“Then all the controls would have to be automatic,” I said. I told him that I had heard about plans for avoiding meteorites. “Electronic controls would be faster than thought.” “That’s probably the answer,” he agreed. “Of course, at a hundred miles a second it might not be too serious. But if they ever get up to speeds like a thousand miles a second, that mental lag could make an enormous difference, whether it was a meteorite heading toward you or a matter of navigation.” One of the problems he mentioned was the lack of gravity. I had already learned about this. Once away from the earth’s pull, objects in the space ship would have no weight. The slightest push could send crewmen floating around the sealed compartment. “Suppose you spilled a cup of coffee,” said the flight surgeon. “What would happen?” I said I hadn’t thought it out. “The Randolph Field lab can tell you,” he said. “The coffee would stay right there in the air. So would the cup, if you let go of it. But there’s a more serious angle—your breath.” “You’d have artificial air,” I began. “Yes, they’ve already worked that out. But what about the breath you exhale? It contains carbon dioxide, and if you let it stay right there in front of your face you’d be sucking it back into your lungs. After a while, it would asphyxiate you. So the air has to be kept in motion, and besides that the ventilating system has to remove the carbon dioxide.” “What about eating?” I asked. “Swallowing is partly gravity, isn’t it?” He nodded. “Same as drinking, though the throat muscles help force the food down. I don’t know the answer to that. In fact, everything about the human body presents a problem. Take the blood circulation. The amount of energy required to pump blood through the veins would be almost negligible. What would that do to your heart?” “I couldn’t even guess,” I said. “Well, that’s all the Aero-Medical lab can do—guess at it. They’ve been trying to work out some way of duplicating the effect of zero gravity, but there’s just no answer. If you could build a machine to neutralize gravity, you could get all the answers, except to the ‘dead distance’ question. “For instance, there’s the matter of whether the human body would even function without gravity. All down through the stages of evolution, man’s organs have been used to that downward pull. Take away gravity, and your whole body might stop working. Some of the Aero-Medical men I’ve talked with don’t believe that, but they admit that long trips outside of gravity might have odd effects.