I am an aerospace engineer, with 134 publications to date.
I am a physicist, with 35 publications to date.
I am an inventor, with 28 patents to date.
I am a popular science writer, with 61 articles to date.
I am a science fiction writer, with 11 novels and 21 short stories published to date.
I have been a research department manager directing more than 50 scientists and engineers at one time.
I pioneered the field of gravitational engineering, and invented the gravitational mass detector.
I pioneered the fields of smart structures, of ultra-cold neutrons, of antimatter propulsion, of space tethers, of rocketless propulsion.
I was the first to figure out a way to go to the stars using laser-pushed light sails.
I was the first to invent a method for levitating spacecraft without its being in orbit.
The space tethers, which I invented and pioneered, will revolutionize space travel within the solar system.
Many of the fields in which I have done pioneering work are now being advanced by other people and other technologies. My philosophy as a scientist has been to work on problems that other people consider impossible. I chose that philosophy as a very young man, because if you make any progress at all on that problem, it is still an advance. When I felt I had launched a new technology, I wanted to move on to something new, different, and more difficult.
Heinlein also "invented" the cell phone as far back as 1948. It was pretty much a throw away scene involving two young cadets who had just met while traveling to be inprocessed at the Space Patrol Academy. One's parents call him while the two are talking, and the other says he fooled his parents by packing his phone in his suitcase so that they wouldn't be able to bug him.