🚀 go-pugleaf

On Dec 20, 4:11 am, Pentcho Valev <pva...@yahoo.com> wrote:
> In discussing the Sagnac effect, both relativists and anti-relativists
> make the following mistake:
>

http://www.mathpages.com/rr/s2-07/2-07.htm

> "Quantitatively, if we let w denote the angular speed of the loop,
> then the circumferential tangent speed of the end point is v = wR, and
> the sum of the speeds of the wave front and the receiver at the "end"
> point is c-v in the co-rotating direction and c+v in the counter-
> rotating direction.....This analysis is perfectly valid in both the
> classical and the relativistic contexts."
>
> The values c-v and c+v above are "perfectly valid" only in the
> relativistic context. If by "classical" the author means "Newtonian",
> the analysis is by no means "perfectly valid". According to an
> observer at rest, in the classical context, the speed of light is c+v
> in the co-rotating direction and c-v in the counter-rotating direction
> so the correct text would be:
>
> "Quantitatively, if we let w denote the angular speed of the loop,
> then the circumferential tangent speed of the end point is v = wR, and
> the sum of the speeds of the wave front and the receiver at the "end"
> point is c in the co-rotating direction and c in the counter-rotating
> direction."
>
> Pentcho Valev
> pva...@yahoo.com

<< In the ring laser, four highly reflective deflecting
mirrors form a closed beam path, which in turn encloses
a square surface. When a gas mixture of helium and neon
contained in a stainless-steel tube is excited by
radio waves, the resonator turns into a laser for
two counter-rotating beams. As long as the ring laser
does not move, the beams traveling clockwise and
counterclockwise display identical frequency.
When the ring laser rotates, the frequencies differ
by an amount dependent on the speed of rotation of
the system. >>
http://www.laserfocusworld.com/display_article/83800/12/ARCHI/none/News/Largest-ring-laser-gyroscope-lands-in-Bavaria

"Always Knowing Precisely How Fast the Earth is Turning"
Wettzell Fundamental Research Station
http://www.zeiss.com/C125716F004E0776/0/DB95426F0494AB1DC125717500445CEE/$File/Innovation_10_18.pdf

<<  Professor Ulrich Schreiber of the
Munich Technical University in Germany reported that
his Earth-based, ultra-precise "G" ring laser gyroscope
was able to detect perturbations in the Earth's axis
as a result of the Indonesian earthquake.
This gyroscope--the largest of its kind in the world--contains
a giant glass ceramic disc, 4.25 meters in diameter,
25 centimeters thick and weighing 10 tons. It is located
in a sealed and pressurized chamber, eight meters below
the surface of the Earth, at the Wettzell Fundamental
Research Station in New Zealand. This instrument was
specifically designed to be able to detect changes in
the Earth's rotation within a day. For more information
on the "G" ring laser gyroscope, see a 1996 article on
the Web site of the International Society for Optical
Engineering (SPIE) or download a PDF copy of a 2003 paper
from the Wettzell Fundamental Research Station. >>
http://einstein.stanford.edu/highlights/hl_010705.html

<<The first system was constructed by University of
Canterbury over 1988-1991. The was dubbed C-I (for
Canterbury One). It showed that a square metre ring
laser could operate in single mode and so as a
gyroscope, and that it could be unlocked by Earth
rotation.

The FGS (Forschungsgruppe Satelliengeodäsie)
collaboration  in Germany then joined with us in
a fully international collaboration. The German
partners built a far more precise and stable ring,
C-II. This was installed at Cashmere in 1997, and
developed and upgraded several times since then. >>
http://www.phys.canterbury.ac.nz/research/laser/ring_2000.shtml

Sue...