### Time dilation in Wikipedia

 1 Nicolaas Vroom Time dilation in Wikipedia Thursday 6 july 2017 2 dlzc Re :Time dilation in Wikipedia Thursday 6 july 2017 3 Nicolaas Vroom Re :Time dilation in Wikipedia Friday 7 july 2017

Time dilation in Wikipedia 3 posts by 2 authors https://groups.google.com/forum/?fromgroups=#!topic/sci.physics.relativity/3rQydkcG7E0

### 1 Time dilation in Wikipedia

From: Nicolaas Vroom
Datum: Thursday 6 july 2017
1) Time dilation is discussed in the following URL:
https://en.wikipedia.org/wiki/Lorentz_factor In here we can read: "Time dilation: The time (dt') between two ticks as measured in the frame in which the clock is moving, is longer than the time (dt) between these ticks as measured in the rest frame of the clock: dt' = gamma * dt " That maybe true but how are this time differences measured in both the rest frame and the moving frame? I expect in order to do that you need an extra clock? or two?

2) In the url: https://en.wikipedia.org/wiki/Lorentz_transformation In here we can read:
"Time dilation: Suppose there is a clock at rest in F. If a time interval (say a "tick") is measured at the same point so that dx = 0, then the transformations give this tick in F' by dt' = gamma*dt. Conversely, suppose there is a clock at rest in F'. If a tick is measured at the same point so that dx' = 0, then the transformations give this tick in F by dt = gamma*dt'. Either way, the boosted observer measures longer time intervals than the observer in the other frame." Also here how do you do that.
3) In the url https://en.wikipedia.org/wiki/Proper_time the twin "paradox" is discussed in paragraph 2.1 In here we have one observer who stays at home for 10 years and a moving observer (physical two) who travels at a speed away for 2,5 years and back for 2.5 years (using his own clock) with a speed of v = 0,866*C and a speed of v = -0.866*c
Also here the question is how are all these parameters measured if you want to validate gamma.
IMO methode 3 is the best one as a starting point to test "Time dilation", which is also horrible terminology. A better name is to call it: the behaviour of "moving clocks". I expect the outcome will be that if we want to understand the laws of nature we should not use (relatif) "moving clocks"

Nicolaas Vroom. http://users.pandora.be/nicvroom

### 2 Time dilation in Wikipedia

From: dlzc
Datum: Thursday 6 july 2017
Dear Nicolaas Vroom:

On Thursday, July 6, 2017 at 12:59:26 AM UTC-7, Nicolaas Vroom wrote: ...
 > IMO methode 3 is the best one as a starting point to test "Time dilation", which is also horrible terminology. A better name is to call it: the behaviour of "moving clocks". I expect the outcome will be that if we want to understand the laws of nature we should not use (relatif) "moving clocks"

Think about what you just said, in terms of the postulates. If we cannot tell how fast or in which direction we are moving, by just the laws of physics, then we already "understand the laws of nature".

The entire purpose of Relativity, is to correctly infer what a moving / accelerating observer would measure, compared to what we measure.

I expect the outcome will be that you think about what you are saying, before you say it.

David A. Smith

### 3 Time dilation in Wikipedia

From: Nicolaas Vroom
Datum: Friday 7 july 2017
On Thursday, 6 July 2017 16:03:46 UTC+2, dlzc wrote:
 > Dear Nicolaas Vroom: On Thursday, July 6, 2017 at 12:59:26 AM UTC-7, Nicolaas Vroom wrote: ...
 > > IMO methode 3 is the best one as a starting point to test "Time dilation", which is also horrible terminology. A better name is to call it: the behaviour of "moving clocks". I expect the outcome will be that if we want to understand the laws of nature we should not use (relatif) "moving clocks"
 > Think about what you just said, in terms of the postulates. If we cannot tell how fast or in which direction we are moving, by just the laws of physics, then we already "understand the laws of nature".

What I said has nothing to do with the postulates. What I try to say that if you want to understand the laws of nature For example the behaviour of the planets around the sun or the behaviour of the sun through our galaxy, than you should not use moving clocks (relatif to each other) because the behaviour of the individual clocks varies. As such the best strategy is to use only clocks fixed to the coordinate system.

 > The entire purpose of Relativity, is to correctly infer what a moving / accelerating observer would measure, compared to what we measure.

Definitely you should not use accelarating clocks, as indicated, to study the laws of nature. A whole different issue to study the behaviour of moving clocks. What is important to indicate that the behaviour of moving clocks has nothing to do with the concept time.

 > I expect the outcome will be that you think about what you are saying, before you say it.

I have to think about that.

Nicolaas Vroom