Pick of the paperbacks; Disturbing the Universe, by Freeman Dyson. New York: Harper/Colophon books. $4 .95.

This book has to do with heroes -- the men and women who get up each morning, then go off to work to build nuclear reactors, experiment with recombinant DNA, and probe the universe for infrared sources of intelligent life.

Author Freeman Dyson is the main hero, despite his disclaimers. A distinguished physicist, mathematician, and astronomer, he not only discovered the theory of quantum electrodynamics; he can explain it in two-syllable words. Because Dyson loves his work, he can't help sharing it, and he constantly shows us the bits of insight and dreams he has collected over the past 50 years. He puts together sound how-to's for world disarmament and foresees a day of asteroid colonization and solar sa ilboats.