US commandos parachuted into N. Korea

[jberryhill]

30. It's basic E&M

On fields & waves theory, they're fine. Making sure there is enough reflective density on the top of a deep tunnel to mask the hole underneath is not hard and doesn't require advanced materials.

It's amazing how creative smart people get (and they have enough of a cadre of smart folks) when circumstances dictate.

The tuned acoustic resonators that the North Vietnamese had guys stand inside in order to do long range air raid detection, for example, were pretty cool. Cuban farm yield techniques is another.

We've applied the same techniques to tunnels under the US-Mexico border, and they still manage to dig them and use them from time to time.

If we are talking about underground complexes tucked away anywhere in the DPRK, that's more territory than you are going to cover with ground penetrating radar. You have to have some pretty good idea where you are looking for whatever it is you are looking for.

I hate to paraphrase Rumsfeld, of all people, but we know what we know and we know some things that we don't know, but the things we don't know that we don't know are the buggers.

On another note entirely, did you catch the "traffic accident" rash that has killed off just about any DPRK official who has been engaged in any talks with the South? That's a great Stalinesque move. If you don't know who might have been leaking what, then take the pre-emptive course of killing anyone who had the opportunity, whether they leaked or not. That's pretty hardcore. Order half of your most presumed loyal followers to kill the other half, and it's a pretty sure bet that the ones left are not going to step out of line.