Relation between electromagnetism and relativity

[entropy1]

Is there a formalism that relates the properties of energy (electromagnetism) to the properties of spacetime (relativity)?

 

[Orodruin]

Can you be more specific? Your question is very vague.

Also, why do you put an equal sign between electromagnetism and energy?

 

[entropy1]

Can you be more specific? Your question is very vague.

Also, why do you put an equal sign between electromagnetism and energy?

As far as I understand, a link between quantum mechanics and relativity is not yet established? I was wondering if that implied there is not yet a link establised between electromagnetism and relativity. I was wondering because the theory of relativity incorporates light, and so photons, which are quanta.

 

[Herman Trivilino]

I was wondering if that implied there is not yet a link establised between electromagnetism and relativity.

Special relativity is a theory about the relationship between electricity and magnetism.

 

[entropy1]

Special relativity is a theory about the relationship between electricity and magnetism.

Can mass also be viewed in terms of electricity and magnetism?

 

[Orodruin]

Special relativity is a theory about the relationship between electricity and magnetism.

More precisely, Maxwell's theory of electromagnetism, which is invariant under Lorentz transformations and one of the pillars Einstein built his research on, is the theory of electricity and magnetism. Naturally, relativity therefore incorporates it.

Can mass also be viewed in terms of electricity and magnetism?

Again it is unclear what you are intending with this question and why you think there should be a connection.

As far as I understand, a link between quantum mechanics and relativity is not yet established?

Quantum theory works perfectly well with special relativity. The problem is finding a quantum theory of gravitation.

I was wondering because the theory of relativity incorporates light, and so photons, which are quanta.

This is a misconception. Relativity on its own does not incorporate photons. It is a classical theory where electromagnetism are described by classical fields. Now, you can quantise those fields and end up with quantum field theory, where you will have your photons. But make no mistake, photons are not small balls or anything like any object you have encountered. In fact, they are among the most complicated objects which we have described using advanced mathematics.

 

[entropy1]

Again it is unclear what you are intending with this question and why you think there should be a connection.

Actually, that seems an answer to my question, if you mean by that that there is no connection.

Quantum theory works perfectly well with special relativity. The problem is finding a quantum theory of gravitation.

To get this clear: does that mean that acceleration does go together with with QT, but gravitation does not? Is there a fundamental difference between the two? If so, what is it?

This is a misconception. Relativity on its own does not incorporate photons. It is a classical theory where electromagnetism are described by classical fields. Now, you can quantise those fields and end up with quantum field theory, where you will have your photons. But make no mistake, photons are not small balls or anything like any object you have encountered. In fact, they are among the most complicated objects which we have described using advanced mathematics.

Yes, I am aware that photons are more complex objects than little balls of some kind. Thanks for your reply!

 

[Herman Trivilino]

As far as I understand, a link between quantum mechanics and relativity is not yet established?

That's not true. Do a search for "quantum electrodynamics" or "quantum field theory".

 

[entropy1]

Wikipedia:

There is currently no complete quantum theory of the remaining fundamental force, gravity.

Wikipedia:

In particle physics, quantum electrodynamics (QED) is the relativisticquantum field theory of electrodynamics. In essence, it describes how light and matter interact and is the first theory where full agreement between quantum mechanics and special relativity is achieved.

What is the property of gravity that is distinct from relativity? I thought gravity was part of relativity, however, from these Wikepedia quotes I understand that unifying relativity with QM does not imply that gravity is part of QM?

 

[Orodruin]

What is the property of gravity that is distinct from relativity? I thought gravity was part of relativity, however, from these Wikepedia quotes I understand that unifying relativity with QM does not imply that gravity is part of QM?

Gravity is described by the general theory of relativity. Quantum field theory is mostly done in Minkowski space, which is the domain of special relativity. You can also do similar things in curved space-times, but the real problem arises when you attempt to quantise gravity itself.

 

[entropy1]

but the real problem arises when you attempt to quantise gravity itself.

How about the Higgs Boson? I thought that was the quantum of gravity?

Other question: are acceleration and gravity synonymous?

 

[ZapperZ]

Can mass also be viewed in terms of electricity and magnetism?

How about the Higgs Boson? I thought that was the quantum of gravity?

Other question: are acceleration and gravity synonymous?

Have you ever noticed how much you jumped around onto various other topics in this thread?

You had a serious flaw in your understanding about electromagnetism and relativity. Various posters, especially orodruin, was trying to correct that. Yet, before you even understand, or even acknowledge if you have clearly understood this, you JUMPED to other things such as "mass and E&M", and now, the Higgs!

Are you just simply sampling the candy in a candy store, or do you actually intend to make a purchase?

And, for your information, the English translation of Einstein's 1905 paper on Special Relativity is "ON THE ELECTRODYNAMICS OF MOVING BODIES".

So, has the question in the first post been answered?

Zz.

 

[entropy1]

@ZapperZ

I am just asking the questions of which I'd like to know the answers... They don't have to be detailed! This is a very basic thread! Contrary to what might appear so, I do understand the anwers given!

I was not entirely convinced of the strangeness of my questions, although I was very well aware that I might be pushing the patience of forum participants (like you). The question about the Higgs Boson is a little odd, I agree. I just didn't want to make a lot of threads for all my questions, for it is easier to place them directly in the context of my interests as expressed in this thread...

(BTW, these two questions were intended to be my last ones...)

So, if you would bear with me,

1. Is the Higgs Boson the quantum of gravity or not?
2. Are acceleration and gravity always equivalent, and if not, in which context not?

Many thanks!

 

[jtbell]

• Is the Higgs Boson the quantum of gravity or not?

Not.

 

[Nugatory]

Are acceleration and gravity always equivalent, and if not, in which context not?

You are probably thinking of Einstein's famous "equivalence principle" - we have a bunch of threads discussing it. The equivalence principle says that locally (that is, if you only make measurements within a sufficiently small volume of space) the effects of moving with constant acceleration cannot be distinguished from the effects of being stationary in a constant gravitational field.

It does not say that gravity and acceleration are the same - "equivalent" does not mean "is the same thing" - and it does say that the equivalence principle only applies locally.

If you have more questions on this topic, start a new thread but only after you've worked through more of the material that's already out there.

 

[entropy1]

I am not asking new questions, I just want to recapitalize what I've understood in this thread, also to verify if I have: (concluding)

1. Pillars of special relativity are Maxwell's equations, which are invariant under the Lorentz transformations.
2. Relativity does not deal with photons, it deals with the classical notion of electromagnetism. Quantum field theory deals with quantized electromagnetic fields (and photons).
3. Quantum theory is perfectly compatible with special relativity, for both are done in Minkowski space. When general relativity applies, it is not, because QM does not deal with gravity, for there is not yet found a way to compatibly quantize gravity.

Thanks!

 

[ZapperZ]

Quantum theory is perfectly compatible with special relativity, for both are done in Minkowski space. When general relativity applies, it is not, because QM does not deal with gravity, for there is not yet found a way to compatibly quantize gravity.
Thanks!

This is not entirely true. The neutron drop experiment has clearly shown that gravitational potential DOES produced quantized effects. So QM does deal with gravity!

What is not known is if there is such a thing as a quantum field theory equivalent for gravity.

Zz.