0
$\begingroup$

Let's take Faraday's experiments of induce emf where He take a loop and a magnetic field, for instance let's suppose we have an coil and a magnet, Now If we move the magnet towards the coil there will be an induce electric field and Thus the force $\vec{F}=q\vec{E}$ on charges of loop and thus the induce electric field but Now suppose I'm in frame of reference that is moving along with magnet with the same velocity as the magnet so that magnet is rest in my frame but coil is moving, in this case I will say charge in coil is moving in magnetic field and thus there is an Lorentz force $\vec{F}=q(\vec{v}\times\vec{B}) $ and thus the induce emf. So How the same phenomenon is explained from two different Frame of reference with two different principals? Or my reasoning is wrong? Is it possible that a same phenomenon( as here) In general, Can be explained with two different principals from two different frame of reference?

$\endgroup$
0
$\begingroup$

Your reasoning is actually right! And it is one of the key arguments that brought Einstein to formulate the special theory of relativity.

In the context of special relativity, the transformations that links two different inertial frames of reference (IFR), are called the Lorentz transformations, and it happens that a phenomenon described by an electric field in one IFR, is described by a magnetic one in some other IFR.

My answer is more of a hint rather than a serious and detailed explanation that you can find in every textbook that treat special relativity. I suggest you in particular the chapter Electrodynamics and Relativity of Griffith's Introduction to Electrodynamics, where he starts right from this "duality" of electrodynamics (i.e. same phenomenon, two different physical origin in two different IFR).

| cite | improve this answer | |
$\endgroup$
  • $\begingroup$ So what's the reality? $\endgroup$ – Young Kindaichi Jan 28 at 18:22
  • $\begingroup$ The "reality" is that the event you observe, happens and is the same in every FoR (frame of reference) but the physical cause may somewhat change (electric or magnetic). In a more fundamental view, the magnetic and the electric fields, are no distinct objects, but rather, their components form a single object, namely a 4x4 antisymmetric tensor called the electromagnetic tensor. In this way you can see that what you call electric, or magnetic field are actually the components of a tensor, and as every tensor...[continue in the next comment] $\endgroup$ – zkanego Jan 28 at 19:42
  • $\begingroup$ ...his components change under a coordinate transformation and it may happen that some of them vanishes in some particular FoR. However, the tensor itself does not change under a coordinate transformation, but just his components that we "naively" picture as separate distinct objects. You can make an analogy with a vector, when you rotate the FoR, the vector doesn't change, but his components do. If you give a physical meaning to the vector, his components are what you measure. In some FoR it may happen that it has no x-component altough it is always the same vector. $\endgroup$ – zkanego Jan 28 at 19:42
  • $\begingroup$ Thanks So it means that the quantities we learn so far may uninvarient through Lorentz transformation but there may be some quantities that must remain invarient. $\endgroup$ – Young Kindaichi Jan 29 at 2:17

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service, privacy policy and cookie policy

Not the answer you're looking for? Browse other questions tagged or ask your own question.