Talk:Time dilation: Difference between revisions

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			== Misleading Animation ==
	== Dilation in parallel movement ==
			The animation where the red clock rotates around the blue clock as illustration for special relativistic effects is misleading, since at least one of the two clocks is not part of an inertial system and thus SRT does not apply. <!-- Template:Unsigned IP --><small class="autosigned">— Preceding ] comment added by ] (]) 14:41, 10 April 2022 (UTC)</small> <!--Autosigned by SineBot-->

			:How do you figure? SRT applies to the red clock; the animation shows the effect on that clock compared to the frame of reference of the blue clock. —''']''' (]) 14:45, 10 April 2022 (UTC)
	I propose including the case of a moving observer traveling parallelly. Since all calculations are ] operations, I would like to invoke ]. Anyway, readers need more mathematical knowledge to understand the orthogonal case. ] (]) 05:05, 31 August 2020 (UTC)
			:: The red clock is rotating around the blue clock so it is not representing an inertial system and so the SRT approach to time dilation does not apply to the red clock. (Well: Of course also the blue clock could be rotating around the red clock, if we take the red clock to be inertial. However, at least one of the systems is not an inertial system.) Of course, in this situation there also is time dilatation, but it is not a special relativistic effect alone. We have general relativistic effects as well, since acceleration is part of the game (or, locally equivalently, gravitation). <!-- Template:Unsigned IP --><small class="autosigned">— Preceding ] comment added by ] (]) 11:30, 11 April 2022 (UTC)</small> <!--Autosigned by SineBot-->
	:We could only add that other case if there is a reliable source. Otherwise it is ], and this is way beyond ]. But the idea of the section is to give a simple inference of time dilation as a consequence of the invariance of light speed, and orthogonal movement w.r.t. to the light signals is the way it is almost always done in the literature. So I don't think we need another way here. - ] (]) 06:35, 31 August 2020 (UTC)
			::: You share a common misconception that SRT does not apply to accelerated systems. It does. Where SRT does '''not''' apply is in the presence of gravitation. See ] ] (]) 11:59, 11 April 2022 (UTC)

			::::Interesting argument. Agreeing to yours. Mine runs as follows: The red clock is accelerated. By the equivalency principle this acceleration is locally equivalent to a gravitational field. This gravitational field produces a time dilatation. This effect is not predicted by SRT. So while the SRT might mathematically be used (as your citation suggests), the SRT formula will produce an incorrect result. I agree that the SRT can be used. I fear it will produce an incorrect prediction in the scenario we are looking at. Which leaves us with an illustration in the article suggesting a theory which will be delivering a result which is different from current state of the art (which should use ART, despite the fact that SRT does produce a consistent result, different from experiment). Interested in your opinion on this. ] (]) 17:25, 11 April 2022 (UTC)
	:# You should undo your {{diff2\|975975775\|\|reversion}} because the edit is independent of this discussion. It is not original research, but a clarification of the described case. It does not reach any conclusion about the parallel case.<p>It is as in {{oldid2\|972193973\|Occurrence\|Lorentz factor}}: "The simplest case is a boost in the x-direction."
	:# Misplaced Pages asserts that time dilation is:<p><math>\Delta t' = \gamma \Delta t</math><p>This insinuates that it is always true, so ] is broken.
	:# Why do you say this is way beyond WP:CALC? Do you know the result? Do you not understand the calculations? ] (]) 14:30, 31 August 2020 (UTC)

	::# I your edit because it is irrelevant in the context of the section.
	::# Without specification of the physical meanings of the variables and the context, that equation is meaningless. This is physics, not mathematics.
	::# Yes, I understand the calculations, but what you have in mind, aren't just routine calculations: again this is about a physical situation with a relevant physical context, and a source is needed to establish (1) correctness of the ''physical reasoning'', and, just as importantly, (2) whether the content is ] to be included in Misplaced Pages to begin with. If no textbook ever mentions it in the context of time dilation inference from light speed invariance, then it has no place in Misplaced Pages—by design. I don't recall having seen in the literature any inference of time dilation from LS-invariance with a light clock and an observer moving non-perdendicularly w.r.t. the clock. - ] (]) 15:35, 31 August 2020 (UTC)

