It was a demographically explosive situation. Naturally emigration to Mars was often seen by Terran government planners as one solution to the problem. Even with its new ocean, Mars still had almost as much land area as Earth, and hardly any people. The really populous nations, Amy told the group, were already sending up as many people as they could. Often the emigrants were members of ethnic or religious minorities who were dissatified with their lack of autonomy in their home countries, and so were happy to leave. In India the elevator cars of the cable that touched down at Suvadiva Atoll, south of the Maldives, were constantly at capacity, full of emigrants all day every day, a stream of Sikhs and Kashmiris and Muslims and also Hindus, ascending into space and moving to Mars. There were Zulus from South Africa. Palestinians from Israel. Kurds from Turkey. Native Americans from the United States. “In that sense,” Amy said, “Mars is becoming the new America.”

“And like the old America,” a woman named Elizabeth added, “there’s a native population already there to be impacted. Think about the numbers for a while. If every day the cars of all the space elevators on Earth are full, then that’s a hundred people per car, therefore twenty-four hundred per day per elevator taking off, and a different twenty-four hundred leaving the cars at the top of each elevator, and transferring into shuttles. There are ten elevators, so that’s twenty-four thousand people a day. Therefore eight million seven hundred and sixty thousand people every year.”

“Call it ten million a year,” Amy said. “That’s a lot, but at that rate it will still take a century to transfer just one of Earth’s sixteen billions to Mars. Which won’t make any difference here to speak of. So it doesn’t really make sense! No major relocation is possible. We can never move a significant fraction of the Terran population to Mars. We have to keep our attention on solving Earth’s problems at home. Mars’s presence can only help as a kind of psychological vent. In essence, we’re on our own.”

William Fort said, “It doesn’t have to make sense.”

“That’s right,” said Elizabeth. “Lots of Terran governments are trying it, whether it makes sense or not. China, India, Indonesia, Brazil— they’re all going for it, and if they keep emigration at the system’s capacity, Mars’s population will double in about two years. So nothing changes on Earth, but Mars is totally inundated.”

One of the Immortals noted that an emigration surge of a similar scale had helped to cause the first Martian revolution.

“What about the Earth— Mars treaty,” someone else asked. “I thought it specifically forbade such overwhelming influxes.”