How is light produced?
What causes light to be light?
Why is light not matter? Does gravity affect light? Is light made up only of photons? What is this light? What Is the Photon Theory of Light? What objects reflect light? Why is light affected by gravity if photons are massless? Can a light period be caused by stress? Why does UV light cause contamination on optics, but not IR light? Essentially, why is photocontamination wavelength dependent? What causes one eye to look either lighter or darker than the other? Why can't we see the light? What happens to the photons when I switch off the light? What happens when ultraviolet light shines on glass? What causes eye color? Is indirect LED light harmful to the eyes? Why do light rays glow up one's face? Is light matter or non-matter? Why does the pupil of our eye contracts in bright light and expands in dim light? Can we see light? Why does light posses a dual nature of both wave and particle only and nothing else? Light needs a medium to travel, so how does sunlight come from space? What does light and darkness represent? What are the advantages of UV light over black light? Refraction of light is an example of which property of photons? What are the health effects of light drinking? Why does light have no mass? Does light have mass? Is light a vector? What causes variations in eye color? Why do ultraviolet lights have radiation?