I have told you what was needed to have your stuff taken seriously. You need to state how the building should have collapsed if it were structurally weakened, and why it did not, and (I may or may not have added this) you need to present a hypothesis for what happened. That would include the "computer controlled" top-down detonation that Mr. Chandler says the video "indicates". Where was the computer? Who operated it? How was it linked to the detonated material? Who set the charges? When? How did they decide how to make the building collapse with no prior experience either in 110 storey building detonation or in top-down detonation?

I would agree with the video you linked to that the building rooftop does not appear to move before frame 46. That's all I would draw from the video. BTW, Mike Sulzer had calculated for you last knock-down-drag-out that it would approach near free fall speed very quickly. But the twin tower collapses show very clearly that they are sub-free fall acceleration. By a much more accurate method of determining that than counting frames: The speed is superceded by the speed of the fastest debris, which, as you noted, left the building horizontally, and therefore owes all of its downward motion to gravity.

I have absolutely no contempt for teaching physics. Honorable profession. But unless he also does research and publishes, or has a side job working in industry, he isn't a working physicist. That's all.

David has a BS from Harvey Mudd College, Claremont, CA (IPS major–independent program of studies with emphasis in physics and engineering); MA in education from Claremont Graduate University; MS in mathematics from Cal Poly, Pomona and has taught Physics/Mathematics/Astronomy at K-12 and Jr. college levels. He is also and author and served formerly on the editorial board of The Physics Teacher, an AAPT journal. David is also an active designer and inventor of educational materials emphasizing quantitative visualization.

Wow, LondonLad. I gotta hand it to you, I learned something! I didn't know Cal Poly had a Master's program! Now why don't you email Mr. Chandler and see about that working hypothesis thingy? If he's responsible for teaching California high school and Jr. College students in physics on my tax dollars, he should know that -- or get fired.

Oh, and by the way, don't tell Mike Sulzer that this guy is listed as a "Physicist" on your websites. He might get a little ticked. The guy is not a working physicist.

Laugh all you like, I hope you enjoy it. What it means is before performing an experiment, or, in this case, examining forensic evidence, you need a working hypothesis. Your guy Chandler's working hypothesis is a controlled demolition, the NIST investigators' hypothesis was that the building came down due to structural failures caused by the planes.

It's very, very basic science. So have a good time laughing. It's up there with laughing about what I said about the veracity of theorems. Please do distribute your new find far and wide. The more places you laugh about it, the more you will paint yourself as a crackpot. Like I said, you should try learning some real science. At least so this doesn't keep happening to you.

Hypothesis precedes observation. Basic rule of experimentation. I have no frigging idea where Dealy Plaza is. Why don't you just run along and study some real science. I'll give you a hint: Calculus and Newtonian Physics were invented simultaneously. You can't do one without the other. Headboning it on logic went out with Aristotle.

There are no specifics in the Chandler preparations except to note girders expelled by the collapse at speeds of 60 or 70 miles an hour. There is no consideration for whether or not the outer frame is collapsing at the same speed as the interior, there is no real consideration (some words said, but no careful consideration) about the "tops of the building", which he speaks of as if they were supposed to remain completely intact on the way down. Most of all, there is no consideration, like I told you, of how a building collapsing from major structural damage at the 90th of 110 floors should collapse, which since he is contending didn't happen, he needs to address. It's junk, and certainly not science.

And by the way, the fact that there are pieces of building falling below the mysterious line which he notes is below the descending top of the building, all add up to the top of the building most definitely not falling at the speed of free fall.

Now that I've addressed Chandler, please generate the material I told you you needed before addressing the subject again.