On 25/03/11 14:04, PD wrote:
On Mar 25, 7:27 am, wrote:
On 24/03/11 22:34, PD wrote:









On Mar 24, 4:40 pm, wrote:
On 24/03/11 13:47, PD wrote:

On Mar 24, 7:40 am, wrote:
On 23/03/11 13:50, PD wrote:

On Mar 23, 5:39 am, wrote:
On 22/03/11 18:21, PD wrote:
I think Einstein confused himself thinking that clocks measure
time.

Yes, indeed. Time is what clocks measure.

You cannot have your cake and eat it either time is the reciprocal
of frequency or it is what a clock measures.

Time is not the reciprocal of frequency. Time is benchmarked by a
locally stationary reproducible process. See the NIST standards.

You are ducking the issue:

a/The frequency of a transverse moving clock is reduced.

Yes.

Why do you accept this statement yet query the one below?
Clearly in the context it is moving relative to you and you are
measuring it in your FoR

I shouldn't have, in retrospect. The frequency of the moving clock is
reduced relative to the frequency of ticks on a clock stationary in
this frame.

There is no reduction in any intrinsic frequency in the moving clock's
frame.




b/The time interval between ticks is increased (dilated means increased)

The time interval as measured by a clock at *rest* in this frame is
increased between the ticks of the clock that is moving in this frame,
yes.

I am clearly talking about the same clock as in a/

Then the statement makes no sense. The time interval between ticks on
the clock moving are *unchanged* in the frame in which that clock is
at rest.

So is the frequency "*unchanged* in the frame in which that clock is at
rest". You understood the first statement. The second statement relates
to the same scenario. Are you deliberately being bloody minded

I should have corrected the first statement as well.

No you are being bloody minded. What else does "the frequency of a
transverse moving clock" possibly mean other than it is moving relative
to you. In the frame in which the clock is at rest it isn't moving.



See the comment below about the absence of ethereal, standalone time.

c/ What the moving clock registers is reduced.

Reduced, relative to a clock at rest in this frame, yes.

Note that there is no ethereal, detached Time that is affected. What
you are *always* doing is comparing the time measured on one clock
between two events with the time measured on another clock between the
same two events.

I never said otherwise



Ignoring Doppler shift (How in practice I don't know but never mind) You
have a moving clock transmitting ticks and locally you have two clocks
one a normal clock counting locally generated ticks and a second
counting transmitted ticks.

You can measure how long the transmitted tick interval is. This is
"measuring the time between two events" as you describe it - the arrival
of one tick and the next. It is this "tick interval" (units seconds)
which dilates.

What is registered on the clock counting the received ticks is a "tick
count".

What time is, is what a clock locally at rest measures.

In note you say "measures" not "indicates".

" We may say of it the following three things:
Set I
(a) The journey occurred in time.
(b) The time of starting was 1 o'clock.
(c) The time occupied by the journey was 2 hours.

The same word, time, is used here in three quite different senses, as
may be seen by considering the corresponding statements about space:
Set II
(a) The journey occurred in space.
(b) The place of starting was London.
(c) The length of (or distance covered by) the journey was 60 miles.

Here we use three different words � space, place, length (or distance),
none of that could be substituted for either of the others without
depriving the sentence of meaning. The same distinctions, thus brought
to light, exist in the set I, but they are obscured by the use
of the same word, 'time', for three quite different ideas.

To distinguish the three meanings of 'time' I will re-express the set I
in the following not unnatural ways:
Set III
(a) The journey occurred in eternity.
(b) The instant of starting was 1 o'clock.
(c) The duration of the journey was 2 hours." Dingle

Note that only (c) has units of seconds. I think that part of the
problem is that we are all familiar with clocks# and think of them as
something which tells time in hours minutes and seconds. In scientific
terms we should perhaps not use the term clock but "duration meter" -
envisaging something with a digital reading which increments at some
interval 1/10^n seconds. The larger n then the better the resolution -
which is started by one detected event and stopped by another event.
Your statement:
"What time is, is what a clock locally at rest measures".
Becomes
What time is, is what a "duration meter" locally at rest measures.
In terms of my scenario the only interval which the duration meter can
measure is the interval between the ticks - the reciprocal of which is
the frequency of the ticks.

#If one is pedantic the strict definition of a "clock" is something
which chimes. If it doesn't chime the correct terminology is a "time-piece".