On the technological horizon

Abstract

The early years of the space programme saw the origination of the interstellar ramjet. During the heady 1960s and 1970s, this approach seemed more than capable of permitting human exploration and colonsation of nearby solar systems. In fact, the entire Universe might open up to craft that followed the fictional track of Poul Anderson’s Leonora Christine. More recently, the original ramjet concept has appeared less feasible, and we may have to content ourselves with its less capable derivatives. But regardless of our current opinion regarding its ultimate feasibility, the ramjet concept is too exciting to be abandoned. It may still lead to relativistic interstellar travel.

It was a planet-sized shell of incandescence, where atoms were seized by its outermost force fringes and excited into thermal, fluorescent synchrotron radiation. And it came barely behind the wave front which announced its march. But the ship’s luminosity was soon lost across light years. Her passage crawled through abysses which seemingly had no end.

Poul Anderson, Tau Zero (1970)