Surface tension creates a glassy, smooth layer of water over U.S. swimmer Tyler Clary the instant before he surfaces as he competes in the backstroke. Surface tension arises from intermolecular forces between water molecules.
In 2007, the Department of Water Protection in Los Angeles detected high levels of bromate, a carcinogen that forms when bromide and chlorine react with sunlight, in Los Angeles's Ivanhoe Reservoir. Bromide is naturally present in groundwater and chlorine is used to kill bacteria, but sunlight is the final ingredient in the potentially harmful mix
What's significant about the latest find is that the rocks are the "first ever" discovered on the Red Planet to contain streambed gravels. The rocks were found by Curiosity last fall. Examining them over time, researchers actually were able to determine how deep and fast the water flowed at that location.
"At a minimum, the stream was flowing at a speed equivalent to a walking pace -- a meter, or three feet, per second -- and it was ankle-deep to hip-deep," Rebecca Williams of the P