Maxwell's EM Theory vs Principle of Relativity

In summary: Einstein's initial triumph was to re-derive the Lorentz transforms, starting from just the Principle of Relativity and the assumption that the speed of light is the same in all inertial reference frames, and to show that they could apply to everything (not just electromagnetism) and to explain how we had missed that fact. Nasty run-on sentence left into highlight just how broad this success was.
  • #1

HAF

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What was the problem between Maxwell's EM theory and the principle of relativity? Why went the theory against the principle?

I understand that the EM theory says that Light was a wave and ether is it's medium.

On the other hand the principle of relativity says that there is no state of absolute rest.
 
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  • #2
HAF said:
What was the problem between Maxwell's EM theory and the principle of relativity? Why went the theory against the principle?

I understand that the EM theory says that Light was a wave and ether is it's medium.

On the other hand the principle of relativity says that there is no state of absolute rest.
There is no conflict between Maxwell’s theory and the principle relativity. In fact, it is the prime example of a relativistic field theory.

The conflict is between EM theory and Galilean relativity, in which all speeds change under transformation between inertial frames.
 
  • #3
Orodruin said:
There is no conflict between Maxwell’s theory and the principle relativity. In fact, it is the prime example of a relativistic field theory.

The conflict is between EM theory and Galilean relativity, in which all speeds change under transformation between inertial frames.
If I understand it correctly then light's speed is not changing and that's against the Galilean relativity. Is it correct?
 
  • #4
HAF said:
If I understand it correctly then light's speed is not changing and that's against the Galilean relativity. Is it correct?
Yes
 
  • #5
Dale said:
Yes
Thank You so much people. You are amazing!
 
  • #6
It's important to distinguish between Galilean relativity, which underlies Newtonian physics, and Einsteinian relativity, which underlies modern physics. Both systems respect the principle of relativity. Also, both systems have a speed that's the same in all inertial reference frames - in Galilean relativity it's infinite speed and in Einstein's relativity it's a finite speed, the one at which light propagates.

The problem in the latter half of the 19th century was that electromagnetic theory did not appear to respect the principle of relativity. As Orodruin notes, it turned out not to respect Galilean relativity, but Einstein's version wasn't known at the time.

It didn't initially occur to anyone that the problem was with Newton and Galileo. An obvious solution was to propose that there was a preferred frame for electromagnetism, and a plausible way to introduce this is to propose some medium (the ether) and guess that Maxwell's equations are a special case that work in the frame where the ether is at rest. So we started searching for evidence of the ether, hoping to develop evidence that would lead to a more general form of Maxwell's equations.

However, we never found evidence of an ether. But explaining why we hadn't found it so far lead to (what we regarded as) a set of patches to Maxwell's equations. This is why the core maths of special relativity is named after Lorentz. Einstein's initial triumph was to re-derive the Lorentz transforms, starting from just the Principle of Relativity and the assumption that the speed of light is the same in all inertial reference frames, and to show that they could apply to everything (not just electromagnetism) and to explain how we had missed that fact. Nasty run-on sentence left into highlight just how broad this success was.

So the initial problem was that Maxwell's equations didn't respect Galilean relativity. Trying to fix Maxwell didn't work out well, and we ended up fixing Galilean relativity to make Einsteinian relativity instead. Maxwell's equations still don't respect Galilean relativity, but they do respect Einsteinian relativity.
 
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  • #7
Ibix said:
It's important to distinguish between Galilean relativity, which underlies Newtonian physics, and Einsteinian relativity, which underlies modern physics. Both systems respect the principle of relativity. Also, both systems have a speed that's the same in all inertial reference frames - in Galilean relativity it's infinite speed and in Einstein's relativity it's a finite speed, the one at which light propagates.

The problem in the latter half of the 19th century was that electromagnetic theory did not appear to respect the principle of relativity. As Orodruin notes, it turned out not to respect Galilean relativity, but Einstein's version wasn't known at the time.

It didn't initially occur to anyone that the problem was with Newton and Galileo. An obvious solution was to propose that there was a preferred frame for electromagnetism, and a plausible way to introduce this is to propose some medium (the ether) and guess that Maxwell's equations are a special case that work in the frame where the ether is at rest. So we started searching for evidence of the ether, hoping to develop evidence that would lead to a more general form of Maxwell's equations.

However, we never found evidence of an ether. But explaining why we hadn't found it so far lead to (what we regarded as) a set of patches to Maxwell's equations. This is why the core maths of special relativity is named after Lorentz. Einstein's initial triumph was to re-derive the Lorentz transforms, starting from just the Principle of Relativity and the assumption that the speed of light is the same in all inertial reference frames, and to show that they could apply to everything (not just electromagnetism) and to explain how we had missed that fact. Nasty run-on sentence left into highlight just how broad this success was.

So the initial problem was that Maxwell's equations didn't respect Galilean relativity. Trying to fix Maxwell didn't work out well, and we ended up fixing Galilean relativity to make Einsteinian relativity instead. Maxwell's equations still don't respect Galilean relativity, but they do respect Einsteinian relativity.
Thank You for clarifying
 

What is Maxwell's EM theory?

Maxwell's EM theory, also known as Maxwell's equations, is a set of four equations that describe the behavior of electric and magnetic fields. These equations were developed by James Clerk Maxwell in the 19th century and are considered one of the cornerstones of classical electromagnetism.

What is the Principle of Relativity?

The Principle of Relativity, also known as the Theory of Relativity, was first proposed by Albert Einstein in the early 20th century. It states that the laws of physics are the same for all observers in uniform motion and that the speed of light is constant regardless of the observer's frame of reference.

How do Maxwell's EM theory and the Principle of Relativity relate?

Maxwell's EM theory and the Principle of Relativity are closely related as they both deal with the fundamental laws of physics. Maxwell's equations describe the behavior of electric and magnetic fields, while the Principle of Relativity explains the relationship between different observers and their frames of reference.

What is the significance of the relationship between Maxwell's EM theory and the Principle of Relativity?

The relationship between Maxwell's EM theory and the Principle of Relativity is significant because it helped pave the way for the development of Einstein's special theory of relativity. This theory further expanded our understanding of the laws of physics and their relationship to different frames of reference.

Are there any conflicts between Maxwell's EM theory and the Principle of Relativity?

No, there are no conflicts between Maxwell's EM theory and the Principle of Relativity. In fact, the two theories are complementary and have been successfully integrated into our understanding of the fundamental laws of physics. They both play important roles in fields such as electromagnetism, optics, and modern physics.

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