I just wish Mr Chandler would join and address this. If Mr. C was a member then William Seger couldn't easily call names an insult because it's against DU rules! Thanks in advance.
Here's a cut & paste;

"Yup, hard evidence that Chandler is both incompetent and disingenuous

"I think it's important that we start at a very intuitive level, just looking at the event."

But not looking too closely, apparently. This is going to be a long post because Chandler packs a lot of bullshit into this video, but if you can ask us to watch it, I think it's fair to ask you to read the whole thing.

"What we see when the north tower is coming down is along the edge of the building you can see jets being expelled very violently. These are clearly explosions."

No, they are not explosions; he was right the first time to call them "jets" since they are clearly pneumatic air flows. When you watch a video of an actual explosion, what you see is that the cloud of smoke appears very suddenly and then the expansion of the clould slows down. That's exactly what you'd expected when the force driving the expansion is a shock wave that lasts a small fraction of a second. However, in the WTC videos that Chander claims to see "clearly," we see clouds of smoke and dust exit the building and then speed up. That's because the force driving them is air being forced out of the collapsing building, and that continuing force produces continuing acceleration. A physics teacher ought to understand that, but Chandler apparently doesn't feel compelled to explain things that he can simply ignore.

"... something very energetic is going on here."

Duh, ya think? A physics teacher ought to be able to calculate that the gravitational potential energy stored in the buildings was equivalent to about 200 tons of TNT. I'd call that "very energetic" but Chandler just blithely ignores that energy in his analysis. And once again, Chandler just ignores the issue of what it would sound like if what we're seeing in the videos was caused by tons of TNT.

"It's difficult to take concrete and reduce it to powder."

Chandler gets one right, but then in his blindness, he simply refuses to see why that causes a problem for his controlled demolition theory. Reducing concrete to powder with explosives is indeed very difficult, and cutter charges on the columns would have produced virtually no pulverization of the floors. To pulverize the floors with explosives, you'd need to put huge charges all over the floors of these occupied office buildings, which (besides being an absurd speculation) would be perfectly pointless for a controlled demolition, anyway. Furthermore, it's really hard to believe that a physics teacher doesn't understand that explosives are not silent. Just using enough to cut the columns would have produced a distinctive sound that would easily have been heard for miles, but the idea that huge amounts of silent explosives were planted all over the building to pointlessly pulverize the floors is beyond idiotic. On the other hand, in a Verinage demolition, which doesn't use any explosives at all, we see that concrete is pulverized by nothing but gravitational energy as the debris is ground up in the collapse. Furthermore, Chandler seems to be oblivious to the fact that in an actual controlled demolition, it's only necessary to blow out columns on one or two levels and let gravity do the rest, including pulverizing concrete. It's certainly not the cutter charges that do it.

"It takes a lot of energy to reduce the concrete to micron-sized powder."

Yes, but it also takes an efficient way to get the energy into the concrete, which is exactly why an explosives expert could have informed Chandler, had he bothered to ask, it is difficult to do that with explosives (or any other means of creating a single impulse force, such as a single blow with a hammer). On the other hand, chunks of concrete colliding and grinding together and being battered with heavy steel members in a chaotic collapse would absorb energy and fracture with every blow, all the way down. Bazant demonstrated there was much more than enough gravitational energy to cause the structure to fail and Frank Greening demonstrated that there was much more than enough left over to explain the concrete pulverization, but Chandler prefers delusional fantasies about silent explosives planted all over the building for no logical reason whatsoever.

"This was dust before it ever hit the ground... There's very little concrete in the actual rubble pile. What we see in the rubble pile is steel, and the concrete has been spread all over Manhattan."

That is a lie. A thick layer of dust (which contained more fiberglass, drywall, ceiling tile and other dust than it did concrete) which had been suspended in the air fell on top of the debris pile and "all over Manhattan." If Chandler is baffled by why so much dust was produced before the rubble hit the ground, then he is too easily baffled to be investigating a building collapse. But under the dust, the upper layers of the debris pile contained considerable amounts of small chunks of concrete from the upper floors (which had fallen farther and so had been ground up more than lower floors), and underneath that there were fairly large chunks of concrete. Instead of any actual evidence for his claims, Chandler presents imaginary evidence which is contrary to the actual evidence.

"At the very onset of collapse, the very first motion you can see is this {the antenna} descending."

In videos shot looking up at the north wall, it appears that way, but in videos taken from the side, the first motion you can see is the antenna tilting south, away from those cameras looking from the north. For some reason, Chandler doesn't like that evidence.

"It wasn't down here where the break occurred."

