The transfer of energy by electromagnetic waves is called radiation. These waves can travel through space from the Sun to Earth. On Earth, radiation includes visible, ultraviolet, and infrared waves. Our eyes cannot see infrared radiation. Objects give off visible light when they are heated to 600°C. As the temperature rises to thousands of degrees, the light becomes blue-white. When objects absorb electromagnetic energy, they might change from one state of matter to another, such as snow melting in sunshine. Heat can travel through solids by conduction. It can travel through liquids and gases by another heat transfer called convection. For example, in the atmosphere, warm air rises upward.