I think maybe they forgot to define all quantities. (If you were curious, the Beer-Lambert law relates to the absorption of light by a solution and is the basis of spectrophotometry... though I don't think I could write out the actual equation from memory. Guess I'll just Google it.)
I am currently a postdoctoral research fellow in Memphis, TN. Though the blog tends to cover a lot of popular psychology, my areas of research include, or have included:brain injury, auditory neurobiology, neuroendocrinology, and developmental neurobiology.