And there he came to a halt. A trip to the moon took a mere ten hours; even a journey to Pluto, while it required four years, was conceivable. Conceivable and possible, as three growing cities gave testimony. But the stars were another problem altogether. The nearest was almost five light-years from Earth, an inconceivable distance even for this technically oriented century. Not only would the trip require half a dozen long-lived generations, but the ship would need an enormous amount of room for oxygen-giving plants, making the venture both financially and physically unfeasible. So Man looked elsewhere for a solution. The concept of hyperspace was tackled by every scientific mind in the Solar System for more than a century; the sole conclusion, reached countless times in countless experiments, was that hyperspace was a myth. And then, in the early years of the twenty-seventh century, a young Tritonian scientist devised a theory for an engine that would propel a ship at a faster-than-light speed. The scientific community scoffed at him, citing the long-standing theories that made a Tachyon Drive impossible; but the Solar Government, in overpopulated desperation, funded his project. Within two years the ship was complete. It was taken out into space some 75 million miles beyond Pluto and set into motion. It disappeared immediately, and neither ship nor pilot were ever seen again. However, the total transmutation of mass into energy and subsequent explosion predicted by the men of science was also undetected, and more ships were built around the faster-than-light principle. As Aristotle's earth, air, fire, and water had kept Man from discovering the true nature of atoms and molecules for an extra thousand years, so had Einstein kept him from the stars for half a millennium. But no longer!

There were immense problems at first.