On April 2, 1936, when the 22-year-old son of a sharecropper entered the Olympic Stadium in Berlin, he was, he later remembered, barely able to control his anger. “I was angry because of the insults that Hitler and the other German leaders had hurled at me and my Negro teammates on the Olympic squad.” The young athlete would channel his raw emotions into some of the most remarkable achievements in the history of athletics, winning four gold medals.

Are you safe aboard a modern cruise ship? Twenty million passengers embark on cruises each year, vacationing in deluxe “floating cities” that offer everything from swimming pools to shopping malls to ice skating rinks. And the ships just keep getting bigger: The average cruise ship has doubled in size in just the last 10 years. Some engineers fear that these towering behemoths are dangerously unstable, and the recent tragedy of the Costa Concordia has raised new questions about their safety.