The above quadrilogy is called Queendom of Sol. In those books, the characters are immortal. Not just the main characters, but everyone in our solar system. All I can really say is that if immortality interests you, then you need to read these books. And the 'hard' science, well, it goes way beyond anything I've read in a Clarke, Niven, or Asimov novel.
In real life, McCarthy also holds a patent on wellstone, which is a substrate for artificial atoms. He wrote a nonfiction book titled Hacking Matter, which explains wellstone. He got the idea for wellstone from quantum dots.