MyBlackBodyApplet (will appear below in a Java enabled browser)

See this Applet (modified a little by Wolfgang Christian) on the Physlets page.

This applet shows visually the results predicted by the Stefan-Boltzmann law. The Stefan-Boltzmann law predicts intensity output across varying wavelengths as a function of temperature. It describes the "ideal" blackbody radiator. Our Sun is an example of a "real" blackbody radiator. It's spectrum isn't as smooth as the "ideal" and is pitted and bumpy due to real-world conditions (including, but not limited to, absorption of the radiation en route to the earth).

Temperature of the blackbody can be set in two ways. The first is to vary the actual temperature of the object, by moving the slider back and forth (from near zero degrees to a maximum of 10,000 degrees). The second way is to move the peak wavelength by draggin on the graph itself. Temperature can be related to peak wavelength according to Wien's Law (T = 2.9E-3/lambdamax)--which can lead to temperatures much in excess of 10,000 Kelvin.

A simulation of the visible spectrum is displayed under the curve, corresponding to 400 (blue), 560 (green), and 700 (red) values. The colored circles on the left represent the percent of each color present and a simulation of the total color of the object.

This applet is fully scriptable and takes several <PARAM> values to set it's initial layout.


For more information contact Mike Lee or Wolfgang Christian.