Reaching for the stars, across 4.37 light-years

-- Dennis Overbye Can you fly an iPhone to the stars? In an attempt to leapfrog the planets and vault into the interstellar age, a bevy of scientists and other luminaries from Silicon Valley and beyond, led by Yuri Milner, a Russian philanthropist and Internet entrepreneur, announced a plan on Tuesday to send a fleet of robot spacecraft no bigger than iPhones to Alpha Centauri, the nearest star system, 4.37 light-years away. If it all worked out — a cosmically big "if" that would occur decades and perhaps $10 billion from now — a rocket would deliver a "mother ship" carrying a thousand or so small probes to space. Once in orbit, the probes would unfold thin sails and then, propelled by...