Talk:Time dilation

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Former good article nominee Time dilation was a good articles nominee, but did not meet the good article criteria at the time. There are suggestions below for improving the article. Once these issues have been addressed, the article can be renominated. Editors may also seek a reassessment of the decision if they believe there was a mistake.
December 16, 2006 Good article nominee Not listed
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Speed vs. Velocity[edit]

It seems that most of the discussion of velocity is really a discussion of speed. The difference is that velocity is a vector, which has direction. If the discussion were really about velocity, direction should enter the discussion. — Preceding unsigned comment added by (talk) 16:59, 7 February 2013 (UTC)

In some cases in this article (eg; in Time dilation#Time dilation due to relative velocity and Time dilation#Time dilation at constant acceleration), velocity also stands for the (positive of negative) projection —a number— of the vector on a single axis. - DVdm (talk) 17:10, 7 February 2013 (UTC)
I don't know who started it, but speed is all that matters. The East and West-bound jets in the atomic clock experiments make the problem worse. That was done simply to get two different speeds (+ or - Earth's rotation) for checking the equations. A casual reader could get the idea that direction matters. Free of other factors, it does not. I think the use of v came from the derivation of the equation. Frank Layden (talk) 19:56, 19 November 2013 (UTC)

Speed is NOT "all that matters" in a discussion of time for an event. It is necessary to avoid vector mismatch when computing time from displacement and velocity. Using light forward propagation speed for a component of displacement skewed to that propagation produces an incorrect time. Using a proper velocity component of light for an accumulated displacement component produces the correct time. When vectors are matched properly, time is identical calculated by stationary and moving observers of a particular event in which light spans a particular displacement (see Physics Essays, Volume 27(1), 2014,pp 116-125. --Rsauerheber (talk) 19:53, 30 June 2014 (UTC)

"'Space' and 'Length'; 'Time' and 'Duration'" ; and "How Measurement of 'Time' is different from the measurement of 'Length'"[edit]

The terms: 'space' and 'time' need some clarification. What contracts in special-relativity is 'length' of 'physical-objects', not 'space'. What gets dilated in special-relativity is 'duration' of an 'event', not 'time'. 'Space' is there, and 'objects' are in 'space'; so a ruler can measure 'length' of an 'object'. Whereas 'time' is a 'mental-concept'; the 'duration-between-two-tiks-of-a-clock' is defined as a 'duration-of-one-second'; actually there is nothing like 'time'. Thus the so-called 'relativistic-time-dilation' means, 'extension-of-duration-of-an-event' as perceived by 'relativistically-moving-observers'. Such relativistic 'length-contraction' and 'time-dilation' can be alternatively-understood' as described in a recent paper:titled: "Wave-theoretical in-sight into the Relativistic length-contraction and time-dilation-of-super-nova-light-curves", by Hasmukh K. Tank, published in Advanced Studies in Theoretical Physics. Full-text PDF is freely available at: (talk) 10:40, 19 November 2013 (UTC)

What contracts in special-relativity is neither the 'length' of 'physical-objects' nor 'space' but the measuremens thereof. For example if you have two rigid rods of length L separated by a gap of length G in the rest frame of the rods, those distances wll transform to F' and G' in a frame moving with respect to the first when the Lorentz Transforms are applied to the coordinates of the ends of the rods. George Dishman (talk) 12:54, 6 February 2014 (UTC)

Time dilation within other view than scientific view[edit]

I think the information Ibensis placed in the Time dilation article (which I reverted, but is now back in) would be better placed in another article (say, on Islam). This article is about a physical phenomenon. Coldcreation (talk) 14:09, 2 January 2015 (UTC)

Thank you for sharing your reason for reverting. So, in my opinion. My information is not breaking any wikipedia rules and policies. As i said before, the information i gave is still relevant with the article and have proper source. While it's not necessary to make a new individual page to talk about time dilation in islamic view, and its more spesific to place here than in Islam article. And since wikipedia is Free encyclopedia not pure scientific journal and the like, my information is rightful to stay in the article. The scientifc info is in the upper part of article, and relevant little trivial information about Time dilation place in the bottom. it will not bothering anyone. i hope your understanding. ibensis (What’s the Story?) 15:44, 2 January 2015 (UTC)
I think it shouldn't be placed anywhere on Wikipedia, as it is a school book example of original research, based on some source—see wp:NOR. I have removed it from the article. - DVdm (talk) 15:47, 2 January 2015 (UTC)
Apparently user Ibensis has restored the content both here and in article Time. Clearly whether this passage in the Quran is really referring to time dilatiion—as described in this article—is a matter of opinion and interpretation of a wp:primary source. As such this is original research. - DVdm (talk) 16:02, 2 January 2015 (UTC)
I agree. The Quran is an outstanding example of a primary source and Ibensis's use of it here and in Time is clearly in breach of policy - see Wikipedia:Verifiability. NebY (talk) 16:26, 2 January 2015 (UTC)
are you really fair with what you talk about. if my information is an original research, then im afraid you must removed most article in wikipedia. after all its just trivia, it said what it said. dont even need to take a research to know it. how about you googling about this to figure its an original research or its just a simple information base on a writting of notable book. please search: the text and number of verses of my paragraph with google search. its easy ibensis (What’s the Story?) 16:31, 2 January 2015 (UTC)
We are fair with what we talk about in so far as we are talking about Wikipedia's policies - please do read about wp:primary sources and wp:original research. Then, unless you can produce reliable wp:secondary sources, please remove, or—if already removed by others—do not restore the addition in both articles. Thanks. - DVdm (talk) 16:36, 2 January 2015 (UTC)


I cannot believe my eyes, such a simpile theoretical physics lecture about the time dialation effect made not understandable. So sad... Anonamous guy (talk) 03:29, 21 January 2015 (UTC)

There is always the Simple Wikipedia if you need [1]... Tetra quark (don't be shy) 03:43, 21 January 2015 (UTC)

Simple inference of time dilation due to relative velocity[edit]

The diagram showing the moving reference frame in this section needs to have the arrows' direction swapped. The moving plate should have the opposite directional velocity than the photon moving at the speed of light. The photon does not receive any lateral velocity input from the plate, it still only moves up and down, the plate is what is moving relative to the photon. Ex: Plate moving -->, photon moving <-- instead of the current which is: Plate moving -->, photon moving --> Xenocide321 (talk) 15:02, 4 February 2015 (UTC)

Please put new talk page messages at the bottom of talk pages and sign your messages with four tildes (~~~~). Thanks.
The diagram is correct (and backed by 4 sources). This was discussed before—see archives. - DVdm (talk) 15:31, 4 February 2015 (UTC)

i wonder if what just read is accurate or it is my misunderstanding?. "The (time-speeding up) effects of low-gravity would not cancel out these (time-slowing down) effects of velocity unless the ISS orbited much farther from Earth." should this read "unless the ISS orbited much slower" ?Wikimalkindy (talk) 18:59, 15 February 2015 (UTC) i erase my case, my mistake, i was reading the word"farther" as faster !!!Wikimalkindy (talk) 19:02, 15 February 2015 (UTC)