Dear Crew: I am delighted with the content, care, and thought contained in
this thread. The continual issue of all measurements comprising at least
two numbers (estimate of the quantity measured and an estimate of the
uncertainty of the former) needs always to be dealt with. While the
law-of-large-numbers suggests that a normal distribution is a good
assumption to start with, experience shows that sometimes normal is not
normal. The famous paper by Costa (Dec 1959, Proc. of the (wonderful) IRE)
about communication in the presence of noise and other signals notes that a
Poisson distribution is the appropriate distribution ("Poisson, Shannon, and
the radio amateur").

I had the opportunity at Ohio State to craft a system that measured very
wide BW noise that changed slowly and to add statistical measures to what
was measured. Today, the task would be trivial - a sound card would run
circles around what I did with a voltage to frequency converter,
accumulator, counter-made-into-a-sidereal-clock, punched paper tape, and an
IBM 1620.

It is not enough just to put a number on something. We must remember
the early speed-of-light measurements that had a mean that turned out to be
outside of latter measurement's uncertainty band. An investigation of the
old log books found that not all of the data had been used! When all of the
data was used, the mean was within the more modern measurement's span.

73, Mac N8TT
--
J. Mc Laughlin; Michigan U.S.A.
Home:
"Richard Clark" wrote in message
...
On Thu, 30 Aug 2007 22:46:46 GMT, Owen Duffy wrote: