X-link to the DRM-free thread for the new Humble Bundle:
Humble Book Bundle Science Fiction by Real Scientists presented by textbook publisher Springer contains hard sfnal speculative fiction titles (of the sort that
Nature sometimes publishes) by (mostly non-genre-writer, though Dr. Brad Aiken does have an
ISFDB entry) academic scientists, with explanatory afterwords, and also some non-fiction about the science behind science fiction.