# So are there any pieces of evidence regarding a 9/11 conspiracy which cannot be explained? **URL:** \ **Category:** Great Debates\ **Created:** [September 2, 2009, 8:33pm UTC](https://boards.straightdope.com/t/so-are-there-any-pieces-of-evidence-regarding-a-9-11-conspiracy-which-cannot-be-explained/508677 "2009-09-02T20:33:21Z")\ **Posts on this page:** 11\ **Page:** 6
**Author:** ![Larry\_Borgia](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/larry_borgia/32/156_2.png) [@Larry\_Borgia](https://boards.straightdope.com/u/Larry_Borgia)\ **Post date:** [September 7, 2009, 4:24pm UTC](https://boards.straightdope.com/t/so-are-there-any-pieces-of-evidence-regarding-a-9-11-conspiracy-which-cannot-be-explained/508677/101 "2009-09-07T16:24:37Z")
**Alex** Could You explain what motive the Shadow Cabal had for blowing up WTC 7? As I understand it the CT is that the towers were blown up as a false flag operation to enrage the public and get them to accept the invasion of Iraq. How did blowing up building 7, with no deaths, further this goal? Wouldn’t the collapse of the towers be sufficient. In fact, I suspect that outside Conspiratorialists and Debunkers, most of the American public is barely aware of building 7. ---
**Author:** ![bup](https://avatars.discourse-cdn.com/v4/letter/b/6bbea6/32.png) [@bup](https://boards.straightdope.com/u/bup)\ **Post date:** [September 7, 2009, 4:30pm UTC](https://boards.straightdope.com/t/so-are-there-any-pieces-of-evidence-regarding-a-9-11-conspiracy-which-cannot-be-explained/508677/102 "2009-09-07T16:30:13Z")
Well, it’s all pointless. The problem, as has been hinted at with the ‘god in the gaps’ post, is that you can’t prove a negative. So the question in the OP can never be dealt with fully. No matter how many conspiracy theory claims have been dealt with, all the nutters have to do is come up with one more claim. ---
**Author:** ![DanBlather](https://avatars.discourse-cdn.com/v4/letter/d/f4b2a3/32.png) [@DanBlather](https://boards.straightdope.com/u/DanBlather)\ **Post date:** [September 7, 2009, 5:07pm UTC](https://boards.straightdope.com/t/so-are-there-any-pieces-of-evidence-regarding-a-9-11-conspiracy-which-cannot-be-explained/508677/103 "2009-09-07T17:07:46Z")
> [@Alex\_Dubinsky](#): > > While objections to the collapse behavior of the twin towers can be chalked up to “what they should have looked like,” in the case of WTC7 it’s possible to be a bit more concrete. In its collapse, you can see a crease formed in the center. The crease is leading the rest of the collapse by some small fraction of a second. If the collapse started as a chain reaction emanating from the crease, it would have to radiate a distance of up to 70 meters within that fraction of a second. For the sake of argument let us say the time delta is 0.2s. That comes out to a propagation velocity of 350 m/s, or approximately the speed of sound in air. But that’s the beauty of it. If it had been planned so that it looked like it fell down the way buildings are expected to after being hit by debris falling from great heights when an airplane full of fuel hits a neighboring building, then it would be “too perfect” and obviously a conspiracy. Instead, they placed explosives all around the perimiter so it looked suspicious, thereby proving that it _wasn’t_ a conspiracy except to the few cognesenti who saw past it. ---
**Author:** ![Alex\_Dubinsky](https://avatars.discourse-cdn.com/v4/letter/a/dbc845/32.png) [@Alex\_Dubinsky](https://boards.straightdope.com/u/Alex_Dubinsky)\ **Post date:** [September 7, 2009, 5:19pm UTC](https://boards.straightdope.com/t/so-are-there-any-pieces-of-evidence-regarding-a-9-11-conspiracy-which-cannot-be-explained/508677/104 "2009-09-07T17:19:30Z")
> [@Larry\_Borgia](#): > > **Alex** Could You explain what motive the Shadow Cabal had for blowing up WTC 7? As I understand it the CT is that the towers were blown up as a false flag operation to enrage the public and get them to accept the invasion of Iraq. How did blowing up building 7, with no deaths, further this goal? Wouldn’t the collapse of the towers be sufficient. In fact, I suspect that outside Conspiratorialists and Debunkers, most of the American public is barely aware of building 7. No idea ---
**Author:** ![Larry\_Borgia](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/larry_borgia/32/156_2.png) [@Larry\_Borgia](https://boards.straightdope.com/u/Larry_Borgia)\ **Post date:** [September 7, 2009, 6:45pm UTC](https://boards.straightdope.com/t/so-are-there-any-pieces-of-evidence-regarding-a-9-11-conspiracy-which-cannot-be-explained/508677/105 "2009-09-07T18:45:44Z")
> [@Alex\_Dubinsky](#): > > No idea Well, there you are. So regardless of how strange the collapse may have looked it must be related to falling debris. The fact that it looked funny doesn’t really prove anything. ---
**Author:** ![Bryan\_Ekers](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/bryan_ekers/32/183_2.png) [@Bryan\_Ekers](https://boards.straightdope.com/u/Bryan_Ekers)\ **Post date:** [September 7, 2009, 8:58pm UTC](https://boards.straightdope.com/t/so-are-there-any-pieces-of-evidence-regarding-a-9-11-conspiracy-which-cannot-be-explained/508677/106 "2009-09-07T20:58:17Z")
> [@Alex\_Dubinsky](#): > > While objections to the collapse behavior of the twin towers can be chalked up to “what they should have looked like,” in the case of WTC7 it’s possible to be a bit more concrete. In its collapse, you can see a crease formed in the center. The crease is leading the rest of the collapse by some small fraction of a second. If the collapse started as a chain reaction emanating from the crease, it would have to radiate a distance of up to 70 meters within that fraction of a second. For the sake of argument let us say the time delta is 0.2s. That comes out to a propagation velocity of 350 m/s, or approximately the speed of sound in air. I can’t make out the detail you’re describing, nor am I clear on why (if it exists) it proves anything. ---
