Page:Michelson1904.djvu/4

Rh $$v$$ is the velocity of the earth in its orbit, $$\mathrm R$$ the radius of earth's orbit, and $$\delta$$ the sun's declination.

If $$\mathrm A$$=10×10 kilometres,

$$\begin{alignat}{3} v / \mathrm{V} =&\ 10^{-4}, & \mathrm{R} =&\ 1.5 \times 10^{11}, & \lambda =&\ 5 \times 10^{-7} \\ \sin \phi =&\ 0.7, & \quad\cos \delta =&\ 1, & \text{then }\Delta =&\ 0.37 \end{alignat}$$

To obtain this displacement would require a circuit 40 kilometres in length.