The Invincible was nearing Mars, heading for Earth, which was still a greenish sphere far to one side of the flaming Sun.
Russ watched the little green globe, thinking.
Earth was home. To him it always would be home. But that would be changed soon. Just a few more generations, and, to millions upon millions of human beings, Earth no longer would be home.
With the new material energy engines, life on every planet would be possible now, even easy. The cost of manufacture, mining, shipping across the vast distances between the planets would be only a fraction of what it had been when man had been forced to rely upon the unwieldy, expensive accumulator system of supplying life-giving power.
Now Mars would have power of her own. Even Pluto could generate her own. And power was ... well, it was power. The power to live, the power to work, to establish and maintain commerce, to adjust gravity to Earth standard or to any standard. The power to remake and reshape and rebuild planetary conditions to suit man exactly.
Earthmen and Earthwomen would be moving out en masse now to the new and virgin fields of endeavor—to the farms of Venus, to the manufacturing centers that were springing up on Mars, to the mines of the Jovian worlds, to the great laboratory plants that would spring up on Titan and on Pluto and on the other colder worlds.
The migration of races had started long ago. In the Old Stone Age, the Cro-Magnon had swept out of nowhere to oust the Neanderthal. Centuries later the barbarians of the north, in another of those restless migrations, had overwhelmed and swept away the Roman Empire. And many centuries later, migration had turned from Europe to a new world across the sea, and fighting Americans had battled their way from east to west, conquering a continent.
And now another great migration was on—man was leaving the Earth, moving into space. He was leaving behind him the world that had reared and fostered him. He was striking out and out. First the planets would be overrun, and then man would leap from the planets to the stars!
For years after America had become a country, had built a tradition of her own, Europe was regarded by millions as the homeland. But as the years swept by, this had ceased to be and the Americas were a world unto themselves, owing nothing to Europe.