Why do clothes get darker when wet?The optical illusion hiding in your laundry.

From the show

Science Around You

Discover the microscopic physics that transforms a simple spill into a dark stain. Water does not alter the dye in your shirts; it changes how photons travel through the threads. By shifting the refractive index, liquid creates an intricate maze that traps light before it can bounce back to your eyes. Explore how a basic everyday accident is actually a fascinating demonstration of total internal reflection.