As waves travel from one medium to another, they will bend. When two or more waves meet they will interfere with each other. In 1676, Olaus Romer measured the speed of light by using observations of Jupiter's inner satellite and comparing the motion of the Earth and the observed and predicted time of Jupiter's eclipse. Years later, at the end of the 19th century, Albert Michelson measured the speed of light with much greater precision. Light is a small part of the electromagnetic spectrum, and all electromagnetic radiation travels at the same speed, 3.00 x 108 meters per second.
Speed is equivalent to the wavelength times the frequency.
A diagram of the electromagnetic spectrum and the associated wavelengths is given below. As you can see in the diagram, the wavelengths falling between approximately 450 nm and 800 nm are classified as visible light. Ultraviolet radiation, the form of electromagnetic radiation associated with skin cancer, has a wavelength very near to the blue color in the spectrum. When we look at a red flower, that flower contains pigments, which absorb all wavelengths of light except for red, so our eye is receiving reflected red wavelengths from the flower. As light waves travel from one medium to another, the wave will bend.