There's a featured video linked from the article: "Theoretical Physicist Explains Time in 5 Levels of Difficulty" [1] with physicist Brian Greene. At minute 5:

There's a featured video linked from the article: "Theoretical Physicist Explains Time in 5 Levels of Difficulty" [1] with physicist Brian Greene. At minute 5:52 he describes the light clock, and at 6:36 he computes the ratio between a stationary and a moving clock. In the first passage, he writes T_s / T_m = D / L. Shouldn't it be the opposite (i.e. L / D), since D is the distance that a photon travels in the moving clock? Can anyone clarify that, please? [1] https://www.wired.com/video/watch/theoretical-physicist-explains-time-in-5-levels-of-difficulty https://www.wired.com/video/watch/theoretical-physicist-expl...