The Man Who Made Time Travel

At sea, captains need to know their ships' location at all times or risk crashing into unseen dangers. Since people first took to the seas, the stars have been useful for measuring latitude-or position relative to north and south. But up until the 18th century, there was no accurate way to measure longitude-or position relative to east and west. Countless seamen were lost because they didn't know they had sailed into dangerous waters. To encourage the invention of an accurate method for mea...