Movie S5.

Discrete movement of thiol–water interface, shown in Fig. 4. Left, flat-field image; Center, consecutive subtraction image; Right, composite image. Each frame is the average of 50 images. Playback speed: 20 fps. Actual speed: 40 Hz. Contrast scale: Left, +0.95 to +1.05; Center, −0.01 to +0.03; Right, −0.05 to +1.05.