Stunning Drone Footage From Beneath The Ice Of Antarctica

Scientists use a range of techniques—from satellite observations to drilling holes—to measure sea ice thickness. Usually, such efforts look down at the sea floor. But, by equipping an underwater drone with upward-looking sonar, researchers were able to create the first high-resolution 3D maps of Antarctic sea ice. » 11/25/14 2:40pm Tuesday 2:40pm

A Map Of The U.S., If There Had Never Been A Mexican-American War

In 1846, President James Polk, driven by a belief in Manifest Destiny, waged a war to seize land from Mexico and expand the nation's boundary from Texas to California. But events could have plausibly gone very differently, resulting in a map of the U.S. that would be significantly unlike the one we have today. » 7/30/14 7:40am 7/30/14 7:40am