https://www.khanacademy.org/science/ms-physics/x1baed5db7c1bb50b:waves/x1baed5db7c1bb50b:electromagnetic-waves/v/electromagnetic-waves-and-matter 2025-07-01T10:10:08.145512912Z Electromagnetic waves and matter Electromagnetic (light) waves travel along straight line paths. We can model these paths using rays. When a light ray encounters a boundary between different materials, the light can be reflected, absorbed, and/or transmitted. Most everyday objects don't emit their own visible light. We see these objects when visible light from a source reflects off of the object and into our eyes. Objects that absorb all colors of visible light appear black. Mahesh Shenoy video https://cdn.kastatic.org/ka_thumbnails_cache/732a6dc9-a8b8-46dd-81e7-022521e69b88_1280_720_base.png Electromagnetic waves and matter Electromagnetic (light) waves travel along straight line paths. We can model these paths using rays. When a light ray encounters a boundary between different materials, the light can be reflected, absorbed, and/or transmitted. Most everyday objects don't emit their own visible light. We see these objects when visible light from a source reflects off of the object and into our eyes. Objects that absorb all colors of visible light appear black. https://cdn.kastatic.org/ka-youtube-converted/nXuPL8KD2SU.mp4/nXuPL8KD2SU.mp4 456 Apparent colours of objects https://www.khanacademy.org/science/organic-chemistry/spectroscopy-jay/uv-vis-spectroscopy/v/absorption-in-the-visible-region 2023-09-10T17:11:17.624018169Z Absorption in the visible region Explore the physical basis of our perception of color through the example of beta carotene, the molecule that gives carrots their orange color. Beta carotene absorbs light in the visible region of the electromagnetic spectrum at wavelengths of approximately 450 to 500 nanometers, which corresponds to blue light. As a result, the orange wavelengths are reflected, making beta carotene appear orange to our eyes. Jay video https://cdn.kastatic.org/googleusercontent/-BVqSwaO5Of4Om478NOZvpaxjidbpl8aPEJftZ4hZwyzP0Rmv_1nlC30V1l0zqpWmvM9FnLJ-qRmg3JdkbJBfsP8 Absorption in the visible region Explore the physical basis of our perception of color through the example of beta carotene, the molecule that gives carrots their orange color. Beta carotene absorbs light in the visible region of the electromagnetic spectrum at wavelengths of approximately 450 to 500 nanometers, which corresponds to blue light. As a result, the orange wavelengths are reflected, making beta carotene appear orange to our eyes. https://cdn.kastatic.org/ka-youtube-converted/5HMMfiyszjo.mp4/5HMMfiyszjo.mp4 311 Apparent colours of objects