BlackBody Physlet^®  requires a Java 1.1 capable browser with JavaScript to Java scripting capability. BlackBody is free for non-commercial educational use.

Click drag within the spectral distribution.

Temperature of the BlackBody applet can be set in two ways. The first is to set the actual temperature typing in a new value in the text field below.  The applet will then show you the spectrum and the apparent color of the object. The second way is to move the peak wavelength by click-dragging on the graph itself. Temperature can be related to peak wavelength according to Wien's Law (T = 2.9E-3/lambda_max)--which can lead to temperatures much in excess of 10,000 Kelvin.  Note the change is scale on the y axis. The total energy radiated by a black body increases dramatically with temperature although we autoscale the graph to highlight the change in color.

A simulation of the visible spectrum is displayed under the curve, corresponding to 400 (blue), 500 (green), and 600 (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.