What is the relationship between temperature and radiation emission?

The relationship between temperature and radiation emission is that hotter objects emit more radiation and at shorter wavelengths.

When an object is heated, it emits radiation in the form of electromagnetic waves. This radiation can be in the form of visible light, infrared, ultraviolet, or other types of electromagnetic waves. The amount and type of radiation emitted depend on the temperature of the object. As the temperature increases, the object emits more radiation overall. This is because the particles within the object have more energy and move more vigorously, causing more frequent and energetic emissions of radiation.

One important concept to understand is the idea of blackbody radiation. A blackbody is an idealised object that absorbs all radiation that falls on it and emits radiation at a rate that depends only on its temperature. The relationship between temperature and radiation for a blackbody is described by Planck's law, which shows that as the temperature of a blackbody increases, it emits more radiation at every wavelength. However, the peak wavelength, where the most radiation is emitted, shifts to shorter wavelengths as the temperature rises. This is known as Wien's displacement law.

For example, a piece of metal heated to a few hundred degrees Celsius will glow red, emitting mostly in the infrared and red parts of the spectrum. If it is heated further to a few thousand degrees, it will glow white, emitting across the visible spectrum and into the ultraviolet. This is why stars, which are extremely hot, emit light that we can see and also ultraviolet radiation.

In summary, the hotter an object gets, the more radiation it emits, and the peak of this radiation moves to shorter wavelengths. This fundamental principle helps us understand a wide range of phenomena, from the glow of a hot stove to the light emitted by stars.