There are DEW in all ranges of the light spectrum, not just the visible.
And in
any range, the beam would have been spectacularly visible as it interacted with the smoke and debris from the building.
Moreover, as DEW exist and are deployed, your expert is woefully out of date.
I'm skeptical that any theoretical DEW with enough power to vaporize thousands of tons of steel could actually become airborne let alone be put into orbit.
jammonius has failed to answer my challenges from
post 135. In particular, I asked her exactly what directed-energy weapons are currently deployed, as she claimed, in orbit.
But
jammonius' appeal to the general notion of directed-energy weapons, without any evidence whatsoever for the existence of the skyscraper-vaporizing beam she keep alleging, or any understanding of the effects such a beam would and would
not have, can be addressed
quantitatively, despite her obviously incorrect claim
here that
Almost all so-called 'technical' discussions of DEW centering, for instance, on the "power requirement" are so assumption riddled as to be next to useless. The problem can be bounded.
Let's take a crude look at what it would take to vaporize about
one percent of the roughly 96,000 tons of steel in each of WTC 1 and 2.
For the sake of convenience, we'll use one metric ton (1000 kg), which is actually 1100 "short" tons. Again, it's a little over one percent of the steel in one of the buildings.
I'm also going to use the heat of vaporization for iron. I know this is just an approximation for that of steel, and I don't know whether it's high or low. But I'm sure it's good enough for an order-of-magnitude estimate.
Fe, Heat of vaporization: 349.60 kJ/mol
Fe, Atomic mass 55.847 => 1 mol Fe = 55.85g
=> Heat of vaporization = 349.60 kJ/(mol * 55.85 g/mol) = 6.26 kJ/g
Energy needed to vaporize that much iron = 6.26 kJ/g * 10
9g ~ 6.3*10
9 kJ = 1.7*10
6kWh.
But this power must be delivered over only about 10 seconds - let's make it 20 to be very generous:
Power required = 1.7*10
9Wh / (20s / 3600s/h) = 310*10
9W (310 gigawatts).
jammonius has repeatedly offered as support for her claim a picture of the Air Force's Airborne Laser (ABL), which is being integrated into a converted 747. The
Missile Defense Agency's fact sheet notes that the ABL, a
megawatt system, has delivered its energy over a ten-second period, which is about the right length of time - but only in a lab test. Not in flight. So
jammonius' example isn't even
operational.
The operational ABL is supposed to be able to take up to 40 shots, up to 5 seconds each, with its chemical-oxygen-iodine laser (COIL) (which itself weighs something on the order of 18,000 kg). I don't have the output power (I wouldn't be surprised if it's classified), but let's generously say it's 10 MW. Thus, the ABL that
jammonius is so fond of showing as support for her claim has a beam power
five orders of magnitude too small for our limited scenario.
But power is only one of the problems. The total energy needed, even in the very limited, purely theoretical (100% efficiency) scenario, also shows how laughably disconnected
jammonius' scenario is from reality. Using our generous 10MW beam power guess for ABL, it can deliver 40*5s*10MW = 2000MWs, or 2*10
9Ws ~560,000 Wh ~ 560 kWh.
Thus, the energy available to the ABL system for one flight is, very roughly,
three-tenths of one percent of what is necessary to
theoretically vaporize
roughly one percent of the steel in
one of the Towers. And it hasn't even flown yet.
And that doesn't take into account atmospheric attenuation, or attenuation from all the smoke and dust from the towers - which, as I mentioned earlier, would have lit up
blindingly from that kind of beam hitting it. Or the fact that no orbital track will take an alleged tower-zapping satellite back "in range" an hour later. (If you speculate a geosynchronous satellite, your atmospheric attenuation and beam-spreading issues become even
more ludicrous.) Or the other issues associated with the construction, launch, operation, efficiency, and visibility of such a system. Or the problem of generating and using the power needed. (See
R. Mackey's excellent post exploring a range of such topics.) Let alone the fact that there is no evidence whatsoever for its existence, or that the observed reality doesn't match the claimed mechanism, or that
jammonius can't even describe that the "directed energy"
is. The whole DEW-zapping-WTC scenario is nothing more than a particularly delusional handwave.