🚀 go-pugleaf

matmcinn@nuscc.nus.sg (Mcinnes B T (Dr)) writes:
>I am holding in my hand a baloney sandwich. I hereby declare that this
>is an instance of a clock. Now I note that as the baloney sandwich
>decreases, so does my hunger. Since time is what a clock measures, I
>deduce that: Time is hunger.
>
>In short, this definition of time is a load of baloney. Time is NOT what
>you measure with a clock. Time is the length of timelike worldlines. Its
>definition has nothing to do with the way you happen to measure it, which
>is a mere technological bagatelle.

Interesting.  I think Einstein would have disagreed with you.  In fact, if
memory serves me correctly, he himself once said that "Time is that which
a clock measures."  (Granted, this is an argument by appeal to authority,
but I don't think that such tactics are entirely without merit when the
authority cited is _the_ authority.)


Dr. Mcinnes later adds:
>I am a serious person with a vast store of good will. But you know that
>baloney is not a clock because you know that it doesn't measure time.
>That's because you know that time exists independently of devices used
>to measure it. It's about time [so to speak] to drive a stake [or is
>that steak?] through the heart of operationalism. .

Of course we agree that some clocks are better than others, and we do have
an abstract concept of time which allows us to talk about measurement
errors of even the most precise atomic clock.  Furthermore, without an
abstract concept of time, how would one know how to design a good clock?
One might wind up with a baloney instead.  ;)

But it is very important to acknowledge that time _is_ what clocks
measure, and that length _is_ what meter sticks measure, lest one be
mislead by a faulty abstraction.  Einstein's thought experiments involved
putting real clocks, meter sticks and observers in various situations and
determining what would happen to them.  If he hadn't believed that time is
what a clock measures, he would never have formulated relativity; he would
still be trying to explain why his clocks were misbehaving.

Remember Mach's Principle.

--
Phil Hees
hees@cubic.com