 What is not a theme explored in this story?
The Sense of Wonder By MILTON LESSER Illustrated by HARRY ROSENBAUM Extensive research did not uncover any evidence that the U.S. copyright on this publication was renewed.] When nobody aboard ship remembers where it's going, how can they tell when it has arrived? But ever since the engines somewhere in the rear of the world had changed their tone, from the steady whining Rikud had heard all twenty-five years of his life, to the sullen roar that came to his ears now, the feelings had grown. The stars—it was a meaningless concept to Rikud, but that was what everyone called the bright pinpoints of light on the black backdrop in the viewport—were not apparent in the speckled profusion Rikud had always known. Instead, there was more of the blackness, and one very bright star set apart by itself in the middle of the viewport. But it came again, and each time it left him with a feeling he could not explain. Rikud knew that something which he could not explain had entered the elder man's head for a moment, but it had departed almost before Chuls knew of its existence. But something soft had cushioned the impact—something which had come into being just for the moment and then abruptly passed into non-being again, something which was as impalpable as air. There had been a revolt—again a term without any real meaning, a term that could have no reality outside of the reading machine—and the elders were overthrown. The people had decided that they did not know where they were going, or why, and that it was unfair that the elders alone had this authority. They were born and they lived and they died as the elders directed, like little cogs in a great machine. Much of this Rikud could not understand, but he knew enough to realize that the reading machine had sided with the people against the elders, and it said the people had won. Rikud often thought of his own death, still seventy-five years in the future, not without a sense of alarm. True, this was the only case of its kind, the exception to the rule, but it proved the world was not perfect. "Yes?" Almost no one read any more, and the library was heavy with the smell of dust. You can find several of them under 'astronomy,' with a cross-reference under 'stars.' "Astronomy says some stars are variable," Crifer offered, but Rikud knew his lame-footed companion understood the word no better than he did.
 Equality must be realized.
 Change is necessary and inevitable for survival.  Fear is a powerful motivator.  Perception can often be all-encompassing.  Equality must be realized.