[Physics] Clocks in relativity

[carmam at tiscali.co.uk]

Thomas, >He doesn't say that. He says that, from the point of view >(i.e. in the reference frame) of observer A, a clock moving 
>with respect to observer A runs slow. I refer you to Einstein's "Relativity The Special And The General Theory". In chapter XII last paragraph (on page 37 in my edition). "As a consequence of its motion, the clock goes more slowly than when at rest." I think that "moving clocks run slow" is a fair summary of that. Don't you?
We can dispense with the qualification "with reference to frame ??" can we not, as it it is well understood by anyone on this forum.
>Depends what you mean by "illusory". This behavior is a brute fact.By using the phrase "this behaviour is a brute fact" do you mean it is physically real?
Einstein himself said (and I am not going to look it up to reference it) "It does not matter what type of clock is used."The point I was making is that a light based clock (cesium / atomic) is not a supremely accurate clock, it is subject to errors, just the same as the pendulum clock. To be sure, the errors are much smaller, and in the opposite sense, but they are there.>Well, obviously. But, in the context of a changing 
>gravitational field (changing acceleration), a pendulum 
>clock is a very poor clock. This remark is so obvious as to 
>be a stupid one.Remarks like this are not helpful.

Saying that the meridian passes the fixed star is bantering semantics.
>And you are wrong. If, for example, you are on the surface 
>of the Earth (thus in a gravitational field), and then the 
>Moon gently coalesces with the Earth (thus increasing the 
>gravitational field that you are in), you will find that 
>the rate of this "meridional clock" changes.The rate of the meridian clock changes by the same amount for the person at the top of the mountain and the person at thebottom, so is unnoticeable to either and they are still in the same time frame. Contrast this with "for the person at the top of the mountain clocks run slower with respect to the person at the base." Also we are here conducting a thought experiment, so we can find a planet without a moon, or simply assume that the moon does not exist.
Tom.



-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://mail.tuks.nl/pipermail/physics/attachments/20161114/09f1253c/attachment.html>