Blackbody radiation

Constants

$DefaultFont={"Times-Bold",14};

h = 6.62618 10^(-34) J s;
c = 2.997925 10^(8) m s^-1;
kb = 1.38066 10^(-23) J K^-1;

Energy density

For the Plank distribution function, we use the wavelength divided by nm as "l".  Thus the energy density is given in KJ/m^4.

den[2000,1646]

Plot[den[x,1646]/(J/m^4),{x,1,5000},Frame->True,RotateLabel->False,PlotStyle->Hue[.0],
     FrameLabel->{"wavelength/nm","J / /\!\(m\^4\)"}]

Plot[den[x,2000]/(J/m^4),{x,1,5000},Frame->True,RotateLabel->False,PlotStyle->Hue[.2],
     FrameLabel->{"wavelength/nm","J / /\!\(m\^4\)"}]

Plot[{den[x,5000]/(J/m^4),den[x,3000]/(J/m^4)},{x,1,4000},PlotRange->All,PlotStyle->{{Hue[.4]},{Hue[.6]}},Frame->True,RotateLabel->False,
      FrameLabel->{"wavelength/nm","J / /\!\(m\^4\)"}]

den[200,12000]

Plot3D[den[l,T]/(J/m^4),{l,1,3000},{T,3000,5000},PlotPoints->50,PlotRange->All]
         

den[500,5000]

Created by Mathematica  (September 7, 2006)