Comment Re:Scale smaller than the wavelength? (Score 1) 110
I'm not sure whether I understand the principles correctly, but if you can conjure up something that deflects seismic waves, you wouldn't need to drill holes under the entire city. All you'd need is a ring of deflectors around the city large enough to deflect a decent earthquake. The city would then only be unprotected in the unlikely event the epicenter is directly beneath the city.
Even if that is, for some reason, impossible, underground work is required in most cities on a regular basis anyway. One could drill the necessary holes when the sewers are upgraded, new utility lines are being laid etc. Sure, that would mean at least several decades before completion for most areas, but most nation-scale infrastructure projects take that much time anyway.