L = v \frac{1}{2}(Δt)_{red}

R = \sqrt{H^{2} + (\frac{1}{2}vΔt_{r})^{2}}

Δt_{r} = \frac{2R}{c} = \frac{2\sqrt{H^{2} + (\frac{1}{2}vΔt_{r})^{2}}}{c}

Δt_{r} = \frac{2H}{c} \frac{1}{\sqrt{1 − (\frac{v^{2}}{c^{2}}} )}

γ ≡ \frac{1}{\sqrt{1 − (\frac{v^{2}}{c^{2}}} )}

\begin{aligned}Δt_{b} & = \frac{2H}{c} \\ Δt_{r} & = \frac{2H}{c} γ \end{aligned}