Not all cows get to spend their days with soft green grass under hoof. For many, the picture isn't so pretty, according to the book Farmageddon. Justin Sullivan/Getty Images hide caption

itoggle caption Justin Sullivan/Getty Images

All of our scientific tools have limits. These limits ensure that we will never see the whole picture. We can never have complete knowledge of the universe. Above, the ESO's APEX radio telescope probes the heavens from its lonely perch on Chile's Chajnantor plateau. Gordon Gillet/ESO hide caption

itoggle caption Gordon Gillet/ESO

NFL Commissioner Roger Goodell at a press conference in May. Goodell's handling of concerns about concussions and controversies surrounding players has led commentator Frank Deford to wonder whether Goodell is up to the job. David Goldman/AP hide caption

itoggle caption David Goldman/AP

The Planters Nutmobile, seen here taking a starring turn at the Macy's Thanksgiving Day Parade, is hitting the road for a yearlong trip across the U.S. Peter Roan/Flickr hide caption

itoggle caption Peter Roan/Flickr

Jeff Koons poses in front of one of his sculptures during a media preview of "Jeff Koons: A Retrospective" at the Whitney Museum of American Art on June 24, 2014. Timothy A. Clary/AFP/Getty Images hide caption

itoggle caption Timothy A. Clary/AFP/Getty Images

Twelve-year-old Hayley Lindsay spent almost a month working with her dad on this Toothless the Dragon costume. There are sawn-off crutches in the front legs so she can comfortably walk on all fours. Petra Mayer hide caption

itoggle caption Petra Mayer