Lacrosse 2

James Nix (
Tue, 06 Jul 1999 19:12:18 -0500

The first was garbled, maybe this will be clearer, apologies  --Jim

Hi Dennis,

        I know...., "reality check!".  Skymap said it was due at 22 seconds
and my stopwatch, (digital to the hundredth) said 13.33.  It is obviously
an estimate but my word processor cannot make a double tilda to indicate
that as "Mathematica" can.  The error is the ubiquitous .2 to account for
reaction time, perhaps it should be .2 + .2 to account for the observation
and the starting of the stopwatch at the "top" of a minute.

        There's an interesting chapter in Paul Davies' "About Time"
(Touchstone 96', Ch 13 "Experimenting with Time") on human reaction time.
The message/impulse may only take .01 sec to get to the brain but to react
takes a little longer. It also varies from person to person. Reaction time
can be less in performing "automated" and repetitive tasks, and a .1
reaction time is common.  The
"now" we experience is estimated at .04 secs.  (Paul is at the University
of Adelaide, maybe Tony can get him to add something to the discussion?)

        I often tape record my remarks on iridium tumbler observations with
the NIST clock ticking in the background and can also hear the beep of the
stopwatch as I mark flashes.  Its interesting to note how long the NIST
signals seem
to take and I can actually hear the beep of the stopwatch mark in between
the NIST
ticks and estimate whether it was a quarter to half second between time
I don't yet know the effects of the tape recording, ie whether or not it is
close to
actual time or a little slower but it is interesting to become "aware" of
time spaces
shorter than a second.

        Maybe nine seconds early with a .4 sec error either way would have
been appropriate :-)

Good to hear from you


Dennis Dinga wrote:
> >
> >Lacrosse 2 running 8.67 sec's early on:
> How in the world are you able to make these measurements within 1/100th
> of a second?  I need to know this trick!   :-)
> >Lacrosse 2
> >1 21147U 91017A   99175.38607241  .00000620  00000-0  10447-3 0    05
> >2 21147  67.9940   0.8071 0005000 193.4022 166.5978 14.69412364    06
> Regards, Dennis
>     /  /  /  /  /      * Dennis Dinga           *
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