Physics
Wien's Displacement Law
Quick fact
The hotter an object is, the shorter the wavelength of its peak thermal emission—this is why stars appear different colors at different temperatures.
Why this is interesting
Have you ever noticed that a glowing ember turns red when it's cool, but white when it's hot? This is a simple example of Wien’s displacement law in action.
Read the full explanation
Understanding Wien's Displacement Law
Wien's displacement law explains that as an object gets warmer, it emits more energy and shifts from longer wavelengths (like red) to shorter ones (like blue or white). This happens because the distribution of emitted light changes with temperature, with a peak wavelength moving toward the visible spectrum’s shorter end.
A deeper explanation
Wien's displacement law arises from the behavior of blackbody radiation. As an object is heated, its energy emission shifts to higher frequencies and shorter wavelengths. The law states that the product of the peak wavelength and the temperature is constant, which allows us to determine the temperature of distant objects like stars by analyzing their emitted light spectrum.