Across decades of Cold War ambition and quiet scientific persistence, humanity has wrestled with one of its most humbling confrontations: the sheer indifference of cosmic distance. From fission reactors strapped to rockets in the Nevada desert to the audacious vision of a spacecraft surfing nuclear shockwaves, engineers and physicists have reached toward the stars only to find that even our most radical ideas leave us centuries short of arrival. The nearest star remains 4.25 light-years away — a number that absorbs every shortcut we have yet devised — and the question of whether we will ever c