Collaboration Day 9 on March 16, 2017 Descartes diffraction longitudinal spectral distribution Newton's rings theory of the rainbow +
Collaboration Day 8 on March 01, 2017 Descartes diffraction experimentum crucis longitudinal propagation longitudinal spectral distribution objective prismatic experiments Snell's law subjective prismatic experiment +
Collaboration Day 6 on February 11, 2017 Alexander's Dark Band Descartes Goethe objective prismatic experiments rainbow subjective prismatic experiment +
Collaboration Day 4 on September 11, 2016 Alexander's Dark Band Descartes double rainbow primary rainbow secondary rainbow +