	::::: You say that you understand the calculations. Tell us what is the time dilation in parallel movement and I will be convinced. ] (]) 16:15, 31 August 2020 (UTC)
	:::::: Alas, that is off-topic here on the article talk page per ]; here we cannot discuss the subject, but only the article and proposed changes to it, based on ].
	:::::: I know there are many webpages out there where the time dilation of the "horizontal" light clock is shown as some sort of verification, where the reasoning ''also'' relies on length contraction of the clock, derived from the Lorentz transformation. But the idea ''in this section in this article'' is to infer time dilation from LS invariance (and the Pythagorean theorem) ''only'', in other words, where length contraction is not yet known, let alone the Lorentz transformation. - ] (]) 18:21, 31 August 2020 (UTC)

	{{od\|::::::}} So you do not understand the calculations after all. Someone should publish the research for the general case first. Thank you for your time <!--dilation-->. ] (]) 22:55, 31 August 2020 (UTC)
	: Yes, someone should publish the research for the general case first, generating a ]—that Misplaced Pages does not really want. As soon as that primary source is discussed and cited in the established literature, there will be ] establishing the noteworthyness of the research—which is what Misplaced Pages really needs, by design. So patience is what you probably need here. And some luck. - ] (]) 23:07, 31 August 2020 (UTC)

	:: I still believe the section could be improved now. I would add this sentence to the end:
	::: In this reasoning, {{math\|''L''}} is perpendicular to {{math\|''v''}}; thus, it is not affected by ].
	:: Then I would remove length contraction from "See also". ] (]) 23:10, 1 September 2020 (UTC)
	::: The reasoning does indeed not depend on length contraction, but neither does it depend on relativity of simultaneity, or on temperature or on atmospheric pressure {{smiley}}. But all that is irrelevant in the context of the section. Remember, the section is about inference of a phenomenon (time dilation) from first principles (light speed invariance). Bringing in length contraction here would be ], and even with a source, it would still be a school book example of ]. Unless of course you find a source that —in the context of ''this particular'' reasoning— states that LC is not applicable due to the perpendicularity of the clock. None of the four cited sources mention this. The ''see also'' entry for length contraction is there because length contraction is ''another'' consequence of the postulates. - ] (]) 09:14, 2 September 2020 (UTC)

	:::: I disagree with your argument, but do as you wish. You are negligibly benefiting the not-so-smart reader at the expense of not heavily penalizing the smart one. If you had some people reading that section, you would understand my suggestion. Thanks again. ] (]) 04:50, 3 September 2020 (UTC)

	::::: This {{oldid2\|921461359\|SYNTH is not just any synthesis\|explanation}} of what SYNTH is not may be useful to editors with time travel capabilities. ] (]) 08:30, 4 September 2020 (UTC)

	:::::: Is this good enough 4U? ] (]) 09:35, 5 September 2020 (UTC)
	::::::: I hadn't seen that before and it looks correct, thanks for sharing. It is not widely cited () but it is indeed a nice thought experiment to independently infer both length contraction and time dilation from first principles. It is of course a different thought experiment (with a more complicated physical setup) than the usual standard "vertical" clock. Perhaps we can include a little sourced remark at the end of the subsection. Something along the lines of this: "''In a thought experiment using a square light clock, both time dilation and length contraction can be independenly infered from fist principles.<ref>{{cite journal \|last=Galli \|first=J. Ronald \|last2=Amiri \|first2=Farhang \|date=2012 \|title=The Square Light Clock and Special Relativity \|url=https://pdfs.semanticscholar.org/3252/f3dfa88d035365f4998047e9e808e70fb773.pdf \|journal=AAPT \|publisher=American Association of Physics Teachers \|volume=50 \|issue= \|page=212 \|bibcode= \|doi=10.1119/1.3694069 \|access-date=5 Sep 2020}}</ref>
	{{talkref}}
	::::::: Afaiac, go ahead... - ] (]) 11:01, 5 September 2020 (UTC)

