I thought that the frequency of light was directly inverse to the wavelength by a constant. In other words, I assumed that graphing the frequency of light as a function of wavelength would be a straight inverse line. Because of that, the graphs for the distribution of light from the sun as functions of frequency and wavelength would be exactly the same, but reversed. Yet, this is not what is reported in the linked article. Even more confusing to me is that the different functions peak at different light. When as a function of frequency, the light peaks at infrared. When as a function of wavelength, the light peaks at violet.
What am I misunderstanding? Is the frequency of light not directly proportional to it’s wavelength? Or is this something to do with the way we are measuring the light from the Sun?
In a vacuum c=nu*lamba or the speed of light is equal to the frequency times wavelength. So nu=c/lamba. If you plot 1/x, you don’t get a straight inverse line. You get a multiplicative inverse. So not only is the data flipped, but it also has a distortion that will compress portions and stretch others.
As to why the functions peak at different colors, I believe this is due to an oddity in the axis units. Notice how the irradiance is in W/m^2/nm in the first and W/m^2/THz in the second. Are you familiar with histograms? Think of it like binning the power intensity per nm bin and power intensity per THz bin. Since THz and nm are inversely related, the width of the bins is changing when the basis is changed. This leads to another stretching in the data that is less intuitive.