Where Does Radiant Energy Come From?

The sun is the primary source of radiant energy on Earth, according to Explorit Science Center. Radiant energy is a type of electromagnetic radiation. Upon leaving the sun, this energy reaches Earth - a distance of almost 93 million miles - in just eight minutes, because all electromagnetic radiation travels at the speed of light, which is 186,000 miles per second.

Solar radiant energy includes several wavelengths. Most solar radiation transmits from the sun in the form of visible light. Outside the visible spectra of light, the sun radiates infrared energy in the form of heat and ultraviolet rays, which cause sunburn.

The radiant energy from the sun is stored in many biological processes. Leaves on trees use sunlight to convert carbon dioxide into glucose to store energy. Ultimately, humans, who are at the top of the food chain, use this stored energy.

The Earth does not receive all the radiant energy produced by the sun. Due to its spherical shape, the sun emits energy in all directions, but most of this energy dissipates into space.

Energy in the form of heat is also stored on Earth, where it radiates again. This thermal energy increases the motion of atoms in matter. Passive solar heating involves storing such energy in a thermal mass so that radiant energy warms the area when sunlight is not available.