Libyans flee on foot along the main road heading west, away from Sirte, on Tuesday. Sirte, cut off from the rest of the country, is the last major town controlled by forces loyal to toppled dictator Moammar Gadhafi. Gaia Anderson/AP hide caption

Mexican journalists march in a protest against violence directed against the media on Sept. 11, in Mexico City. Drug cartels, which have been responsible for many of the deaths, are now intimidating social media sites. Ronaldo Schemidt/AFP/Getty Images hide caption

Marchers demonstrate against the German labor reforms, known as Hartz IV. (November 5, 2005) Sean Gallup/Getty Images hide caption

Cattle and zebra share a meal in a pasture in Kenya. Ryan Lee Sensenig/Science hide caption

Justin Mudge walks through the muddy interior of his great uncle's gun shop, destroyed by flooding caused by Irene on Sept. 1 in Prattsville, N.Y. FEMA will run out of money to help disaster victims by early next week unless Congress acts. Monika Graff/Getty Images hide caption

SawStop, a table saw safety tool, senses an electrical current in skin and triggers a brake when a finger comes into contact with the blade. Courtesy of SawStop hide caption

A neutrino detector like this one, seen at Los Alamos National Laboratory in 1995, was used to collect data claiming that neutrinos can travel faster than the speed of light. Fred Rick/Time & Life Pictures/Getty Image hide caption