"They ask in what medium do you mean?"
"How fast does light travel? In air? In glass? The speed of light is as variable as that of sound. If I can alter the nature of space, so as to make the velocity of light greater, can I not then go faster than in normal space?"
"They say that this is true," Torlos said, after more conversation with the men at the table, "but they say that space is unalterable, since it is emptiness."
"Ask them if they know of the curvature of space." Arcot was becoming worried for fear his explanation would be unintelligible; unless they knew his terms, he could not explain, and it would take a long time to teach them.
"They say," Torlos thought, "that I have misunderstood you. They say space could not possibly be curved, for space is emptiness, and how could empty nothingness be curved."
Arcot turned to Morey and shrugged his shoulders. "I give up, Morey; it's a bad case. If they insist that space is nothing, and can't be curved, I can't go any further."
"If they don't know of the curvature of space," said Morey, "ask them how they learned that the velocity of light is the limiting velocity of a moving body."
Torlos translated and the scientists gave their reply. "They say that you do not know more of space than they, for they know that the speed of light is ultimate. They have tested this with spaceships at high speeds and with experiments with the smallest particles of electricity."
The scientists were looking at Arcot now in protest; they felt he was trying to foist something off on them.
Arcot, too, was becoming exasperated. "Well, if they insist that we couldn't have come from another star, where do they think I come from? They have explored this system and found no such people as we, so I must have come from another star. How? If they won't accept my explanations, let them think up a theory of their own to explain the facts!" He paused for Torlos to translate, then went on. "They say I don't know any more than they do. Tell them to watch this."