"Radio linked the colonies of Sol, and after Neosol was colonized, radio linked its spread-out colonists.
"Forty years ago, Carrington discovered the Z-wave, an outgrowth of the superdrive. Then the instantaneous Z-wave replaced the slow radio transmissions that required teletype and code communications, and voice to voice contacts prevailed throughout the solar system, and throughout the system of Neosol.
"But the Z-wave did not cross the gulf of interstellar space, and years of experimentation followed, all of which failed. Then, twenty years ago, Chadwick Haedaecker suggested the theory now known as Haedaecker's Theory, which tended to show that the Z-wave propagated because of the fields of force generated in the central cores of stars. Since that date, only desultory attempts have been made to test the Z-wave in deep space. Experimentation had stopped, for all practical purposes. About the only people who have given the matter much thought are students of theory, and a couple of hardy souls like myself, who—I have been accused and of which I must admit—hoped to become rich and famous by making some extraordinary discovery.
"I will now advance the idea that I hope will be eventually known as Grayson's Principle.
"The basis of Grayson's Principle is that the Z-wave will not propagate between points that have not previously been linked by electromagnetic waves!"
This caused a storm in the auditorium. A showing of frantic hands flowered above the sea of faces and the hall broke into a growling murmur of muttering voices, discussing pro and con.
The chairman came forward and spoke to Paul: "Shall I call order, or would you prefer to have a mid-lecture discussion?"
Paul smiled nervously. "I was prepared for this," he said. "The rest of this will run better if we get this one point settled. It will be too long from now to the end of my lecture to make these men hold their questions."
"Good!" smiled Thorndyke. He rapped for order. "Gentlemen," he said, speaking over the incomplete attention, "Mister Grayson has just made a rather shocking statement, which is cause for controversy. He has suggested himself that a mid-lecture period of questions will hasten our understanding of his theory."
There was a burst of applause and the flowering of hands went up again.