	{{od\|:::::::}} I would also like to include the part that compares a vertical clock to a horizontal one. I will edit the article later. ] (]) 08:40, 6 September 2020 (UTC)
	:I have added the remark: . For the horizontal clock we need a source. And, of course for a comparison with the vertical clock, we need another source. To make sure we don't anything ], let's first discuss before we add anything here. - ] (]) 09:13, 6 September 2020 (UTC)
	:'''Note''', actually, I think that the addition I just made, might be borderline undue—as in hardly covered in the relevant literature—so I undid that (). I think the section is sufficiently complete. Any addition about different types of light clocks would only add needless complication and would surpass the intention of the section. Others, feel free to comment. - ] (]) 09:29, 6 September 2020 (UTC)

	:: You requested a source. I presented you one that supports the comparison explicitly. Are you telling me now that one reliable source is not enough? ] (]) 00:29, 7 September 2020 (UTC)
	::: The only things the source says about the vertical clock, are {{xt\|"A thought experiment that includes a square light clock is similar to the traditional vertical light beam and mirror clock, except it is made up of four mirrors placed at a 45<sup>o</sup> angle at each corner of a square of length L0, shown in Fig 1."}} and {{xt\|"The traditional “vertical light clock” and “horizontally moving train” are combined into a single device where the horizontal length of the square light clock is measured independent of time dilation."}} I.m.o. these are just an introductory statement and a remark, and not really much of a comparison. And again, there are tons of sources for the vertical clock, but just this one (with its few independent cites) for a square clock, and none for the horizontal clock. So I think mentioning it in the context of ''this'' section in ''this'' article is a bit ]. - ] (]) 10:16, 7 September 2020 (UTC)
	::::Perhaps the article would be best placed in the "Further reading" section. Regardless of how the analysis/comparison turns out, because of the ] a horizontal light clock in the same frame and spatial location and with the same period as the vertical light clock must exhibit the same time dilation. A comparison might be interesting as a physics exercise, but the result has to be the same in the end, so I agree that a mention in this article would appear as undue weight. --] (]) 13:39, 7 September 2020 (UTC)

	::::: I do not suggest including any physics exercise, but the result you are trying to describe. It is not undue weight. ] (]) 02:40, 8 September 2020 (UTC)

	:::* I do not want to talk about square clocks. Please read the source, page 212, paragraph {{tq\|1=The assertion that {{math\|1=''T<sub>V</sub> = T<sub>H</sub>''}} follows from the first principle}}. ] (]) 02:40, 8 September 2020 (UTC)
	:::: Yes, ''T<sub>V</sub> = T<sub>H</sub>''. I don't see how that would be helpful or clarify anything in the context of the section. - ] (]) 08:56, 8 September 2020 (UTC)

	::::: I asked you to read the paragraph. I will edit the article in order for you to see the proposal. ] (]) 03:45, 9 September 2020 (UTC)

	:::::: Here is the {{diff2\|977489120\|Simple inference of velocity time dilation\|proposal}}. ] (]) 04:35, 9 September 2020 (UTC)
	::::::: Ok, unless anyone else objects, I have no problem with that. - ] (]) 09:53, 9 September 2020 (UTC)

	{{od\|:::::::}} It is settled then. Thank you. ] (]) 01:05, 11 September 2020 (UTC)

	== Rescue section "Time dilation in popular culture" ==

	This section would be good for the article to be broad in its coverage, but only if there are secondary sources. ] mentions time dilation without references. ], ], and ] do not mention it. ], ], and ] mention it without references. ] has one reference from ].

