Remember how you read those issues of Silver Surfer from the ’60s and reflected long and hard about the possibility of pacifism when all an intergalactic traveler encounters was warlike aliens? The mad scientists at Darpa want you to put those musings to work on its most cosmic project yet.

Darpa recently launched a program called the 100 Year Starship, which is exactly what it sounds like: an effort to achieve interstellar flight by the year 2111. This is Darpa, so they’re dead serious. They also recognize that 2011-era technology probably isn’t good enough to forecast the state of the art ove...