Physlet by Wolfgang Christian

Instructions on how to use the animation below-
• Slide the bar appearing at the bottom of the animation in order to set the temperature. The value of the temperature, in units of Kelvin, is shown to the right of the sliding bar and in the border on the left side of the animation.
• You may change the location of the maximum of the energy spectrum by dragging the "color spectrum", appearing below the curve, to the left or right.
• The energy density (y axis) is given in units of Joules/meter3. The actual value of the energy density is obtained by multiplying the y coordinate by the power of ten appearing near the top of the y axis.
• The length (x axis) is given in units of meters. The actual value of the length is obtained by multiplying the x coordinate by the power of ten appearing near the bottom (and to the right) of the x axis.
• The actual color seen by an observer looking at the thermal radiator is displayed in the disc appearing above the word Appearance in the border on the left side of the animation.