Säteilylämpöön

Säteilylämpöön refers to heat transfer through electromagnetic radiation. Unlike conduction and convection, which require a medium to transfer heat, radiation can travel through a vacuum. The primary source of radiation heat transfer for Earth is the Sun. All objects with a temperature above absolute zero emit thermal radiation. The intensity and spectrum of this radiation depend on the object's temperature. Hotter objects emit more radiation and at shorter wavelengths.

When this radiation strikes another object, it can be absorbed, reflected, or transmitted. The absorbed radiation increases the internal energy of the object, leading to a rise in its temperature. This process is fundamental to understanding how the Earth's atmosphere is heated, how greenhouses work, and how various technologies like solar panels function.

Examples of säteilylämpöön in everyday life include feeling the warmth of a fire without being directly in the path of its flames, or the heat felt from a hot stove burner from a distance. In space, where there is no atmosphere, objects are heated and cooled primarily through radiation. The color and surface properties of an object also play a significant role in how much radiation it absorbs or reflects, influencing its temperature. Dark, matte surfaces are generally good absorbers and emitters of radiation, while light, shiny surfaces are good reflectors.