When video recordings of Ravi Janardan's computer-science course at the University of Minnesota-Twin Cities first went online, the students loved it. Instead of dragging themselves out of bed for the 8 a.m. lectures, many started skipping classes and watching the recordings instead. Recording lectures is becoming more and more common, and many…

A molecule coming from outside an organism can form a ligand-receptor complex. Upon its formation, a message is transmitted, for example, to certain cells. In this way, two enantiomers can emit messages that differ, either quantitatively or qualitatively. In the present article, these facts are taken as a common basis for the actions of chiral…