Good so far, but there’s a couple things I think we still need to make the debunking complete. First of all, I should add a couple more details of this particular conspiracy theory. One, they contended that the planes weren’t actually the commercial flights we were told they were, and were probably military aircraft. They offered testimony from eyewitnesses who said they didn’t look like commercial airlines; one person said the plane he saw had no windows. So to be fair to the conspiracy nuts advancing the theory, they weren’t suggesting that a missile was somehow strapped to a commerical flight, but that the planes that struck the towers were entirely different planes altogether.

Of course, none of that is particularly convincing, because eyewitnesses frequently just plain rememer details wrong. You can hear all kinds of different stories from people who witnessed the same event. And of course it raises the question of what did happen to those commercial flights, if they didn’t crash into the towers, because it seems pretty clear that those flights did take off, and didn’t return.

But the thing that does, on first blush, seem fairly convincing, is that flash of light. CurtC, those pictures you linked to look like what they were talking about. The video quality is just too poor, IMO - you really can’t tell if the plane has struck the building yet when the flash happens, so my instinct would be to assume it had already struck the building. But the quesion now is, does “metal hitting metal at high speed” cause a flash like that? It’s a pretty sizable flash; I would almost call it an explosion. I can see how metal hitting metal would make a lot of sparks, but would it make a big fireball like that? What is fairly clear is that the fuel tank hadn’t hit yet.

GorillaMan and others, I’m curious if you still think it was a fuel-tank explosion after looking at the pictures? The fuel tank isn’t located that far forward in the fuselage, is it? I do remember that in other plane crashes, witnesses have mistaken a fuel explosion for a missile strike, but I’m thinking that isn’t the case here. I also wonder if those of you who said the fuel wouldn’t need to be ignited, can clarify that. It’s obviously considered to be possible for the fuel to instantly explode at that speed, since that’s supposedly the official explanation. But is it a given that it would happen? Let’s just say, for the sake of argument, that you wanted to engineer such an event. Would you be guaranteed that the plane would explode and cause a massive fire in the building merely from the impact, or is there a possibility that the plane might just pass through without all the fuel igniting, therefore requiring an ignition source just to be sure? What I’m thinking about here is how, in movies, cars always explode when they crash, while in real life, that rarely happens. Of course cars aren’t going 600 mph or whatever the speed of the plane was. I’m no physics expert, so I honestly don’t know the answer to that question.

Basically what I’m looking for is a real iron-clad debunking of this theory. I’m not really interested in rolleyes or “that’s so stupid” type comments; that goes without saying. I would be very interested in hearing from anyone who has heard a good debunking, or has the technical knowledge to evaluate what would cause flashes of light like that.