## Section 4.2: Exploring Wien's Displacement Law

Please wait for the animation to completely load.

Planck's blackbody radiation law,

*u*(λ) = 8π*hc*λ^{−5}/(e^{hc/λ kBT }− 1),

describes how the energy density per wavelength, *u*(λ), varies with wavelength. You may have noticed that for a given temperature, *T*, this curve has a maximum energy density per wavelength at a given wavelength. This wavelength, λ_{max}, depends on the temperature given by the relationship λ_{max}*T* = constant. The relationship between λ_{max} and temperature is called Wien's displacement law. Restart.

Vary the temperature using the text box and the "set temperature" button to verify Wien's displacement law. What is the constant in Wien's displacement law? Hint: Plot λ_{max} (in meters) versus 1/*T* and determine the slope of this graph.