Two robotic legged squad support system (LS3) machines by the Defense Advanced Research Project Agency follow a technician during a demonstration at Joint Base Myer-Henderson Hall, Virginia, on September 10, 2012. (U.S. Marine Corps photo by Sgt. Mallory S. VanderSchans via The Atlantic)

A view of the construction site of the Chateau de Guedelon near Treigny in the Burgundy region of France, September 13, 2016. Blacksmiths, stonemasons and quarry men are hard at work in a Burgundy forest building a 13th-century-style castle using the most basic tools and materials, replicating the methods used hundreds of years ago to better understand them. (Photo by Jacky Naegelen/Reuters)

Construction of the cable road on Broadway in 1891. (Photo by New York Public Library)

Daniel Filip, Tech Lead Manager for Google Maps, carries the Trekker, a 15-camera device, while mapping the Inca citadel of Machu Picchu for Google Street View in Cuzco, Peru, August 11, 2015. (Photo by Pilar Olivares/Reuters)

If we asked you to think of your favorite cute animal, you might not immediately list a duck, but when you see this Reddit user and his pet duckling Peeps you may change your mind. Peeps is fuzzy, he’s lovable and he grew up in a beard (really). The man initially bought Peeps as an egg, thinking he was a chicken. He was wrong, but he didn’t care, it turned out to be one of the cutest friendships ever.

The Empire State Building towers over the Manhattan skyline as tourists gather on the observation deck of Rockefeller Center on February 13, 2012 in New York City. The owner of the Empire State Building, Malkin Holdings, plans to raise up to $1 billion in an initial public offering on the 102 story Manhattan landmark. (Photo by John Moore/Getty Images)

An image of the popular video game “Angry Birds” is displayed on an iPod Touch on March 18, 2011 in San Anselmo, California. The “Angry Birds” mobile device video game developer Rovio is begnning the process of seeking an initial public offering (IPO). (Photo Illustration by Justin Sullivan/Getty Images)

Just a week before Rio de Janeiro hosts South America's first Olympics, city residents expressed mixed feelings about the cost and security of the Games, while holding out hope they will bring joy to a nation facing economic and political crises. The conflicted thoughts mirror a recent survey by the Datafolha polling group showing that half of Brazilians were opposed to holding the Games, while 63 percent think the costs of hosting the event will outweigh benefits. (Photo by Pilar Olivares/Reuters)