Light plays a central role in our lives. The electromagnetic (EM) spectrum includes wavelengths ranging from radio waves, microwaves, infrared, the visible spectrum that we perceive as light, ultraviolet, X-rays, and gamma rays. The main source of visible light on the Earth is our Sun, which provides virtually all the energy used by living things. These activities and resources cover some of the different ways we interact with and use light.
International Day of Light - May 16 UNESCO resources