In Heinlein's world fossil fuels became so rare and valuable (sound familiar) that the US government decided that the military should have priority access to it. Fuel prices became so expensive that a new method of mass transportation was created, he re-imagined roadways to be a series of conveyor belts each one going a bit faster than its neighbor, up to speeds of 100 MPH. These roadways were powered by solar panels; very well imagined considering this story was published in 1940.
At the time the leading thinker on photovoltaic energy was Albert Einstein, who won the Nobel Prize in 1921 for his work in the area. Look HERE for more information on that.
It takes a lot of work to keep the roadways rolling, during this story a revolt unfolds from the trade unionists that maintain the infrastructure.
This has all the right ingredients to make a fine modern day science fiction, action movie. While reading it I kept thinking this story had the same look and feel of the movie I Robot - a gleaming city on top and a gritty world underneath it all, keeping it all running.
Good story even if the end of it is a bit clunky. I'm sure it could be improved in the movie. (Just kidding)
Information or Robert A Heinlein can be found HERE and HERE
|Robert A Heinlein|