Re: Clock Properties

guido wrote:
"Tom Roberts" <:
To be considered as a clock in the sense physicists use the word, one
must include the pendulum's relationship with the gravitational source.
This makes it impractical to use for most investigations of clock tick
rate.

Might we say that there are 'gravitational' clocks, like the pendulum, and
non-gravitational ones?

Sure. There are various techniques for creating clocks. But not all of them fit easily into such a classification: Consider the clock consisting of a rotating isolated sphere with a mark on its surface, and a counter that counts the mark going by. How would this be classified? Note that the signals received from pulsars (rotating neutron stars) are essentially like that, and rank among the most accurate time keepers known (better than most atomic clocks).


The latter would imply a cyclic motion induced by
non-grav., eg, electromagnetic, forces. Even so, there might be different
families responding to different forces?

There might. After all, just about anything is possible.... But actual measurements of clocks using EM forces (atomic clocks), weak forces (muon decay), and strong forces (nuclear spin resonance) all behave similarly for various changes in their environment (e.g. rapidly moving frames).


All the other clocks that we normally think of (in this context, anyway)
are self contained, and their tick rate is not directly dependent on any
external quantity; that is NOT true for the pendulum "clock".

Would that imply that gravitation-sensitive aging would differ from, eg,
el.magn. sensitive aging?

We have no way to measure aging via gravitation. All our physiological functions are electromagnetic. See above for why the type of clock does not matter.


Tom Roberts
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