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Old 19th February 2013, 01:52 PM   #955
Farsight
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Join Date: Mar 2008
Posts: 2,640
Originally Posted by W.D.Clinger
Farsight: I am fully aware that decompositions of the electromagnetic fields into the E and B fields are relativistic, just as decompositions of spacetime into space and time dimensions are relativistic.
Electromagnetic fields Clinger? It's the electromagnetic field. And see above, like Minkowski said, E and B denote linear and rotational force. They aren't actually fields, because like Jackson said, one should properly speak of the electromagnetic field Fuv rather than E or B separately. And the electromagnetic field isn't like spacetime. You can move through space where an electromagnetic field is, you can't move through spacetime. It's a totally different animal. It's a mathematical space in which there is no motion because the time dimension is included. The Earth isn't surrounded by spacetime you know. It's surrounded by space. Yes we talk of curved spacetime, but things don't move through it.

Originally Posted by W.D.Clinger
In other contexts, you have claimed that gravitational fields are real, even though gravitational fields are observer-dependent.
They are real Clinger. Things fall down. An observer in a falling lift might beg to differ with me, but when he hits the ground he will be promptly disabused of that notion.

Originally Posted by W.D.Clinger
(That's Einstein's equivalence principle, BTW, which you have taken such great pains to deny.)
I haven't denied it at all. I've pointed out its limitation wherein a true gravitational field is only exactly equivalent to a pseudo-gravitational field resulting from acceleration in a region of zero extent. It's a principle, not something that claims you can create a gravitational field in space by moving through it in some particular way.

Originally Posted by W.D.Clinger
The E and B fields are observer-dependent also, but they're just as real as gravitational fields.
No they aren't. That's why Einstein said "Of course it would be a great advance if we could succeed in comprehending the gravitational field and the electromagnetic field together as one unified conformation".

Originally Posted by W.D.Clinger
You understand neither electromagnetism nor relativity. If you did understand those things, you'd know what a field is, and you'd know that E and B are fields...trivially...by the very definition of the word field.
No Clinger, I understand it. You don't. And you are resisting my efforts to tell you that Maxwell unififed electricity and magnetism a hundred and fifty years ago. Into the electromagnetic field.

Originally Posted by W.D.Clinger
I provided that link in my post above. You must not have read the Wikipedia article on fields in physics, because you're still making the same absurd claim.
Read your own link. Defining the field as "numbers in space" shouldn't detract from the idea that it has physical reality. The field creates a "condition in space". Like I said to edd, the field is a condition of space.
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