h***@luukku.com

2018-05-08 07:51:12 UTC

General Relativity and Electromagnetism

I refer here recent discussion in sci.physics.research about the subject.

I put one essential copy from the reference below:

“ General relativity is the only fundamentally geometric theory in physics and has stood apart from other theories since its inception.

Its geometric nature is intimately connected with the principle of equivalence and the independence of the trajectory of a test body on the properties of the body such as its mass.

There is no analog of the principle of equivalence in electromagnetism; the motion of a charged test body in an electromagnetic field depends directly on its charge and mass.

The lack of such a principle has hindered the development of a true geometric theory of electromagnetism.

Many attempts at a classical unified theory of gravitation and electromagnetism were made by Einstein, H. Weyl, and others, but the results were not very convincing.

These attempts seem less interesting since the discovery of other forces in nature besides gravitation and electromagnetism.

It would be desirable ultimately to unify the strong and weak nuclear forces, electromagnetism, and gravity, and such a grand unification would necessarily involve quantum theory.

Although there is no convincing classical unified field theory, the Maxwell equations of electromagnetism, when expressed in covariant form, are completely consistent with the ideas and equations of general relativity, and no geometric interpretation of the electromagnetic field is logically necessary.

In this view the electromagnetic field operates conventionally in the curved space described by the gravitational field equations.

In turn, the electromagnetic field contains energy and is thus the source of some of the curvature of the space.

Much work has gone into the elucidation of the properties of the coupled Einstein-Maxwell equations in vacuum, sometimes referred to as already-unified field theory, and interesting formal results and interpretations have emerged. ”

Reference:

Parker, S. P. (Editor in Chief), 1983.

McGraw-Hill Encyclopedia of Physics.

McGraw-Hill Inc, Printed in the U.S.A.

1343 pages, pp. 971-972, (copy from the reference).

Best Regards,

Hannu Poropudas

I refer here recent discussion in sci.physics.research about the subject.

I put one essential copy from the reference below:

“ General relativity is the only fundamentally geometric theory in physics and has stood apart from other theories since its inception.

Its geometric nature is intimately connected with the principle of equivalence and the independence of the trajectory of a test body on the properties of the body such as its mass.

There is no analog of the principle of equivalence in electromagnetism; the motion of a charged test body in an electromagnetic field depends directly on its charge and mass.

The lack of such a principle has hindered the development of a true geometric theory of electromagnetism.

Many attempts at a classical unified theory of gravitation and electromagnetism were made by Einstein, H. Weyl, and others, but the results were not very convincing.

These attempts seem less interesting since the discovery of other forces in nature besides gravitation and electromagnetism.

It would be desirable ultimately to unify the strong and weak nuclear forces, electromagnetism, and gravity, and such a grand unification would necessarily involve quantum theory.

Although there is no convincing classical unified field theory, the Maxwell equations of electromagnetism, when expressed in covariant form, are completely consistent with the ideas and equations of general relativity, and no geometric interpretation of the electromagnetic field is logically necessary.

In this view the electromagnetic field operates conventionally in the curved space described by the gravitational field equations.

In turn, the electromagnetic field contains energy and is thus the source of some of the curvature of the space.

Much work has gone into the elucidation of the properties of the coupled Einstein-Maxwell equations in vacuum, sometimes referred to as already-unified field theory, and interesting formal results and interpretations have emerged. ”

Reference:

Parker, S. P. (Editor in Chief), 1983.

McGraw-Hill Encyclopedia of Physics.

McGraw-Hill Inc, Printed in the U.S.A.

1343 pages, pp. 971-972, (copy from the reference).

Best Regards,

Hannu Poropudas