Charles Sheffield, a mathematician and physicist, is a past president of both the American Astronautical Society and the Science Fiction Writers of America, and the chief scientist of the Earth Satellite Corporation. He has published over a hundred technical papers and monographs on such subjects as nuclear physics, gravitational field analysis, and general relativity, and an equally large body of popular science articles for the layman. He serves as a science reviewer for several prominent publications.

In science fiction, Dr. Sheffield has received the coveted Nebula and Hugo Awards, as well as the John W. Campbell Memorial Award for his novel for Baen, Brother to Dragons. His other SF novels for Baen include The Mind Pool and its sequel, The Spheres of Heaven, Between the Strokes of Night, Convergent Series, and Transvergence. He is also the author for Baen of Borderlands of Science: How to Think Like a Scientist and Write Science Fiction, which is both a nonfiction survey of current scientific frontiers and an explanation of how a science fiction writer can write SF using bona fide scientific knowledge. Which is just the sort of SF that Dr. Sheffield has been writing for some time now, to the resounding acclaim of readers and critics alike.