Submarines operate for weeks or months beneath the ocean surface, cut off from the satellite signals that guide nearly every other modern vehicle. GPS radio waves cannot penetrate seawater beyond a ...

China has quietly launched another advanced submarine, signaling the rapid expansion of a naval ...

Chinese scientists have developed a crystal that produces ultraviolet light at a record 145.2 nanometers — meeting a key ...

Beneath the frozen expanse of the Arctic Ocean lies one of the world’s most challenging and strategically vital frontiers.