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

Does she really think you're funny, or is she just being polite? Jon Feingersh/Getty/Getty Images/Blend Images RM hide caption

itoggle caption Jon Feingersh/Getty/Getty Images/Blend Images RM