[ghost8772]

I'm thinking Heinlein used turning points in any number of colonies deciding on a trial separation around the world. the use of The United States Declaration of Independence, though was conscious, something HE respected. the dropping of rocks on the earth was basically his way of pointing out that a breakaway group is going to have little or no advanced weaponry, and must make do. rocks and a gravity well work wonders in that situation. Heinlein makes/made many technical errors, but since he wrote for mainline readers, not technical journals, he, and a number of casual readers were convinced that to hurl items magnetically, they had to have ferrous compositions involved. (another waittasecond is if you you press on a gyroscope along all three axes at once, it will wither dislodge from its gimbals, and fall, or it will have a higher friction coefficient and try to stop. it will not disappear.)