UV cameras expose a hidden world and reveal the incompleteness of our perception. In summary, ultraviolet light interacts differently with matter for a number of reasons: 1. Some pigments selectively absorb UV so they may appear white in the visible but dark in the UV. The pigments usually dissipate the UV energy as heat, though the breaking of bonds can also occur. 2. Fluorescent molecules absorb UV light and re-radiate that energy as visible light. This makes them look dark in the UV but glowing under black light. 3. Ultraviolet light scatters more than visible light because the wavelength is shorter and Raleigh scattering is proportional to the reciprocal of wavelength to the power of four. Special thanks to HHMI BioInteractive for their awesome animations of melanocytes and how the melanin in melanosomes protect your DNA.
To see the full video explaining how we get our skin color, check out: https://www.youtube.com/watch?v=VC0TL…
The Physics Girl looks at sunscreen: https://youtu.be/GRD-xvlhGMc
How to make sunscreen from scratch: https://youtu.be/lMXAY5F28L0