User talk:Cleonis/sandbox/Equivalence Principle

What I think belongs in the article
First: The Principle of Equivalence asserts equivalence between two situations that you would not expect to be equivalent. Those two situations: standing-on-the-surface-of-a-planet and moving-in-gravitationfree-space-being-accelerated should both be mentioned explicitly.

In his article Einstein used the technical term "accelerated frame of reference". First I substitute that with 'a spaceship in gravitation-free space that is being accelerated by a force'. In the next section I substitute Einstein's term with the thinking tools of Gravitation by Misner, Thorne and Wheeler: a latticework of measuring rods and clocks that is either moving inertially, or being accelerated.

I expect the reader of the article on the Principle of Equivalence to be reasonably familiar with special relativity. Principle of Equivalence is general relativity stuff, so special relativity is required prior knowledge.

I go straight for the conjugation with special relativity, since without that conjugation, the Principle of Equivalence is barren and meaningless. --Cleon Teunissen | Talk 11:33, 11 Apr 2005 (UTC)

This does not work
Cleon -

This really does not work. The weak EP is based on the equivalence of being accelerated in both a gravitational field and in an accelerating spaceship. In the latter case, the is no curvature to account for its internal "gravitation".

The WEP is a very simple concept. Please don't mess it up.

I kindly suggest (and I do mean kindly) that you not worry about this page. You are trying and you are learning, but you still have a ways to go before you will really have an understanding of GR.

--EMS 17:10, 11 Apr 2005 (UTC)

The weak EP is based on the equivalence of being accelerated in both a gravitational field and in an accelerating spaceship. In the latter case, the is no curvature to account for its internal "gravitation" --EMS 17:10, 11 Apr 2005 (UTC)


 * It is unclear what your objection involving 'its internal "gravitation"' is about.
 * When a space-ship is being accelerated by thrusters, then there is no need for postulating such a thing as 'an internal "gravitation".  When a space-ship is being accelerated then everything happening inside in a different way from how it would happen in free-fall can be accounted for by the fact that the ship and its contents are being accelerated with respect to the local inertial frame.
 * That is, in my judgement, the consistent way to present these matters.


 * I get the impression that you ascribe assumptions to me that in fact I do not make. I get the impression that what I write appears complicated to you because there are presuppositions in your thinking that are not present in mine.


 * If your comment would have identified an inconsistency in what I have written you would have supported your credibility. But as far as I can tell your comment comes from superficial reading.


 * What I have written is self-consistent and consistent with observations. I will rely on my own judgement in these matters. Please confirm whether you've read this reply --Cleon Teunissen | Talk 22:01, 11 Apr 2005 (UTC)

Getting sandbox articles out of the categories
Cleon -

Our sandbox articles have become listed in thier respective categories. I have fixed mine in two ways:


 * 1) Commenting out the categoty:... lines, or
 * 2) Redirecting the page to the active article

Redirecting is done with a single line that reads


 * 1) REDIRECT Equivalence Principle

as the text of this article.

I have taken the liberty of commenting out the category lines. I advise doing the redirect, but that is your perogative IMO.

--EMS 04:13, 3 May 2005 (UTC)