Not "down here" in that video, perhaps, because the collapse began on the other side of the building, and then the top tilted away from that camera. Surely, Chandler knows this by now but chooses to ignore the perspective illusion the tilting top would produce from that viewpoint. After ignoring the evidence of the tilt and its effect on his 2D image, he informs us that the only conceivable explanation he can come up with is that all the core columns were "removed suddenly and completely." (Actually, to get the antenna to fall through the roof first, you'd also need to blow up the "hat trusses" at the top, but "truthers" apparently don't have trouble imagining that the "perps" concocted pointlessly complicated, risky and bizarre schemes, for some unexplained reason.)

"It turns out that the descent of the tower was not at a constant speed. It was picking up speed as it went, and that's called acceleration. If you graph the descent of the north tower, you can see that it actually accelerated all the way, the entire time that the roofline is visible. Now that's very significant. For something to be accelerating downward, it means that the net force acting on it is downward, okay? Now, there's two forces at work here. There's gravity and there's resistance, and if the net force is downward it means that the resistance is less than gravity, because the net force has to dominate downward. Therefore, it tells us that the resistive force was less than the weight of the block."

At this point, Chandler shows a diagram claiming that the measured acceleration of the collapse was 0.64g, so the resistive force must have only been 0.36 times the weight of the building. In the other video you posted of him giving a live lecture, he was more specific that he had calculated a "uniform" acceleration of 0.64g, and that the problem he couldn't explain without a controlled demolition was why a structure that had been designed to withstand 300% of the weight of the building was only providing 0.36% or that weight as resistance. Obviously, says Chandler, about 90% of the strength of the structure "must have been removed."

Surely, Chandler has heard the explanation many times by now, but he keeps making the same ridiculous claim. The problem is that he has plotted some points on a graph, drawn a straight line through them, and then claims that his own straight line is proof that the acceleration was "uniform!" But just think about what that would really mean if it were true: Imagine there was a camera on one of the WTC floors when the collapsing tower debris hit the floor above: Would you expect to see the ceiling instantly take on the velocity of the falling mass and then accelerate "uniformly" at 0.64%g down to the floor?

The "uniform acceleration" claim is nonsense. Chandler seems to be unaware that a steel column can only offer its maximum resistance to a load for a few inches of compression. When it becomes plastic and begins to buckle, it doesn't just ease its load down to the floor at a "uniform" acceleration like a rock falling through water. The resistance rapidly drops toward zero and the failure is sudden, much like compressing the ends of a straw until it crimps. If the resistance becomes actually zero because the column breaks, the load it was carrying can fall at nearly 1g, slowed only by air resistance. That's how columns would behave if they were stressed into buckling, but we know that in most cases, the floor trusses were ripped away from beams and beams were ripped away from columns. Those failures would have happened over a much shorter distance and absorbed less energy than column buckling, leaving the floor debris to freefall to the next floor, slowed only by the air.

The fatal flaw in Chandler's argument is that there is simply no rational reason to claim or to expect that the 0.64g acceleration was "uniform," regardless of what caused the collapse. The 0.64g is just an average over time, which includes periods of actual freefall. Likewise, the 0.36mg resistance is just an average over time, which includes brief times in some cases when the resistance was perhaps as much as 3 times the weight a column was designed to carry (but was overcome by the momentum that Chandler completely ignores), plus some periods and many failure modes where the resistance was much less than that, and quite a bit of time when the structural resistance was exactly zero. Even with much better resolution and precision than he had, there is no way that Chandler could hope to measure the deceleration caused by thousands of individual collisions and the subsequent freefall acceleration of thousands of pieces of debris after elements failed by simply plotting the position of the roof from a video. Mystery solved, because there's nothing mysterious about the 0.36mg average resistance over time. Furthermore, the proof is the Verinage type of demolitions, which would be impossible if Chandler were correct. Instead of being impossible, they show the same kind of average acceleration (and thus average resistance) as the towers, despite not having the lower part of the structure weakened as Chandler asserts would be required. Chandler's quasi-static analysis isn't just inadequate; it's absurd for the dynamic conditions in a collapsing building.

And his demolition conclusion is absurd for another reason: Removing 90% of the columns (or somehow weakening each by 90%) would CERTAINLY NOT produce the "uniform 0.64g acceleration" that Chandler imagines. The exact same failures described above would still have happened, only sooner, and we would have even longer periods of zero structural resistance and actual freefall. There simply isn't any plausible failure mode that would produce "uniform" acceleration. Does Chandler claim that supernanothermite fairy dust has magical powers beyond its ability to explode silently and then also burn for weeks?

But Chandler isn't nearly finished with being wrong; he next turns his attention to WTC 7:

"It fell at absolute freefall for the first hundred feet or so."

