Stella: What do you think of weapons that use wavelengths of energy? Certainly we have tasers.
First (and just to be pendantic) it's a bit inaccurate to speak of "wavelengths of energy," since energy comes in many forms, and only a subset -- primarily electromagnetic radiation -- are measurable in wavelengths.
That aside, tasers are a singularly poor choice to cite in support for a DEW. Indeed, the limitations of the taser points out the difficulties in developing such a weapon. Tasers deliver an electroshock to the target, and only work when they are in direct contact with the skin. Even a small gap between the electrodes and the target renders the taser useless, since (and this is a critical point) air is a very poor conductor. Yes, large scale discharges (such as lightning) can traverse the air, but that takes vasts amounts of energy to do any large-scale damage of the sort witnessed on 9/11. So taser technology, no matter how vastly scaled up, could not have possibly taken down the WTC.
Do you think the only weapons we have of this nature are already 100% publicly known?
No doubt there's various classified work underway around particle beam and other "ray gun" technologies, perhaps remnant projects of the heyday of SDI. But that's not really the point. If a DEW weapon of the sort Dr. Wood hypothesize does exist -- and remember, it's up to her to prove it does, not I to prove it doesn't -- then if it were used on 9/11, it would have left copious amounts of incontrovertable evidence behind, evidence that would have been readily witnessed by literally millions. That last statement isn't based on speculation or opinion; it's simply basic science. No such evidence was observed -- none at all.
Do you think there is 0% chance of the existence of a DEW?
Its existence, possibly in some prototypical scale-model form? No, I can't say 0% chance. But if you re-phrased the question as "Do you think there is 0% chance
that a DEW was used on 9/11 to bring down the WTC?" then I'd say yep -- 0% is 100% right.