	Thus, I would add this small section with the source for ''Interstellar''. I would also move here the sentence about fiction from the lead section. ] (]) 08:11, 12 September 2020 (UTC)

	: This other if from '']''. ] (]) 08:34, 12 September 2020 (UTC)

	:: This is recent. It is from ] regarding ''Time Trap''. ] (]) 08:50, 12 September 2020 (UTC)

	::: from '']'' and another from ] regarding ''Interstellar''. ] (]) 09:10, 12 September 2020 (UTC)

	:::: from ] that also mentions ''Planet of the Apes'' and from ] and ] about ]. I think this section is justified. ] (]) 09:30, 12 September 2020 (UTC)

	For the record, this {{diff2\|980713703\|edit}} was no Easter egg; look at the source. ] (]) 23:40, 28 September 2020 (UTC)

	:I have looked at the source. Nothing in it warrants a hidden, piped link of the page number, "42", to ]. I have never seen this done for any other reference. Also, this seems contrary to ] (hence why I called it an "easter egg"). What is the purpose of linking the page number to ]? What in the source warrants that hidden, piped link? --] (]) 00:01, 29 September 2020 (UTC)

	:: "I cannot say what it is"{{diff2\|980713703}} ] (]) 00:30, 29 September 2020 (UTC)

	Regarding this {{diff2\|981205878\|edit}}, I would like to point out that I generally use references from sources already present in Misplaced Pages. ] (]) 22:55, 30 September 2020 (UTC)
	:Not a good idea. It's not because a bad source (a blog) is used ], that it can be used again. Read some thoughts about this in ], so I the edit. As a bad ], blogs are at best just someone's personal, irrelevant opinion. And the replies shouldn't even be looked at. - ] (]) 23:24, 30 September 2020 (UTC)

	:: I disagree: it is a good idea when combined with other reasons. ] (]) 23:40, 30 September 2020 (UTC)

	:::IMO, DVdm is correct. Context matters for sources, especially for blogs and other ] sources. If Regehr were a known expert on modern science fiction literature, WP:SPS might allow it; or if this were an article on ] or ] or on Regehr himself, it might as well. However, I don't see how his blog for this article fits the allowed exceptions of WP:SPS. --] (]) 01:55, 1 October 2020 (UTC)

	:::: <!--joke-->... because science fiction writers know more about physics than computer science professors.<!--/joke--> ] (]) 12:05, 1 October 2020 (UTC)

	I have finished this section. Expansion should focus on new media, like theater plays or paintings, rather than adding more than three examples per medium. ''Interstellar'' and ''Tau Zero'' are exceptions because of their coverage; perhaps someone can find similar coverage for other works. ] (]) 22:15, 9 October 2020 (UTC)
	*] need a secondary source (] · ]) ''']''' 04:48, 23 October 2020 (UTC)

	== Time contraction ==

	Regarding this {{diff2\|982944100\|reversion}}, what is this arXiv excuse? What is wrong with a source from ]? ] (]) 21:00, 11 October 2020 (UTC)

	: Every once in a while, a bad paper slips through the review process. J. H. Field is a respected experimental physicist who, unfortunately, has turned his hand to theoretical work, publishing in arXiv a series of fringe articles. In arXiv:1405.5174, he says that the Hafele-Keating experiment was incorrectly analyzed and that length contraction is false, thus resolving the Ehrenfest paradox. In arXiv:1307.7962, he claims that length contraction is spurious. In arXiv:1210.2270, he claims that relativity of simultaneity is unphysical. In arXiv:0811.3562, he claims that the conventional analysis of the twin paradox is full of holes. Naturally, he has self-published (arXiv:physics/0612041) an "Einstein was wrong" paper. And so on and so forth. He also has a lot of fringe stuff in arXiv on quantum mechanics. ] (]) 22:15, 11 October 2020 (UTC)
	:: ... which is one of the many reasons why ] says that "arXiv is a self-published source, and is generally unreliable..." - ] (]) 08:09, 12 October 2020 (UTC)

