"Hearst Magazines and Yahoo may earn commission or revenue on some items through the links below." A new paper suggests that time can actually flow forward and backward. Microscopic systems can ...

Engineering researchers have discovered that sand can actually flow uphill. A corresponding video shows what happens when torque and an attractive force is applied to each grain -- the grains flow ...

When we think of rivers, we think of water generally flowing, in a linear fashion, from high ground to the sea. Did you know there are some rivers on Earth that actually flow in reverse from their ...