An accurate simplification of our universe, but one couched in so sophisticated a phraseology that it may make more parents ponder than youngsters learn. Rather breezily, Mr. Lewellen provides many facts about the nearest star, possible climates etc. on other planets, Einstein's theory of relativity, and the still mysterious origin of the atom. But format and content, too simple to interest 9 to 11's. do not have the easy classifications and terminology the uninitiated need.