Page:WitteSagnac1.djvu/5

 thus it is:

and the phase change $$x$$ at wavelength $$\lambda$$, is given by:

This formula is also to be applied in our case, it must only be considered that the direction of the translatory velocity $$v$$ (tangent)



and that of light (polygon side) do not coincide, it is thus (as it follows from Fig. 2) substituted instead of $$v$$:

$v\cdot\cos\frac{\vartheta}{2}$

where $$\vartheta$$ denotes the polygon side of the corresponding central-angle.

If one substitutes this value, than the phase difference $$2\cdot x$$, mutually experienced by rays $$R$$ and $$L$$ due to the relative aether stream, is:

Finally one can substitute value 1) for velocity $$v$$ of the relative aether stream with rotating number $$N$$ and circle radius $$r$$, then it is given:

$2\cdot x=\frac{4\pi N}{c\cdot\lambda}\cdot U\cdot r\cdot\cos\frac{\vartheta}{2}$