A head transplant is a surgical operation involving the replacement of one organism’s head with another’s. The first successful head transplant took place in the 1970s, when the head of a monkey was transplanted onto another’s body. The animal retained most of its senses but was paralyzed below the attachment site. Though still hypothetical for humans, proponents believe the procedure can help people facing widespread organ failure. What has prevented human head transplants from taking place? Discuss
Source: The Free Dictionary
In the final year of his life, prolific composer Wolfgang Amadeus Mozart produced the opera Die Zauberflöte—The Magic Flute—featuring a libretto by the actor Emmanuel Schikaneder. The work is considered a singspiel—an opera in German that contains spoken dialogue and is usually comic in tone. Mozart brought this form of light musical entertainment to a height of lyrical and symbolic art. How much longer did Mozart live after The Magic Flute debuted? 
San Geronimo Feast Day is the feast day for 
After receiving a doctorate in physics in Germany in 1906, Geiger traveled to England, where he assisted chemist Ernest Rutherford. In 1908, they designed an instrument to detect and count alpha particles, positively charged ionizing particles produced by radioactive decay. He then returned to Germany, directing radiation research at several universities. Two decades later, Geiger developed the sensitive, portable radiation counter that now bears his name. Geiger was a member of what “club”? 
Among the best primary sources on Aztec culture, Aztec codices contain firsthand accounts of the civilization’s history and religion. While the pre-Colombian codices are largely pictorial, later colonial era codices contain Aztec pictograms, as well as Aztec, Spanish, and occasionally Latin writings. Though there are few surviving pre-conquest codices, the tradition endured the transition to colonial culture, and about 500 such works survive today. What massacre is described in the Aubin Codex? 
Abbreviated as CERN after the original French name, the European Organization for Nuclear Research is the world’s largest particle physics laboratory. CERN’s activities are sponsored by 20 European countries. It was there that the World Wide Web—developed to promote scientific collaboration by facilitating information sharing—was invented in the 1990s. CERN’s latest project, the Large Hadron Collider, is, among other things, being used to discover the hypothesized Higgs boson, which is what?