Scientists have uncovered a surprising new way that giant embryonic cells divide—without relying on the classic “purse-string” ring long thought essential for splitting a cell in two. Studying ...

In 1869, John Wesley Powell was studying layers of rock in the Grand Canyon when he noticed an unconformity in the layers. Around a billion years were missing, and the problem turned out to be global.

If the dog slowed or stopped for a break, it could expect hot coals to be thrown into the wheel with it, Bondeson explained; the little guys were scolded and beaten, worked non-stop for hours on end; ...