Remember there are only three types of explosives known: chemical, mechanical and nuclear... detonators for each are not very large, and in the covert world easily concealed to look like some other benign object.. wristwatch, ballpoint pen, telephone keypad, etc. And again I'd like to caution readers from drawing the conclusion that the TT and WTC7 were "controlled demolitions"... they were "simply" demolitions, no matter which causal theory one subscribes to.
I can think of at least two ways to bring down tall steel buildings remotely without using explosives at all, and which would leave no trace evidence... it's just so much more far-fetched that oscillators or lasers were used that it's not worth seriously raising these as talking points.
I can think of at least two ways to bring down tall steel buildings remotely without using explosives at all, and which would leave no trace evidence... it's just so much more far-fetched that oscillators or lasers were used that it's not worth seriously raising these as talking points.