From “Minute Physics”. ( YouTube / Nebula )

Go to https://brilliant.org/minutephysics to try everything Brilliant has to offer for free for a full 30 days, and also get 20% off your annual premium subscription!

If you take a piece of white paper into different lighting conditions, it will be an objectively different color in each situation, but our brains are clever enough to make us feel like it’s still white – it’s still the same piece of paper, after all. To match our experience, cameras have to do this, too, "balancing" the colors of an image so that a white object looks white under a given light, rather than some other color. And the typical unit to measure the color of a light is the Kelvin. Which is weird, because Kelvin is a unit for measuring temperature, not color. What temperature and the color in a photograph have to do with each other comes down to history and physics.

Support MinutePhysics on Patreon! http://www.patreon.com/minutephysics
Link to Patreon Supporters: http://www.minutephysics.com/supporters/

MinutePhysics is on twitter – @minutephysics
And facebook – http://facebook.com/minutephysics

Minute Physics provides an energetic and entertaining view of old and new problems in physics — all in a minute!

Created by Henry Reich