you are seeing, drawing on paper one charge passing by another. If they are like charges, the magnetic effect pushes them away. I don't see what your four-charge calc involves. You have nicely alarmed me.

 

 

Sorry about the way I write the equations but I have not worked out how to display the \math.

 

The main equation I use is

 

q=q0/(1-v^2/c^2)^.5

 

This equation is exactly the same as the relativistic mass equation with the mass

replaced by the charge.

 

 

Please take carefully note !!!!! The velocity over here is the velocity between the

two sets of charges and not the charges w.r.t. us.

 

At low velocities this simplifies to

 

q=q0+.5*q0*v^2

 

See http://hyperphysics.phy-astr.gsu.edu/hbase/electric/miccur.html

for the velocities involved .

 

For electricity we only need this equation as v<<<<<c .

 

 

Purcell uses a slightly different approach based on length etc.You can have a look

at http://physics.weber.edu/schroeder/mrr/MRRtalk.html for more details. I am not

too sure that all the details would work .

 

If we assume that charge increases with velocity it becomes much simpler.

 

 

To start of in a wire we have the positive charges the protons and the negative the electrons.We have to calculate the sum of all the forces between all the charges

in two wires.

 

ie positive_1 to positive_2

positive_1 to negative_2

negative_1 to positive_2

negative_1 to negative_2

 

 

If we take carefull note there is no electrostatic charge . If the there is no current in

one of the wires there is absolutely no force between them . "Magnetism" is the

unbalance of the charges. The forces involved are so extreme that even a tiny

unbalance is a giant force .

 

In order to see that this is true you really have to "break your head" and work out all

the gory details. Its really difficult after centuries of using the inverse-backward

positive-current-magnetic approach.

 

With this Ampere's Law becomes much clearer . Magnets , electromagnets , motors

and the hall effect all become clear .

 

The Hall effect !!!!!

 

Yes .... Don't tell me that with the classical approach you really understand why

positive charges or holes give an inverse current to electrons :D :D :D :D

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Sorry, I was pulling high vacuum for a while there. Consider a conductor pair, or even twin plasma streams of opposite current. Such a pair is mutually repulsive. Now what if we recreate one of the currents by the opposite species moving the opposite way? This yields the same magnetics, no? They are different in charge relative sign now........You have to be careful looking at individual charges, and this is where I got into trouble earlier.

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Are you sure that two plasma streams have a magnetic effect ?

 

A simple calculation of the forces involved would show that the Coulomb forces are

in the order of c/v times as strong as any magnetic forces .For plasma it would be

extremely difficult measure it .

 

Just to get you a bit giddy with the forces involved ;

 

 

Let us take my two wires of cross section 1mm and length 1m at 1cm from each other

We will let 1 amp of current flow through it .

 

Volume of Wire mm^3 1000

Volume of Wire m^3 1e-6

Number of free electrons in copper /m^3 8E+28

Total free electrons in sample in 1 wire 8E+22

Charge of an electron Coulombs 1,6e-19

Total charge 1,4E+10

Coulombs Constant N.m^2/C^2 9,8E+9

Total Force at 1cm in Newtons 1,8E+34

 

For 1 amp flowing in these two wires the magnetic force is 100 N (Ampere's Law)

Thus the Electrostatic force between only the free electrons in the wire is 2E+32

times the magnetic force .

 

Magnetism is just a tiny , tiny dishamony between the enormous forces in the wire .

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Your answer is enlightening but not convincing. True I use an awkward example of non-neutral currents. Do you agree that a wire pair of which one is return current mutually repel? I restring pianos and what if I could come up with an antimatter wire conductor? I save some very old scraps! I will go through your calcs; this is cool. I feel lucky to be alive, actually. Twice I have been within half a block of shorted main electric distribution wires, and they do an ugly dance. Have you ever witnessed this? I thought I was about to die, slammed my car into reverse, and trembled for quite a time.

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What emergence and what sytems?

 

That's another way of saying "The whole is greater than the sum of the parts," i.e. a system of parts can have properties which do not exist in the union of the set of properties its component parts have.

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I agree, in general, but question whether your philosophizing is useful here. I am starting to see that magnetism at least in a steady state implies necessarily two motions, one of the source and also of the 'responder'. You are putting in this information; how do you expess it clearly? A stationary charge with another passing by experiences no transverse magnetic force. I think it is true, though, that it experiences a lateral shift. Look at momentum being [math]qA[/math], and realize [math]A[/math] is lateral. This says that as the moving source approaches it pushes a like charge magnetically, but then pushes back after passsing to cancel the delivered momentum, and this all in the lateral direction. Don't you have to put in geometric knowledge to eliminate an unwanted transverse force? Or have you cleaned this up by being in a certain frame of reference, like center of mass for two particles? It is not so useful to describe physics in a preferred frame of reference. If you use Lorentz transform all of your physics must be transformable. . . . . . . . . . . . . . These thoughts bring me to an interesting question. Can we simply start with Maxwell's eqs. compared between two reference frames and in a few steps produce special relativity? It is buit in, it seems. If we go to the center of mass frame there is magnetic 'field' from both sources where in the first stationary frame there was not. Is this how Einstein et.al. got to it? I thought it was more of an act of writing the Lorentz transform to cover implications of Michelson-Morley. All roads lead there but around the year 1900 folks did not enjoy our hindsight which includes construction of the Minkowski tensor.

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Einstein And Magnetism

******************************

Einstein already found that magnetism is just a "relativistic" effect of charge.This only applies to stable or variable magnetic forces such as those desribed in Ampere's Law.Faraday's or Lenz's magnetism is different and requires another fascinating approach.

 

This was already a big step but Einstein did not go all the way to show us that it could actually be used and that it is actually much simpler than Ampere's law to apply and use.

 

No longer do we need abstract fields and "Kabalistic" right hand laws.We can now actually understand what we are doing,why we are doing it and work in a simple,direct way.Charges act directly on other charges.

 

Ampere's law can be stated as

 

[math]

q=\frac{q0}{\left({1-v^2/c^2}\right)^{.5}}

[/math]

 

q0 is the rest charge

v the relative velocity between the charges conscerned

q the resultant charge.

 

or if v<<c (All normal electricity) this becomes

 

[math]

q = q0+\frac{1}{2} {q0} {v} ^2

[/math]

 

With this simple equation we can ;

Calculate and derive the force between two or more electric wires

Calculate and clearly see how motors work

Derive the Lorentz charge equation or calculate simply and directly the forces on a moving charge in a "magnetic field"

Calculate the forces between magnets

Calculate the forces of electromagnets

Derive the forces between magnets and currents

Derive the Hall effect and see clearly why positive holes yeilds opposite voltages.

 

And the cherry on the cake...

The Lorentz transformation becomes a piece of pie !!!!

 

All this was stuck on the moustache right under the nose of a certain absent minded professor called ....

 

But now instead of philosophizing the proof of the pudding is in the eating.

 

It really is simpler and easier.

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