In order to obtain a negative result, we should have Δ"LA"−Δ"LB"=0. However, it can be seen that both formulas only cancel each other as long as the velocities are the same ("vA"="vB"). But if the velocities are different, then Δ"LA" and Δ"LB" are no longer equal. (The Michelson–Morley experiment isn't affected by velocity changes since the difference between "L"L and "L"T is zero. Therefore, the MM experiment only tests whether the speed of light depends on the "orientation" of the apparatus.) But in the Kennedy–Thorndike experiment, the lengths "L"L and "L"T are different from the outset, so it is also capable of measuring the dependence of the speed of light on the "velocity" of the apparatus.