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Few mysteries seem beyond the soaring ambition of radio astronomers. In the past, most cosmographical theories were concocted by mathematicians sitting in quiet rooms and struggling with streams of abstractions. They were safe from experimental check because optical telescopes could not see far enough into the depths of the universe. But radio telescopes are keener-sighted. They have located radio-galaxies that seem to be 7 billion light-years away. And their eyesight is bound to improve.
Since radio waves travel at the same speed as light, when radio telescopes peer deep into space, they also look into the far-distant past. Galaxies 7 billion light-years away are studied on earth just as they were 7 billion years ago, before the earth was born. Little is known thus far about these ancient galaxies that have been fossilized by time and distance. Perhaps when more is known, man will get some idea of what the young universe was like and when it was born. Or, perhaps, when the radio astronomers have improved their skill, they will prove that the universe is eternal—that it was never young, and will never grow old.