Thin Lenses

"An intellectual is someone whose mind watches itself"
Albert Camus

lens types

"There are 1011 stars in the galaxy. That used to be a huge number.But it's only a hundred billion. It's less than the national
deficit! We used to call them astronomical numbers. Now we should call them economical numbers."
Richard Feynman


Dr. C. L. Davis
Physics Department
University of Louisville