Talk:Supplee's paradox

Pardon my density (pun intended), but I don't understand what "... the geodesic in the far-field limit is consistent with the object sinking" means in a practical observable sense. If I were to actually watch a bullet passing through the fluid, would I see it rise or fall? Corvus 01:51, 11 Apr 2005 (UTC)


 * Hi Corvus.


 * I'm afraid I didn't understand the paragraph either. I've removed the paragraph from the page and pasted it here (below).  I've done done my best to explain the essense of Supplee and Matsas's papers in the article itself.


 * Robinh 11:58, 11 Apr 2005 (UTC)


 * The full resolution of this paradox was offered by George Matsas of the State University of São Paulo in Brazil. It involves taking into account the general relativistic effects of a fluid with a non-zero energy-momentum tensor that necessarily affects the Riemannian curvature of spacetime. While from the perspective of the bullet, the buoyant force is exerting an upward acceleration on the bullet, due to the pecularities of the spacetime metric the geodesic in the far-field limit is consistent with the object sinking. This is a similar effect to the classic equivalence principle thought experiment that showed there was no difference between an accelerating reference frame and a reference frame subject to a metric that is not Minkowski. At a great enough speed, relativistic effects will ultimately cause the object to pass through an event horizon.


 * (apparently an unsigned comment by Robinh; see 11:58, 11 Apr 2005 (UTC) edit) 


 * Nobody told me that they couldn't understand my language, but the "far-field limit" implies that when you actually look at the bullet passing through the fluid (assuming you aren't close to that relativistic danger) you would see the bullet behave as one would classically expect. In other words, in some ways, the bullet would be sinking into a black hole created by its own stress energy tensor. It might be appropriate to include this layman's answer in the article itself. Joshuaschroeder 06:42, 13 July 2005 (UTC)


 * (regarding the attribution of a comment to )


 * Nope, not me. The only paragraph on this page that is mine is the first one.  Best wishes, Robinh 07:45, 5 May 2006 (UTC)


 * In that case,, how do you explain this diff? ---CH 18:01, 1 July 2006 (UTC)


 * Hi Hillman.  The diff you point to included a paragraph that I wrote, and a paragraph that I cut from the article and pasted into the discussion page after my signature.  At least, I seem to remember that that was my intention and this is consistent with the diff.  I guess this wasn't very clear from the edit, and re-reading our earlier discussion my disavowals made the situation more confusing.   Sorry about that.  Best wishes, Robinh 21:40, 1 July 2006 (UTC)

Students beware
I extensively rewrote the early May 2005 version of this article and briefly monitored it for bad edits, but I am leaving the WP and am now abandoning this article to its fate.

Just wanted to provide notice that I am only responsible (in part) for the last version I edited; see User:Hillman/Archive. I emphatically do not vouch for anything you might see in more recent versions, although I hope for the best. "Paradoxes" tend to controversial topics which attract the attention of many anti-relativity cranks. For example, I believe that recent versions of related articles Ehrenfest paradox and Bell's spaceship paradox are far less accurate and far more misleading than my earlier versions. Thus, I'd advise caution in evaluating anything you read at WP on this or other topics. Similarly for websites found by following links from this article, which may be cranky. Any of these sources may attempt to describe fringe science or pseudoscience as belonging to the canon of well-established mainstream scientific belief, which would be very misleading. More generally, strong comments like "the full resolution was provided" above may be overstated and should not be accepted without careful checking--- if one has the mathematical ability and physical background. For other readers, I can offer no advice, since this interesting topic is probably too recent and obscure for Brittanica or other peer reviewed encyclopedias.

One of the most valuable services a general encyclopedia can offer to general readers is that a good encyclopedia is very far from being merely a disorganized and unevaluated collection of claims and other information/misinformation/disinformation. Rather, the editors have sorted the wheat from the chaff and have carefully and professional checked each other's work to remove bias and inaccuracy. According to the philosophy of wikis, the same thing happens here, but my experience in my year at WP suggests that this is gravely misleading. For one thing, in highly technical subjects, only editors with strong technical background and mathematical ability are likely to be able to assess competing claims accurately and fairly.

Good luck to all students in your search for information, regardless!---CH 18:01, 1 July 2006 (UTC)

Vieira agrees?
The section on the resolution of the paradox says that Vieira's results agree with previous results (i.e. the submarine sinks); however, it seems that the actual cited paper repeatedly argues that the submarine is able to maintain neutral buoyancy. Specifically, I think the gravitational force might be the same as previous results but the net force is not. I don't have the physics background to make sense of the equations so I don't feel confident enough to change the article, but I hope someone more knowledgeable can take a look... .froth. (talk) 01:50, 10 April 2021 (UTC)