pharos at gmail.com
Sun Jul 20 16:22:23 UTC 2014
On Sun, Jul 20, 2014 at 12:27 AM, David Lubkin wrote:
> Are there any credible technologies, either current or plausible future,
> that can stymie tunneling by wealthy, motivated opposition along ranges from
> (say) 10^2 to 10^6 meters --at least by anything less than a hypothetical
> shaped nuclear charge, MNT disassemblers, or the sort of large, expensive
> tunnel boring machine that is hard to obtain or conceal?
Ground penetrating radar as used by archaeologists? Can detect voids
up to 15 metres below the surface, depending on the soil structure.
Back in medieval times and WWI, listening devices were used to detect
the sounds of tunnelling.
More information about the extropy-chat