U.S. soldiers at Long Binh base in South Vietnam line up to give urine samples at a heroin detection center before departing for the United States. About 20 percent of soldiers said they were addicts, but most didn't continue drug use back home. AP hide caption

itoggle caption AP

A woman shouts slogans as she attends a pro-Palestinian rally July 25 in Berlin. About 1,200 pro-Palestinian demonstrators marched through Berlin amid high tensions over Israel's actions in Gaza, while some 700 protesters took part in two counter-demonstrations. Markus Schreiber/AP hide caption

itoggle caption Markus Schreiber/AP

In diverse workplaces and classrooms — such as this one at Connections Education in Baltimore — recent research suggests that adhering to standards of political correctness can actually boost, rather than inhibit, the generation of fresh ideas. Tom Dubanowich/PR Newswire hide caption

itoggle caption Tom Dubanowich/PR Newswire

This is a re-creation of a color plate from Interaction of Color, by Josef Albers. The two X's are are exactly the same — it's the different backgrounds that make them look like very different colors. Source: Josef Albers Interaction of Color hide caption

itoggle caption Source: Josef Albers Interaction of Color

A contentious piece of clothing: Members of the Iranian women's soccer team celebrate their win over Syria back in 2007. That year, the international soccer league FIFA banned the wearing of hijabs during games. The ban was lifted in July. Mohammad Abu Ghosh/AP hide caption

itoggle caption Mohammad Abu Ghosh/AP

Jude Law prepares for the looming pandemic in the 2011 movie Contagion. There are huge differences between viruses in movies and Ebola in real life. Warner Bros/The Kobal Collection hide caption

itoggle caption Warner Bros/The Kobal Collection