Ballroom dance, a type of social dancing performed by couples, was once reserved for the privileged classes. But in the 20th century, husband-and-wife dance team Vernon and Irene Castle and film duo Fred Astaire and Ginger Rogers brought it to the masses. In recent years, popular TV shows like Dancing with the Stars and So You Think You Can Dance have reignited interest in dances like the fox-trot, waltz, and tango. Which of these dances once sparked outrage for its impropriety?
Back in the day
Though the union of Austria and Germany was forbidden by the Treaty of Saint-Germain in 1919, the Nazis annexed Austria in 1938. The German term Anschluss—"annexation"—is most frequently used in reference to this event. When the Nazis entered Austria to enforce the Anschluss, they encountered no military opposition and quickly took control. The US, USSR, and UK signed a declaration proclaiming the Anschluss null and void in 1943, yet Austria did not regain its sovereignty until what year?
Born on a day like today
German physicist Gustav Kirchhoff was a pioneering scientist who contributed to the fundamental understanding of electrical circuits, spectroscopy, and the emission of black-body radiation by heated objects. He formulated several eponymous laws related to electrical circuits and thermodynamic reactions. Kirchhoff and Robert Bunsen—of Bunsen burner fame—began a new era in astronomy when they applied spectrum analysis to the Sun. Which two chemical elements did they discover in the 1860s?