My husband is currently taking physics at Middle Tennessee State University (MTSU) and their first physics lab was to claculate pi by wrapping a piece of string around a pipe five times. Due to the extra length in the coil, they came out at about 3.3. So while Heinlein was being satirical, he wasn't far off the mark. My hubby is a Heinlein freak, I wonder if he thought of the seminal novel while doing the lab.