La violencia es el último recurso del incompetente - Isaac Asimov

Well, besides, I've arranged with the computer that anyone who doesn't look and sound like one of us will be killed if he — or she — tries to board the ship. I've taken the liberty of explaining that to the Port Commander. I told him very politely that I would love to turn off that particular facility out of deference to the reputation that the Sayshell City Spaceport holds for absolute integrity and security — throughout the Galaxy, I said — but the ship is a new model and I didn't know how to turn it off.
"He didn't believe that, surely."
"Of course not! But he had to pretend he did, as otherwise he would have had no choice but to be insulted. And since there would be nothing he could do about that, being insulted would only lead to humiliation. And since he didn't want that, the simplest path to follow was to believe what I said."
"And that's another example of how people are?"
"Yes. You'll get used to this."

First Speaker, the Seldon Plan is meaningless!

Pions are the mediating particles of the strong nuclear interaction. The intensity of the interaction depends on the mass of the pions and that mass can, under certain specialized conditions, be altered. The Lunar physicists have developed an instrument they call the Pionizer, which can be made to do jut such a thing. Once the pion's mass is decreased, or increased for that matter, it is, effectively, part of another Universe; it becomes a gateway, a crossing point.