Numerous computational and spectroscopic studies have demonstrated the decisive role played by nonadiabatic coupling in photochemical reactions. Nonadiabatic coupling drives photochemistry when potential energy surfaces are nearly degenerate at avoided crossings or truly degenerate at unavoided crossings. The dynamics induced by nonadiabatic…

Photoisomerization of conjugated systems is a common pathway for photomechanical energy conversion in biological chromophores. Such reactions are mediated by conical intersections (CIs)--points of degeneracy between different potential energy surfaces, which efficiently funnel population between electronic states. There are many examples of a…

The United States has explored the solar system with automated spacecraft and human-crewed expeditions that have produced a quantum leap in our knowledge and understanding of the solar system. Through the electronic sight and other "senses" of our automated spacecraft, color and complexion have been given to worlds that for centuries…

Discusses the scientific knowledge available to Christopher Columbus and how it influenced his geographically flawed, yet historically significant, decision to sail west in order to travel east. Factors discussed include Aristotle's conclusion that the earth was round, early measurements of latitude and longitude, and early map-making attempts.…