			== language ==
	::: I rephrase the question: On what grounds an article from J. H. Field that is published in ''American Journal of Physics'' is deemed as unreliable? ] (]) 11:34, 12 October 2020 (UTC)
	:::: By reason of the fact that a consensus of Misplaced Pages editors consider it so. ] provides guidelines, which are interpreted and enforced by Misplaced Pages editors in a consensus process. You will find not find it possible to overturn this consensus, so I would advise you to just drop the matter. ] (]) 13:41, 12 October 2020 (UTC)

			Can we read by myanmar subject ? ] (]) 04:10, 27 January 2023 (UTC)
	::::: Really? By ], I request that you point me to the discussion which establishes that an article from J. H. Field that is published in ''American Journal of Physics'' is unreliable. ] (]) 14:00, 12 October 2020 (UTC)

			:@] Looking at the links to the article in other languages (at the top of the article page), this article is available in Bangla and Sinhala. Does that help? —''']''' (]) 13:12, 27 January 2023 (UTC)
	:::::: This '''''is''''' the discussion. I consider the article, by a known fringe contributor to arXiv, to be unreliable. DVdm also considers it to be unreliable. I suspect that you have some personal stake in seeing the reverted material going into Misplaced Pages, in which case, ] may bear on this topic. ] (]) 15:07, 12 October 2020 (UTC)
	::::::: Not much to be found on the topic: : mostly off-topic, other ], so definitely ] here. - ] (]) 16:02, 12 October 2020 (UTC)
	:::::::: For the record, I also consider articles by a known fringe contributor (in this case J. H. Field) published at arXiv to be unreliable. ] (]) 17:00, 12 October 2020 (UTC)

			Given the forward nature of this kind of time dilation, I would also as do many people like to see a theoretical description of backwards time dilation since this topic has become an interesting point by travel through wormholes or possibly an Alcubiere drive. This of course remains theory how many times the speed of C should one go to travel back in time using a spaceship equiped with an Alcubiere drive if York time concept is non existant. One would as to obide to the law of conservation of energy need to replicate the ships matter except the fuel many rockets are 70 percent fuel and 30 percent matter unless a closed loop engine is used. But in this case nuclear fuel would be used possibly even fusion if attainable since it is more lightweight than fission materials.
	{{od\|::::::::}} I ask for the last time here: What does arXiv have anything to do with ''American Journal of Physics''? ] (]) 17:15, 12 October 2020 (UTC)
			This of course is strictly theoretical but none the less an aspect that should as theory be added to this time dilation topic, with mention of its theoretic nature. <!-- Template:Unsigned IP --><small class="autosigned">— Preceding ] comment added by ] (]) 11:20, 16 March 2023 (UTC)</small> <!--Autosigned by SineBot-->
	: As I stated before, occasional mistakes happen in the review process, and bad papers '''''do''''' get published in reputable journals. That is one reason why Misplaced Pages also includes recommendations to avoid primary sources whenever possible, but to instead use mainly secondary sources so that primary source material can be put into proper context.
	: We have so far, without any attempt at ] on my part, three editors (including me) who agree that material based on J. H. Fields' work should not be in Misplaced Pages. It will not be allowed in, so give it up. ] (]) 18:47, 12 October 2020 (UTC)

			== Larmor misquoted ==
	:: So you are implying that this source from ''Am. J. Phys.'' is unreliable without any reliable source proving this is the case indeed. I propose a compromise: I will use conditional tense, like "Time contraction would be a similar special relativistic effect", to soften the certainty of the claim. If you disagree and feel we have discussed enough, I will continue to the dispute resolution noticeboard. ] (]) 23:35, 12 October 2020 (UTC)
	::: By itself, the <s>un</s>conditional would stack ] ''on top of'' an ], making the edit even worse. - ] (]) 09:00, 13 October 2020 (UTC)

			The quote starting "individual electrons describe corresponding.." gives the incorrect equation. From the paper the quote should be "and the individual electrons describe corresponding parts of their orbits in times shorter for the latter system in the ratio e^-1/2 or (l — ½v²/c²), while those less advanced in the direction of v are"
	:::: I guess you mean "the conditional would stack". No problem, I will not use conditional. We are not going to reach a compromise. Are we done discussing here? ] (]) 14:15, 13 October 2020 (UTC)
	::::: Indeed, the conditional, yes. Struck the un. - ] (]) 14:56, 13 October 2020 (UTC)

