Though "Doc" Smith's title was strictly honorary, he nonetheless brought a very scientific
outlook to his tales, and helped to birth science fiction
as we now know it with his writings in the early part of the 20th century.
Smith is best known for his Lensman series, as well as the four-book Skylark saga. Though his novels had a very pulp feel to them, and some of his predictions were laughable (such as advanced electronic computers with 8 whole K of memory), Smith wrote what could easily be considered hard science fiction for his day...many of his inventions like the inertialess drive were predicated on nullifying a particular law of physics to observe the consequences. Charles Sheffield's McAndrews Chronicles feels very much like a homage to this facet of Smith's work.