Re: Lacrosse 2 & 3

James Nix (
Tue, 06 Jul 1999 18:18:01 -0500

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 Human reaction
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
at .04 secs.  (Paul is at the University of Adelaide, maybe Tony can get him to
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
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
whether it was a quarter to half second between time signals. I don't yet know
effects of the tape recording, ie whether or not it is close to actual time or a
slower but it is interesting to become "aware" of time spaces shorter than a

	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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