Eq. (5) should be:
I / I0 = (E / E1) squared
This is just a minor slip and does not affect the note. This equation gives the power absorption coefficient of the Beer Lambert law as:
alpha = omega eps” / (n’ c)
where omega is the angular frequency, eps” is the dielectric loss, n’ is the real part of the refractive index, and c is the vacuum speed of light. This equation is used in several hundred of the early Omnia Opera papers and books on www.aias.us. The second equation above was among the very first things I studied for my Ph. D. – during the summer of 1971 after I graduated the top first in chemistry. I was given the Ph. D. Thesis of G. W. F. Pardoe to study by Mansel Davies. It contained a description of the Debye plateau – the limit of the Debye theory where it becomes inapplicable in the far infra red. The Debye theory produces an unphysical plateau from the second of the above equations. I corrected the Debye theory using the memory function to produce an accurate description of the power absorption coefficient of liquids and other materials in the far infra red, and extended the method using molecular dynamics computer simulation which I helped pioneer at Oxford and Aberystwyth. The prestigious Harrison Memorial Prize and Meldola Medal of the Royal Society of Chemistry was awarded to me for this work. Those prizes are worth a lot more now. I became known as “Mr Far Infra Red”, being a lifelong Bevanite Socialist (a raving left wing radical). So now this same type of equation has shown that photon mass must be non zero in any absorption, including of course the far infra red.