Tennis has a fuzzy yellow problem most players don't think about when they open can after can of fresh balls, or when umpires at U.S. Open matches make their frequent requests for "new balls please." ...

Whipping his racquet through the air like a cesta in jai alai, Rafael Nadal produces such tremendous topspin that the ball sometimes seems to catapult off the court, creating a shot as challenging to ...

Earthquakes cannot be forecast, but engineers can prepare for them. Seismic-isolation systems built into the bases of certain buildings in high-risk areas, such as San Francisco’s City Hall, use ...