(distance_{1} − distance_{2}) = \frac{1}{2} λ , \frac{3}{2} λ , \frac{5}{2} λ , …

(2L_{1} − 2L_{2}) = \frac{1}{2} λ , \frac{3}{2} λ , \frac{5}{2} λ , …

(L_{1} − L_{2}) = \frac{1}{4} λ , \frac{3}{4} λ , \frac{5}{4} λ , …

\begin{aligned}Period P & = \frac{2πR}{v} \\ & = 0.005 s \end{aligned}

strain h ∼ \frac{GM}{c^{2}} \frac{1}{D} (\frac{v}{c} )^{2}

length change Δx = h L