			In the article text the equation is given as √(1—v²/c²) which is the the inverse of the Lorentz and Einstein equation for gamma ] (]) 11:08, 21 April 2023 (UTC)
	'''Note''': anon filed ] without notifying community. - ] (]) 08:59, 15 October 2020 (UTC)

	~~'''Note'''~~: ~~RFC~~ ~~closed:~~ . - ] (]) 21:46, 21 ~~October~~ ~~2020~~ (UTC)		:In the quoted text we have ε = 1/(1−v²/c²), and so, as you can verify, ϵ^(−½) = √(1—v²/c²), which is, as you can also verify, (1 — ½v²/c²) to first order in v²/c². In this article, we have simply left it as √(1—v²/c²), in stead of going to first order. Look at it as a semi-quote. I the double quotes. - ] (]) 13:13, 21 April 2023 (UTC)
	:It has now been brought to ]. ] (]) 09:18, 22 October 2020 (UTC)
	:: The IP editor has been ''extremely'' persistent in the discussion on the Reliable Sources Noticeboard. ] (]) 03:12, 29 October 2020 (UTC)

			== Some suggestions, again .... ==
	* ] --] (]) 19:44, 29 October 2020 (UTC)

			I am 87 now ! Must I await to be 100 years before you will accept my suggestions formulated in 2017 ! 🤔
	== RfC on Time contraction ==

			See https://phymatheco.github.io
	<!-- ] 23:01, 22 April 2021 (UTC) -->{{User:ClueBot III/DoNotArchiveUntil\|1619132474}}
	{{rfc\|sci\|rfcid=59EFC92}}
	How should we solve the ] in ]? ] (]) 22:40, 18 March 2021 (UTC)

			Read it before suppressing it , Non second chance !!! ] (]) 16:31, 3 February 2024 (UTC)
	* As there is no such thing as time contraction, and as this was discussed , let's get rid of that redirect. - ] (]) 23:00, 18 March 2021 (UTC)
	* From the ]
	::''Before using the RfC process to get opinions from outside editors, it's often faster and more effective to thoroughly discuss the matter with any other parties on the related talk page. Editors are normally expected to make a reasonable attempt at resolving their issues before seeking help from others. If you are able to come to a consensus or have your questions answered through discussion with other editors, then there is no need to start an RfC.''
	:I have seen no prior discussion on the fate of the redirect ] and the proper place to discuss that is at ]. Consensus at this page and in related discussions seem to fall against including a mention of the idea in this page. The RFC is beginning to look a bit pointy. --] (]): 09:20, 19 March 2021 (UTC)

			: Still no need to read it, as Misplaced Pages still does not accept ] {{smiley}} - ] (]) 20:02, 3 February 2024 (UTC)
	== "Time contraction" listed at ] ==
			::You cheat ! See Gourgoulhon General Relativity ! ] (]) 22:40, 3 February 2024 (UTC)
	]
	A discussion is taking place to address the redirect ]. The discussion will occur at ] until a consensus is reached, and readers of this page are welcome to contribute to the discussion. <!-- from Template:RFDNote --> ] (]) 23:03, 18 March 2021 (UTC)

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Misleading Animation

The animation where the red clock rotates around the blue clock as illustration for special relativistic effects is misleading, since at least one of the two clocks is not part of an inertial system and thus SRT does not apply. — Preceding unsigned comment added by 217.95.168.158 (talk) 14:41, 10 April 2022 (UTC)

How do you figure? SRT applies to the red clock; the animation shows the effect on that clock compared to the frame of reference of the blue clock. —C.Fred (talk) 14:45, 10 April 2022 (UTC)

