|WikiProject Physics / Relativity||(Rated C-class, High-importance)|
|WikiProject Time||(Rated Start-class)|
"Path integral" vs. "line integral"
"Joke" - I decided to change "line integral" back to "path integral" primarily becuase your change left the article inconsistent both internally and with Wikipedia itself. Internally, there are several references to the path integral in this article, but you only changed one. Also, in Wikipedia, the title of the article is "path integral", not "line integral" (although it does acknowledge line integral as being synonomous with path integral).
If you feel strongly enough on this matter you may change the wording again. All that I ask is that this time you change all occurances of the term "path integral" instead of just one.
- Oh, I didn't notice that it was in multiple places in the article. It's not a big deal, it's just that physicists call functional integrals path integrals. --Joke137 21:06, 1 Jun 2005 (UTC)
- I am aware of Feynman diagrams but not of the intergration being called a "path integral" also. So I now see what my usage is jarring to you. As I wrote above, my big complaint is the loss of consistency instead of the change of terminology. I do not revert edits without a good reason to do so, and would not have reverted yours if the change had been done throughout the article. --EMS | Talk 22:11, 1 Jun 2005 (UTC)
Minor typo in equation?
The last equation seems to be missing a 'dt' at the end; could someone who knows how to edit the equations fix it? Thanks! Fasrad 13:57, 16 October 2006 (UTC)
I've rewritten the verbal definition in the introduction to stress how proper time differs from coordinate time. I've also brought the mathematical definition for SR ahead of the GR definition. Most readers of this article are likely to be learning SR and won't be familiar with GR, index notation, summation conventions and metric tensors.
Your definition of proper time Is meaningless
In the special relativity section you define proper time as tau a function of t called coordinate time. Going to the definition of coordinate time it tells me that coordinate time is proper time in special relativity. Your definition is therefore wrong, confusing and just plain stupid. Wikipedia is again demonstrated to have poor editors who dont know what they are doing.18.104.22.168 (talk) 13:31, 28 March 2008 (UTC)
- The definition of coordinate time does not say "coordinate time is proper time". It says coordinate time (relative to an inertial observer) is the proper time measured by a clock
- (a) that is at the same location as the event,
- (b) that is stationary relative to the observer and
- (c) that has been synchronised to the observer's clock using the Einstein synchronisation convention.
- All three conditions (a) (b) and (c) are necessary: in situations where any of them is false, coordinate time is not the same as proper time.
- When (a) (b) and (c) are all true then, in the mathematical definition of proper time v(t) = 0 (gamma = 1), so tau = t.
- I can assure you the definition given is correct. I have added some extra words of clarification. If you still think it is confusing, can you think of a better way of phrasing it so it isn't confusing? Or can you put your finger on the confusing part? --Dr Greg (talk) 17:18, 1 April 2008 (UTC)
The definition of proper time as tau, indicates that it is less than the coordinate time t. Therefore it indicates that the moving clock tau time is running fast, since the time intervals on this clock are shorter than the time intervals on the rest clock t. This is not time dilation, so either the theory is wrong, or your presentation is wrong. Please fix this mistake.22.214.171.124 (talk) 13:45, 28 March 2008 (UTC)
- If tau is less than t, the tau clock is running slow relative to the t clock. If the clocks are synced at 12 o'clock, then when t reads 2 o'clock, tau might read 1 o'clock, for example (1 < 2). --Dr Greg (talk) 17:18, 1 April 2008 (UTC)
Time corrected by gamma
Would it be accurate to say that proper time is time over gamma?
- In the special case of an inertial observer measuring an inertial object, yes, the proper time of the object equals the coordinate time of the observer divided by the Lorentz factor γ. This follows from the very first equation in the "In special relativity" subsection of the "Mathematical formalism" section. But it wouldn't be true in other circumstances.
- By the way, new sections go at the bottom of the page, not the top. -- 19:30, 22 August 2009 (UTC)