There were. Maybe still are moderated usenet groups. Nothing gets posted unless approved by a moderator.

http://en.wikipedia.org/wiki/Magnetohydrodynamic_drive "The film adaptation of The Hunt for Red October popularized the magnetohydrodynamic drive as a "caterpillar drive" for submarines, an undetectable "silent drive" intended to achieve stealth in submarine warfare. In reality, the current traveling through the water would create gases and noise, and the magnetic fields would induce a detectable magnetic signature." The magnetic field doesn't come from the hull.

"Red October", the story of the largest magnetic anomaly in the ocean, that for some reason was undetectable by the US Navy, because. . . Well damnit because I said so. Reading Clancy made you stupider.

All the science you need to know is in the Bible. Or so the Republicans seem to be telling us.