Talk:Sticky bead argument

message: The article should include an explanation of the difference between spacetime and gravity. In the rod&bead experiment it is unclear why the gravitational waves would affect just the beads along the rod and not the space housing the atoms of the rod itself (and therefore the rod) as well. Gravitational waves are disturbances in spacetime, why affect and move just the beads and not the space housing the atoms of the rod (and the space anywhere the rod may be attached for that matter)? Logic says the entire system would warp evenly with no movement of the beads at all. 86.93.208.34 (talk) 00:51, 12 May 2020 (UTC)
thread_title: Needs clarification

message: The description of the genesis of the "sticky bead" argument suggests that Bondi plagiarized or otherwise appropriated without attribution an argument by Feynman. The meeting's published proceedings show that the "sticky bead" argument was first proposed by Bondi during the question session during Pirani's presentation . (A dashpot is nothing more than a resistive device: e.g., sticky beads on a stick.) This took place at the very beginning of the conference. The proceedings further show that Feynman's suggestion followed it at the very end of the meeting, as a side remark during the closing discussion of the session on the necessity of quantizing gravitation. (In this connection it is worth noting that the conference took place over six days.) I suggest that - absent suitable references showing that Bondi plagiarized or otherwise appropriated without attribution an argument by Feynman - this section be rewritten to more accurately represent the genesis of the argument and eliminate the remarks disparaging Bondi.   — Preceding unsigned comment added by 2601:8C3:857E:61DD:0:0:0:A6 (talk) 18:49, 29 August 2023 (UTC)
replies: text: In this connection it may also worth noting that Feynman apparently  mischaracterized gravitational waves as being longitudinal: i.e.,  the transcript in the conference proceedings “[a] particle situated initially near a long light rod, oriented parallel to the propagation direction, could be made to scrape against the rod by transverse-transverse wave amplitudes.” FinnLS (talk) 23:31, 17 May 2024 (UTC)
thread_title: Description, and Feynman's Argument

message: My initial version was based upon the somewhat confusing account in Kennefick's first cited paper.  Shortly thereafter, I became aware of the very recent Physics Today paper, which I have used to revise my (oversimplified) account.  BTW, I am trying to obtain permission to upload the photograph by Lotte Jacobi of a beaming Albert Einstein sitting with Leon Infeld, apparently taken about 1937, possibly in Einstein's summer home in Long Island.---CH  (talk) 23:04, 6 November 2005 (UTC)
thread_title: Einstein's double reversal

message: Why do we have to read through more than 2/3 of this article before getting to the description of the argument? "Feynman's argument" should be the first subsection. 198.49.180.40 00:38, 6 April 2007 (UTC)
replies: text: Yes, this article seems to be be "an overview of the history of arguments for and against gravitational waves."  Not quite as catchy a title, but probably more accurate.  :)  --Starwed 13:05, 3 September 2007 (UTC)

text: Rod is ultimately attached to massive object, like the earth. Bead is unnattached and is in a kind of freefall. Rod is stationary. Bead is movable. But how do we know that gravitational radiation makes the bead move? It could be some other cause, like thermal or mechanical movement. It is more sensible to look for an observable cause than a cause that has never been detected anywhere. Lestrade (talk) 22:22, 5 February 2009 (UTC)
replies: text: Is the rod rigid? There's no such thing as a rigid body in General Relativity. Miguel (talk) 13:31, 17 October 2011 (UTC)
thread_title:  Description of the argument 

message: I don't understand what is meant by "the hole argument" at the end. —Długosz
:Agreed, either it is a typo for "the whole argument" or it refers to something otherwise unmentioned in the article.  --Starwed 13:04, 3 September 2007 (UTC)
replies: text: Someone must have deleted my mention of Hole argument but this term is well known in the field and that is what I was referring to.  The version I linked to was this version, but I never did write the article I had in mind.  (Note that I would describe the key ideas involved in resolving the hole argument somewhat differently from the current version of the WP article.) ---CH (talk) 19:48, 7 July 2008 (UTC)
thread_title:  "Hole" argument? 

message: The article gives as an example of a system with a time-varying quadrupole moment a bar "rotating about an axis orthogonal to the symmetry axis of the bar".
To me a bar is a rectangular solid with three different edge-lengths.  Such a shape has not one but three axes of symmetry -- each orthogonal to the other two.  (The edge-lengths of a bar tend to be in roughly certain proportions, but this is not relevant here.)
So the phrase "the symmetry axis of the bar" is unclear, since "the" implies there is only one.  I cannot fix this, since I don't know what is meant.  But perhaps a knowledgeable person can express this clearly.Daqu (talk) 04:28, 1 March 2009 (UTC)
thread_title:  Axis orthogonal to "the" symmetry axis of a bar ??? 

message: Einstein's position regarding gravitational waves is more subtle than people give him credit for. He still believed the waves would impart energy and momentum, he just believed that the nonlinearities would make this energy be carried in little points, like gravitons, and that the gravitons would add up to the total energy in the wave.
This is true to some extent, because gravitational waves can collapse to black holes. These black holes can then carry energy and momentum. But the gravitational waves themselves are locally stable, contrary to the Einstein Rosen paper. This was a bit of wishful thinking on Einstein's part.Likebox (talk) 15:42, 1 July 2009 (UTC)
replies: text: Also, in point of fact, the first person to claim that gravitational waves were "ripples in coordinates" and carried no energy and momentum is Eddington. Einstein did not agree then, and never agreed later, with the point of view that quadropole waves would carry no energy. He just wanted the nonlinearities to explain quantum behavior, as I said before.Likebox (talk) 15:44, 1 July 2009 (UTC)
thread_title:  Einstein Rosen collapse 

message: The main page has a header "This article includes a list of references, but its sources remain unclear ..". In searching for a related term, I came across this book by Fredrick Kennard via Google: Thought Experiments. The majority of the article seems to have been copied verbatim from the book but I don't see any attribution, however, perhaps the book copied from Wikipedia.
George Dishman (talk) 09:44, 10 May 2016 (UTC)
thread_title:  Possible "plagiarism" 

message: The text says:
"The thought experiment was first described by Feynman (under the pseudonym "Mr. Smith") in 1957, at a conference at Chapel Hill, North Carolina,[3]"
I've read the source, there's no mention of that pseudonym anywhere. In fact there is a transcript in source [3] (pages 252-260ish) where Feynman mentions the experiment in conversation with others and there is a section at the end of the report giving the argument in detail. It's a fanciful story and it might be true but the source is not [3]. Mef51 (talk) 20:06, 27 October 2017 (UTC)
replies: text: thanks for raising the argument, it's been a while that it has been in doubt, I just took the opportunity to remove it.--ReyHahn (talk) 19:57, 29 August 2023 (UTC)
thread_title:  Feynman's "Mr Smith" Pseudonym