Shield is an old novel by Paul Anderson. It is not one of his best known works but it stuck with me anyway. It was written in the early sixties so a lot of the tech is dated (no internet for example) but it is still good.
Personally I find it interesting to read books written that long ago by masters of science fiction. All science fiction will be dated at some point after all, even mine will be some day. A book should be good even after this happens.
The book is about a naive astronaut that returns from mars. His was far from the first expedition, but it was the first that had the goal of pooling scientific and engineering knowledge. While the Martians were not much more advanced then us, they did go along paths we did not. Because of this the main character was able to create what he called a Shield. It was a device that projected a pill shaped bubble around the user that would stop everything but visible light (by design for obvious reasons) and relativistic particles (which it did not have the power to stop, but a larger unit could).
The main character thought that upon return to earth he would become a minor celebrity and the plans for the shield would be made public, as it said in the mission statement for his trip. Instead agents were sent to take the shield and to kill him. He ended up running because everyone, from the the US government to other governments and even crime bosses wanted the Shield.
The book has an interesting political landscape that plays into the book, but the really interesting thing to me is the idea of what would happen when a truly transformative technology is introduced.
The prototype shield is pill shaped with the user in a harness in the middle. This means that there are a lot of limitations in it’s use. However there was no reason it could not be shrunk down to the size of a pager, and made to cover your skin. Or made larger to cover cities and shield from even a nuke strike.
Stories like this are why I love science fiction.