Re: Einstein ever defined TIME?

From: Paul B. Andersen (paul.b.andersen_at_hia.no)
Date: 10/22/04 

Date: Fri, 22 Oct 2004 14:54:12 +0200

> >> >> >Henri Wilson wrote:
> >> >> >> As far as I know, I am the only person who has ever provided a decent
> >> >> >> definition of time.
> >> >> >>
> >> >> >> Time, like space, is a basic dimension by which we describe events in the
> >> >> >> universe.
> >> >> >> It has three subdimensions, the ratios of which allow concepts like 'timeflow'
> >> >> >> to have a noncircular meaning.

[..]

"Henri Wilson" wrote:
> "Paul B. Andersen" wrote:
> >"Henri Wilson" wrote:
> >> "Paul B. Andersen" wrote:
> >> >I snap my fingers twice.
> >> >I challenge you to explain how to measure the "time"
> >> >between those two events, where "time" is according
> >> >to your definition.
> >> >
> >> >Remember, this is a physics NG, and we are only
> >> >interested in definitions of concepts which can be
> >> >used in physics.

[..]

> >> To measure the time interval between the snapping of your fingers (twice) you
> >> use a clock. You arrange for its rate to be fixed wrt a certain stable
> >> periodicity, such as the rotation of Jupiter, then you arrange for the snapping
> >> of your fingers to firstly start the clock and then stop it.
> >
> >How do you from your definition above conclude that
> >"a clock with a certain stable periodicity" measures "time"?
>
> A clock indicates time instant.
> A perfect clock will always read the 'time interval' after a certain arbitrary
> zero.

So "a clock" is per definition an instrument which
measures "time" according to your definition.

So the question is:
Is it possible to make a real, physical "clock",
at least in principle?

> It does this by integrating its own 'ticking rate', dt2/dt1, wrt t1.
> In other words, it just adds up the number of ticks it makes.
>
> Unfortunately, no clock is perfect.

You have missed the point completely.
Is there any reason whatsoever to think that any
natural repeating process will have a period
which is stable according to YOUR definition of "time"?

There is nothing in your "decent" definition which say
that the amount of "time" should be equal for two different
cycles of - say a specific spectral line (or whatever).

And there is nothing in your definition which says
anything about if the same natural process can
be assumed to take the same amount of "time"
everywhere in the universe.

So exactly how do you measure "time" in the real
physical world?

Paul

Relevant Pages

  • Re: Clock synch
    ... Einstein's definition for time that "time is what a clock ... clock second co-moving with the ruler. ... So your assertion that the existence of a perfect clock is false. ...
    (sci.physics.relativity)
  • Re: Clock synch
    ... Einstein's definition for time that "time is what a clock measures". ... clock second co-moving with the ruler. ... So your assertion that the existence of a perfect clock is false. ...
    (sci.physics.relativity)
  • Re: Clock synch
    ... Einstein's definition for time that "time is what a clock ... in different frames. ... clock second co-moving with the ruler. ... By definition a perfect clock will run at the same rate in all ...
    (sci.physics.relativity)
  • Re: Clock synch
    ... Einstein's definition for time that "time is what a clock ... clock second co-moving with the ruler. ... that a clock second doesn't have the same duration in different frames" ... So your assertion that the existence of a perfect clock is false. ...
    (sci.physics.relativity)
  • Re: Einstein ever defined TIME?
    ... >> diffferent conditions of gravity and velocity. ... >> However this concept is not related to the stupid GR claim that a clock will ... You arrange for its rate to be fixed wrt a certain stable ... A perfect clock will always read the 'time interval' after a certain arbitrary ...
    (sci.physics.relativity)