Every physical body spontaneously and continuously emits electromagnetic radiation. A natural rainforest emits and absorbs vast quantities of carbon dioxide. Dark matter is a form of matter that neither emits nor absorbs light. Compact surveillance radar emits microwaves from a transmitter and detects any reflected microwaves. Plastic waste emits carbon dioxide when it degrades. A GPR transmitter and antenna emits electromagnetic energy into the ground. This filament emits electrons which ionize the compounds. Because of its temperature, the atmosphere emits infrared radiation. In Thomson scattering a charged particle emits radiation under incident light. A moving electrical charge emits electromagnetic waves of its own. When such an electron decays without external influence, it emits a photon. The body emits its own thermal radiation. This process emits soft beta radiation without a gamma. For example, when a charge is accelerated it emits synchrotron radiation. Earth also emits radiation back into space, but at longer wavelengths that we cannot see.