**Author:** ![CannyDan](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/cannydan/32/548_2.png) [@CannyDan](https://boards.straightdope.com/u/CannyDan)\ **Post date:** [September 8, 2009, 4:07pm UTC](https://boards.straightdope.com/t/so-are-there-any-pieces-of-evidence-regarding-a-9-11-conspiracy-which-cannot-be-explained/508677/107 "2009-09-08T16:07:19Z")
> [@Alex\_Dubinsky](#): > > Surely they at least know what planes all the other blips are. Or you’re suggesting that modern airtraffic control is ludicrously flawed? Why even have radar if it’s just, “oh, look, a whole bunch of blips making pretty pictures.” > [@Joe Frickin Friday](#): > > I don’t know much about air traffic control, so I hope a professional will chime in here. > > But if radar tracking difficulties seem implausible, I’ll note that this was only a factor for Flight 77. For the other three planes, there just wasn’t enough time between figuring out that a hijacking had taken place (or informing the military about it) and the crash for meaningful action. I’m not an ATC professional, but frankly, no, they don’t know what all the little blips are. At least not just from the blips. In order to know what a particular blip might be, it would be necessary to actually follow it from takeoff through landing, originating an identification at wheels-up and continuing the identification through touchdown. This is not done, nor is it reasonable to expect. “Radar” for civilian aeronautics isn’t some magic world map, capable of infinite expansion and contraction with greater or lesser detail, like the zoom in and out in Google Earth. Separate radars “cover” specific geographic areas, at different scales. Airport coverage is different from area coverage, which is different from regional coverage. In the hypothetical complete tracking system you seem to envision, aircraft would need to be handed off from one radar operator to another, maintaining identification, as each moves off the edge of one operator’s screen and onto the edge of another operator’s screen. With 4,000 to 5,000 flights in the air at any given time in North America alone, this is impossible. Instead, airliners carry radar transponders, transmitting devices that provide specific identification to any and all radar screens on which they appear. Turn off this transponder and you become an unidentified blip. You are effectively (note ‘effectively’) invisible among all the other blips, including other unidentified returns that are background noise and not aircraft. And turning off the transponders was apparently one of the first actions the terrorists took after taking over the cockpit(s). Even if the specific aircraft could have been immediately identified on radar, and ignoring the problematic speed of the events, and supposing that military aircraft could have caught up with the airliners at any point before KABOOM, what exactly is proposed as the proper response? Shoot 'em down? These were civilian airliners, carrying civilian men, women and children, in a time of peace, over the airspace of the United States. We’ve had hijackings for decades, and never (to my memory) shot one down in flight. As far as I know, the protocol in the event of hijacking (until 9/11 anyway) was to cooperate and fly the plane to the destination demanded by the hijackers. The military certainly had no advance permission to shoot down a commercial airliner simply because it had been hijacked. Even after the first plane impacted WTC, permission to shoot down another hijacked aircraft would not have been automatic. This would require reversal of long standing policy, and would certainly require review at the highest levels of command. The scenario was brand new, and I cannot envision any military commander taking such a step unilaterally. An American military plane deliberately shooting down an American civilian flight over American soil was surely well outside the envelope of any training the fighter jock or his immediate commander might have as rules of engagement for a hijacking. Finally, an order to shoot the plane(s) down would also need to be cognizant of the consequences of ‘shoot down’-- the fact that there may well be something valuable and/or inhabited in that area generally described as ‘down’. Firing a missile at a huge multi-engined modern airplane isn’t going to make it go POOF and disappear. Even if it is immediately rendered unairworthy, there will be huge chunks raining down on possible population below. Short of that, it is possible that a missile might only take out an engine or two, but allow the determined suicidal maniacs inside to still fly it into a target of opportunity nearby, if not their original target. No, the military response was completely appropriate, and not at all evidence of any conspiracy. ---
