Light

Light and Absorption

Light is a form of energy known as electromagnetic energy. Electromagnetic energy travels in waves which are disturbances of electrical and magnetic fields. Visible light and other forms of electromagnetic energy radiate through space as discrete packages called photons. We perceive different wavelengths of visible light as different colors. White light is composed of a mixture of wavelengths which can be sorted into its componet colors by bending the light of different wavelengths with a prisim.

As light meets matter, it may be reflected, transmitted, or absorbed. The substances within plants and algae that absorb visible light are called pigments. The ability of a pigment to absorb various wavelengths of light can be measured and graphed as an absorption spectrum. Leaves appear green because their light-absorbing pigment, chlorophyll, absorbs and utilizes red and blue light, at wavelengths of 700 nm and 400 nm, while transmitting and reflecting green light at wavelengths between 500 and 600 nm.