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To: MonroeDNA
See my post, #124. Comments?

Don't congratulate yourself too much. It's called the tidal force, and scientists and sailors are aware of it.

Einstein's example was for a uniform (i.e. divergence-free) gravitational field. In principle, you can create a uniform field by constructing a large, flat, massive sheet; near the center of the sheet, the field will be uniform. Or, you can achieve an arbitrary uniformity it by examining a sufficiently small volume of space.

The point of the equivalence principle is not that it isn't possible in practice to tell whether you're on the surface of a planet, but that accelerations and gravitational fields are physically the same phenomenon. That's a pretty radical notion.

Ice is cold and hard while steam is hot and gasseous, but that doesn't alter the fact that they are fundamentally the same stuff.

142 posted on 01/08/2003 6:48:46 PM PST by Physicist
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To: Physicist
Hey, if I sounded like I was congratulating myself, I sure didn't mean it to come accross that way. I just asked a question that has been buging me for a long, long time.

My physics books all say that the two were indistinguishable, and gave the elevator example. It always bugged my profs to no end when I pointed out that they are always distinguishable. Frowns, bad grades, "troublemaker," always followed.

I'm so scarred!!!! LOL!

Yes, of course a "uniform gravitaional field" would be equivelent. But there ain't no such thing, unless someone can give me an example (then I'll go back to the class and shut up). Never has been, never will be.

The elevator thing taught to all budding physicists should have a disclaimer:

Caution: What you are about to hear is false, even reduced to a simplification."

Or am I wrong?

144 posted on 01/08/2003 7:18:09 PM PST by MonroeDNA
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