Finally he understood and explained: "This ship is to go into an orbit to nullify gravity. Science doesn't have to depend on trial and error. They can calculate a thing mathematically and predict the results. They worked out your idea that gravity is what breaks down the cells. The answer is that the body will not age so long as it replaces its cells and gets rid of its old ones. To free the body of gravity will slow down the cellular breakdown. In ten years you won't age as much as you would in one in a field of gravity. Is it clear?" "Will that postpone the change of life?" "Medical science is certain that it will. It devolves upon aging." "Does that mean that I'll--" "It does, Sue. It means that about fifty years from now when the sperm revives in men, you women will have children again." "But Al, we'll be--" "No, Sue. We'll feel and look about as we ordinarily would in our twenties. And thousands, millions of ships, will soon be released to be converted. A whole populace will live in ships--at least until children begin being born." "Will we--" "Yes, Sue. We'll have a few ounces of weight in the orbit. Our cells will more than replace themselves. We'll adjust to it, carry along hydroponic plants and everything we need. We'll be strong and vigorous, with nothing much to do but study, work out new things in the arts and sciences, and--" "And what, Al?" "Make love." "Oh!" she said. "Deep inside me I've always believed in that bright future. I was trying to remember that each tomorrow would bring it closer." "The big job is almost done, Sue. Let's keep on remembering tomorrow." "Hold me close, Al."