The tuning fork was used with a clock. The clock was checked against
astronomical measurements.
http://www.schoolphysics.co.uk/age16-19/Wave%20properties/Wave%20properties/text/Speed_of%20light/index.html
http://www.nhn.ou.edu/~johnson/Education/Juniorlab/C_Speed/2007-PhysToday-RefFrame-Michelson.pdf
http://www.loc.gov/item/magbellbib002940 synchronizing two forks, letter to
Bell.
http://www.otherhand.org/home-page/physics/historical-speed-of-light-measurements-in-southern-california/the-mount-wilson-station-1922-1928/
John WA4WDL
--------------------------------------------------
From: "Jim Lux" <jim...@earthlink.net>
Sent: Monday, June 24, 2013 4:55 PM
To: <time-nuts@febo.com>
Subject: Re: [time-nuts] Measuring speed of light or reproducing a metre
On 6/24/13 10:08 AM, Chris Albertson wrote:
Using only "moderately" accurate equipment, like mechanical clocks and
meter sticks Albert Michelson has able to measure the speed of light and
determine it was a constant in all directions. It was this work the
prompted Albert Einstein to think about what t means for C to be
constant.
They were working at about the turn of the last century or before 1890 to
about 1905 and did not have lasers or HP universal contours. They used
sunlight.
One experiment was done here where I live up at the Mt. Wilson
Observatory.
They put light from a slit onto to a rotating mirror and then bounced it
off a fixed mirror back to the rotating one. If the speed were infinate
the light would go right back up the slit. But in reality the light
misses
because the rotating mirror moves a little while the beam is in flight.
Isn't that the Fizeau technique, which antedates Michelson's?
The advantage of this is that it is a direct measurement of the speed of
light that does not depend on many assumptions and can be done with
technology that was available in the late 1800's One big limitation is
the atmosphere. You need very stable air over the long path length
You need to know the rotation rate of the toothed cog or rotating mirror,
don't you?
You could get that by matching against something like a tuning fork, but
how do you measure the frequency of the tuning fork.
This was the experiment that got Einstein thinking. He said he started
at
age 16 to think about how the light from a moving lamp could be the same
speed as one from a stationary lamp. It was total non-sense and
impossible
at the time. We have to remember that those experiments at the time
were
are considered to be "Failed Experiments" because "C" could not be
constant.
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