**Author:** ![CurtC](https://avatars.discourse-cdn.com/v4/letter/c/ce73a5/32.png) [@CurtC](https://boards.straightdope.com/u/CurtC)\ **Post date:** [September 8, 2009, 4:21pm UTC](https://boards.straightdope.com/t/so-are-there-any-pieces-of-evidence-regarding-a-9-11-conspiracy-which-cannot-be-explained/508677/108 "2009-09-08T16:21:48Z")
> [@CannyDan](#): > > Instead, airliners carry radar transponders, transmitting devices that provide specific identification to any and all radar screens on which they appear. Turn off this transponder and you become an unidentified blip. My understanding of this is that when a transponder is turned off, you don’t become an unidentified blip, you disappear from the controller’s screen completely. That’s because they normally use something called “secondary” radar, which shows only returns from transponders. They have the ability to switch to “primary” radar, at which point they see a sea of blips without identification - blips from real airplanes and everything else. Finding an uncooperative plane on primary radar is a painstaking, time-consuming process. > [@](#): > > Even after the first plane impacted WTC, permission to shoot down another hijacked aircraft would not have been automatic. This would require reversal of long standing policy, and would certainly require review at the highest levels of command. The scenario was brand new, and I cannot envision any military commander taking such a step unilaterally. It’s pretty well documented when the permission was given. Bush, aboard AF1, talking to Cheney, just before 10:00, and communicated to the military shortly thereafter. However, Flight 93, the last of the four planes, crashed in Pennsylvania at 10:03, before the orders could be carried out. ---
**Author:** ![CannyDan](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/cannydan/32/548_2.png) [@CannyDan](https://boards.straightdope.com/u/CannyDan)\ **Post date:** [September 8, 2009, 4:43pm UTC](https://boards.straightdope.com/t/so-are-there-any-pieces-of-evidence-regarding-a-9-11-conspiracy-which-cannot-be-explained/508677/109 "2009-09-08T16:43:17Z")
> [@CurtC](#): > > My understanding of this is that when a transponder is turned off, you don’t become an unidentified blip, you disappear from the controller’s screen completely. That’s because they normally use something called “secondary” radar, which shows only returns from transponders. They have the ability to switch to “primary” radar, at which point they see a sea of blips without identification - blips from real airplanes and everything else. Finding an uncooperative plane on primary radar is a painstaking, time-consuming process. > > It’s pretty well documented when the permission was given. Bush, aboard AF1, talking to Cheney, just before 10:00, and communicated to the military shortly thereafter. However, Flight 93, the last of the four planes, crashed in Pennsylvania at 10:03, before the orders could be carried out. I believe you are correct about primary and secondary “systems”. While the vernacular is “primary and secondary radars” this is shorthand for the overlay of software that provides the identifications. I believe (but am too lazy to look for a cite, since I doubt it changes the discussion significantly) that different ATC sub-commands have different implementations of these systems. This makes transmitting information about a problematic blip from, say, the Pennsylvania regional controller to, say, the DC close approach airports controller difficult if all they can do is say “Yeah, that one there, near the Continental heavy and approaching the Valuejet” into a telephone. Yes, painstaking and tedious does describe the process. I didn’t know that Bush actually gave the order. Thank you for that information. I wonder exactly what caveats were a part of it-- shoot now, or shoot over farm or forest, or shoot if they won’t turn from course after close approach, or whatever. Just curious. ---
**Author:** ![ElvisL1ves](https://avatars.discourse-cdn.com/v4/letter/e/5daacb/32.png) [@ElvisL1ves](https://boards.straightdope.com/u/ElvisL1ves)\ **Post date:** [September 8, 2009, 5:16pm UTC](https://boards.straightdope.com/t/so-are-there-any-pieces-of-evidence-regarding-a-9-11-conspiracy-which-cannot-be-explained/508677/110 "2009-09-08T17:16:15Z")
> [@Alex\_Dubinsky](#): > > it’s very hard to imagine circumstances where a large and wide structure would transmit force over the entire distance of its span within a fraction of a second, and that the force prove critical to all regions. If someone wants to be puzzled by some element of 9/11, they should be puzzled by the right thing… The name of that puzzling force is “gravity”. ---
**Author:** ![Algorithm](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/algorithm/32/12204_2.png) [@Algorithm](https://boards.straightdope.com/u/Algorithm)\ **Post date:** [September 8, 2009, 5:42pm UTC](https://boards.straightdope.com/t/so-are-there-any-pieces-of-evidence-regarding-a-9-11-conspiracy-which-cannot-be-explained/508677/111 "2009-09-08T17:42:18Z")
> [@Alex\_Dubinsky](#): > > [Obligatory collapse vid.](http://www.youtube.com/watch?v=oQeQi5XXfz0) I’d never really noticed before, but at about 0:23 - 0:24, towards the end of the visible collapse, you can see the top of the building tip over quite a bit as it falls. “Near-perfect symmetry” probably isn’t the term you’d use to describe that. [Previous page](https://boards.straightdope.com/t/so-are-there-any-pieces-of-evidence-regarding-a-9-11-conspiracy-which-cannot-be-explained/508677.md?page=5)