But when Keller's painstaking instructions for the building of gravity-field detectors reached Earth, these suspicions seemed less plausible. The United States passed on the instructions. The basic principle was so new that nobody could claim it, but it was so simple that many men felt a wholesome shame that they had not thought of it before. Nobody could question a natural law which was so obvious once it was stated. And the building of the device required next to no time at all. Within days then, where the asteroid had a single ten-foot instrument, the United States had a ten-foot, a thirty-foot and a sixty-foot gravity-field detector available to qualified researchers. The new instruments gave data such as no astronomer had ever hoped for before. The thirty-foot disk, tuned for short range, pictured every gravitational field in the solar system. A previously unguessed-at Saturnian moon, hidden in the outer ring, turned up. All the asteroids could be located at one instant. The mystery of the inadequate mass of Pluto was solved within hours of turning on the thirty-foot device. When the sixty-foot instrument went on, scaled to take in half a hundred light-years of space, the solar system was a dot on it. But four dark stars, one with planets, and twenty-odd planetary systems were mapped within a day. On that same day, though, a query went back to Keller. What, said the query, was the meaning of certain crawling, bright-red specks in mathematically exact relationship to each other, which were visibly in motion and much closer to Earth than Alpha Centaurus? Alpha Centaurus had always been considered the closest of all stars to Earth. Under magnification the bright-red sparks wove and interwove their paths as if about a common center of gravity. If such a thing were not impossible, it would be guessed that they were suns so close together as to revolve about one another within hours. Even more preposterously, they moved through space at a rate which was a multiple of the speed of light. Thirty light-speeds, of course, could not be. And the direction of their motion seemed to be directly toward the glowings which represented the solar system containing Earth. All this was plainly absurd. But what was the cause of this erroneous report from the new device? Keller wrote out very neatly, "_The instrument here shows the same phenomenon. Its appearance much farther away triggered the transmitter here to send the first signals to Earth. Data suggests red dots represent artificial gravity-fields strong enough to warp space and produce new spatial constants including higher speed for light, hence possible higher speed for spacecraft carrying artificial gravity generators. Request evaluation this possibility._"