The red clock is rotating around the blue clock so it is not representing an inertial system and so the SRT approach to time dilation does not apply to the red clock. (Well: Of course also the blue clock could be rotating around the red clock, if we take the red clock to be inertial. However, at least one of the systems is not an inertial system.) Of course, in this situation there also is time dilatation, but it is not a special relativistic effect alone. We have general relativistic effects as well, since acceleration is part of the game (or, locally equivalently, gravitation). — Preceding unsigned comment added by 87.163.198.2 (talk) 11:30, 11 April 2022 (UTC)

You share a common misconception that SRT does not apply to accelerated systems. It does. Where SRT does not apply is in the presence of gravitation. See Spacetime_diagram#Accelerating_observers Prokaryotic Caspase Homolog (talk) 11:59, 11 April 2022 (UTC)

Interesting argument. Agreeing to yours. Mine runs as follows: The red clock is accelerated. By the equivalency principle this acceleration is locally equivalent to a gravitational field. This gravitational field produces a time dilatation. This effect is not predicted by SRT. So while the SRT might mathematically be used (as your citation suggests), the SRT formula will produce an incorrect result. I agree that the SRT can be used. I fear it will produce an incorrect prediction in the scenario we are looking at. Which leaves us with an illustration in the article suggesting a theory which will be delivering a result which is different from current state of the art (which should use ART, despite the fact that SRT does produce a consistent result, different from experiment). Interested in your opinion on this. 87.163.198.2 (talk) 17:25, 11 April 2022 (UTC)

language

Can we read by myanmar subject ? Waiyanaungphyo (talk) 04:10, 27 January 2023 (UTC)

@Waiyanaungphyo Looking at the links to the article in other languages (at the top of the article page), this article is available in Bangla and Sinhala. Does that help? —C.Fred (talk) 13:12, 27 January 2023 (UTC)

Given the forward nature of this kind of time dilation, I would also as do many people like to see a theoretical description of backwards time dilation since this topic has become an interesting point by travel through wormholes or possibly an Alcubiere drive. This of course remains theory how many times the speed of C should one go to travel back in time using a spaceship equiped with an Alcubiere drive if York time concept is non existant. One would as to obide to the law of conservation of energy need to replicate the ships matter except the fuel many rockets are 70 percent fuel and 30 percent matter unless a closed loop engine is used. But in this case nuclear fuel would be used possibly even fusion if attainable since it is more lightweight than fission materials. This of course is strictly theoretical but none the less an aspect that should as theory be added to this time dilation topic, with mention of its theoretic nature. — Preceding unsigned comment added by 84.24.84.243 (talk) 11:20, 16 March 2023 (UTC)

Larmor misquoted

The quote starting "individual electrons describe corresponding.." gives the incorrect equation. From the paper the quote should be "and the individual electrons describe corresponding parts of their orbits in times shorter for the latter system in the ratio e^-1/2 or (l — ½v²/c²), while those less advanced in the direction of v are"

In the article text the equation is given as √(1—v²/c²) which is the the inverse of the Lorentz and Einstein equation for gamma 2001:8003:146B:CD00:819A:61CD:C43C:35E1 (talk) 11:08, 21 April 2023 (UTC)

In the quoted text we have ε = 1/(1−v²/c²), and so, as you can verify, ϵ^(−½) = √(1—v²/c²), which is, as you can also verify, (1 — ½v²/c²) to first order in v²/c². In this article, we have simply left it as √(1—v²/c²), in stead of going to first order. Look at it as a semi-quote. I removed the double quotes. - DVdm (talk) 13:13, 21 April 2023 (UTC)

Some suggestions, again ....

I am 87 now ! Must I await to be 100 years before you will accept my suggestions formulated in 2017 ! 🤔

See https://phymatheco.github.io

Read it before suppressing it , Non second chance !!! Chessfan (talk) 16:31, 3 February 2024 (UTC)

Still no need to read it, as Misplaced Pages still does not accept wp:original research

- DVdm (talk) 20:02, 3 February 2024 (UTC)

You cheat ! See Gourgoulhon General Relativity ! Chessfan (talk) 22:40, 3 February 2024 (UTC)

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