"Similarly, a _receding_ luminary pulls its waves--and the pitch of its light is indicated by a 'red shift.' "Observation has taught us the tragic falsehood that everything in the universe is running away from all else. We have learned to believe in an 'expanding universe'. "But--" Once again Gary placed his finger upon the photographs--"study these margins! These fine lines are the spectrographs of the comet you have just seen. Do _they_ agree with our established theories?" Dr. Bryant stared. "But this is incredible, Gary! If the comet in your pictures were nearing our galaxy--as it undoubtedly was--it should at all times exhibit a violet shift. But, instead, it shows here a _red_ shift up to the moment of its departure from its normal course--and thereafter a violet shift!" And he looked at Lane, wide-eyed and wondering. Dr. Anjers also studied the younger scientist with respect. Asked the Eurasian, "And the conclusion you draw, my young friend?" "There is," said Gary seriously, "but one conclusion possible. Science has erred for almost three centuries. Our universe is _not_ expanding. All other galaxies are _not_ racing headlong from our own. The Greater Universe is steadfast and secure. It is only our little solar galaxy which moves. And we--_are contracting_!" CHAPTER II The Deadly Radiation Nora Powell was frankly out of her depth. It showed in her eyes, and in the petulant protrusion of her lower lip. She asked, cool gaze studying her new superior, "Would you be kind enough to explain that more fully, Dr. Lane?" Gary needed no urging. It was this theory which was responsible for his unusual curtness, for his irate explosion at the rocketdrome, for the preoccupation that had marked his return flight from Luna to Earth. He wanted most desperately to convince his superior, Dr. Bryant, and all his other associates, that this startling discovery was not lightly to be dismissed. Furthermore--and it surprised Gary Lane to find the desire within him--he wanted to prove to Nora Powell that he was not, in truth, the ogre she now believed him. That there had been an excuse for his rudeness. So he spoke, setting forth the arguments thought out during the flight from Earth's satellite. "You are all familiar," he said, "with the theory of the 'expanding' or 'bubble' universe. "We approach an understanding of this by thinking of our existence--our universe of three spatial dimensions with one temporal extension--as a sphere which is _all_ surface. "Not merely a hollow sphere, you understand. _Everything_--including empty space, solid matter and energy, is on the surface of this hypersphere. Thus our galaxy constitutes one point imbedded in the surface of the sphere ... the nearest star is another ... the farthest still another ... and so on with each of a billion galaxies.