🚀 go-pugleaf

"Androcles" <Engineer@hogwarts.physics_a> wrote in message 
news:R4Jaj.74630$kt3.70880@fe3.news.blueyonder.co.uk...
>
> "Pentcho Valev" <pvalev@yahoo.com> wrote in message
> news:77495121-f5dc-4968-a75a-bf0940a24863@f3g2000hsg.googlegroups.com...
> : On Dec 20, 11:11, 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."
> :
> : http://www.mathpages.com/rr/s2-07/2-07.htm
> : "It's also worth noting that there is no Doppler shift involved in a
> : Sagnac device..."
>
> Obviously bullshit.

You'd know all about bullshit .. you spout enough of it.

As the source and detector are comoving, there would be no Doppler shift .. 
you only get Doppler shift when the source and detector are relatively 
moving (ie the distance that the light has to travel increases with time).