The Kid Should See This

The World in UV

See The World in Ultraviolet, a similar but strange view compared to what our human eyes perceive in the visible spectrum. In this Veritasium video, Derek Muller explores how the ultraviolet makes eyeglasses, flowers, human skin, arctic sea pups, and the blue sky look different than what we’re used to seeing in visible light. From the video notes:

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.

Plus, ‘Physics Girl’ Dianna Cowern joins him to help demonstrate how different sunscreens absorb and reflect ultraviolet light.

Follow this video with How the Sun Sees You: Revealing human skin in ultraviolet light, Summertime Science: Sunburn, Sweat, and Wrinkly Fingers, and What Really Causes Sunburns?

Bonus: Invisible London, a near-infrared look at the British capital.

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