That's another baldface lie, since he knows his own data doesn't show freefall "for the first hundred feet." But Chandler chooses to simply ignore facts that don't fit his theory. His own plot shows the building came down at much less than freefall for the first 1.5 seconds (or 1.75 seconds according to NIST), falling seven feet or so, which simply does not fit the premise that the columns had been blown away. If the collapse started because columns had been blown away, the building should have started falling at freefall right from the start, so Chandler just lies and says it did. But that seven feet of less-than-freefall does fit the premise that the collapse started with column buckling, and then the freefall began only when about 8 floors had buckled and broken to the point that they offered no resistance. And in fact, that does fit NIST's collapse simulation, which showed the shell start to fall after columns progressively buckling across floors 7 to 15.

Chandler says that NIST just "waved their hands" and asserted that the data is consistent with their analysis, but NIST is in fact correct that it does, notwithstanding Chandler's willful ignorance of why they said that. On the other hand, I haven't yet heard a demolition theory that's consistent with the data which doesn't require some bizarre special pleading for that first 7 feet of slow fall and why the "perps" decided to blow out columns on eight floors after the building was already falling. And yet, Chandler uses his own ignorance as a basis for accusing NIST of trying to "cover up" the significance of his own misconceptions, and then uses that "cover up" as additional "evidence" that there was a conspiracy! Such is the delusional spiral that conspiracism leads to.

After promising us some evidence, Chandler disappoints by leaving his failed collapse arguments there and moving on to "reason" "II: High Temperatures." Chandler claims that there were times when the temperature was much hotter than can be explained by an office fire.

"in other words, if you take office furnishings, just a regular fire, and you throw in kerosene, and you say, 'How hot can this burn? Could that weaken the steel; could that allow this building to collapse?'

In character, Chandler again decides to ignore the experts who say the answer is "Yes!" and instead prefers to use his own misconceptions and imagination to come up with an answer that fits into his preconceived belief system. He begins with a deception:

"At first, the story line -- the 'official story' was that because the jet fuel was so hot that it melted the steel and so forth. Well, that didn't stand up very long; it was very quickly shown that kerosene, that -- kerosene is essentially jet fuel -- that this kerosene couldn't possibly get to a temperature that would melt steel."

There was never any "official story" that steel had "melted" into the liquid state. The term was used mainly by reporters and even they used it in the most casual sense, like you might say a stick of butter "melted" because it had lost is rectangular block shape, not because it had actually become a liquid.

But more importantly, structural engineers know exactly why steel structures can fail at temperatures well below the melting point of steel: it's called "viscoplastic creep," which is the slow, permanent deformation that happens to hot metal under constant stress. That was the "expert story" right from Bazant's first paper on 9/13, yet Chandler seems to have never heard of it:

So why did a total collapse occur? The cause was the dynamic consequence of the prolonged heating of the steel columns to very high temperature. The heating lowered the yield strength and caused viscoplastic (creep) buckling of the columns of the framed tube along the perimeter of the tower and of the columns in the building core.

There was no "government story" until NIST published its report, but nonetheless Chandler claims:

"So the government story changed at this point. Rather than asserting that the steel melted, they simply asserted that it was weakened."

After using his imaginary history to bolster his imaginary "government cover-up" speculation, Chandler admits that steel is indeed "weakened" by temperatures much less than the melting point. But not enough, claims Chandler, because:

"Experiments with actual steel structures show that if you take a steel-framed structure, it doesn't collapse {in a fire}!"

That's a lie, and a very stupid one. The favorite "truther proof" of this lie is the Windsor Tower, but that "proof" requires ignoring the fact that the steel-framed part of the building DID collapse. The part that didn't collapse was made of reinforced concrete. Many other steel structures have collapsed, so Chandler was supposed to say that steel-framed highrise office buildings must be exempt from total collapse for some unexplained reason, because it never happened before, never mind the science. And yet steel structures are fireproofed because sane people know that Chander's claim that steel-framed structures don't collapse is bullshit.

"There's another side of the story as well. It's very clear that the temperatures needed to melt steel were actually achieved, okay. One of the main pieces of evidence for this is that there's iron found in the dust == there are droplets of iron in the dust."

We were discussing the iron microspheres elsewhere, so I won't go into again except to say that Chandler has no evidence whatsoever that the microspheres were created during the collapse, and he wants to ignore that the first dust analysis by RJ Lee reported that the microspheres were of the same type as those found in a trash incinerator or coal-fired generator boiler, which also burn hydrocarbons at less than the melting point of steel. They simply are not any sort of "signature" of thermite burning.

"So, the fact that these iron spheres exist is very solid scientific proof that high temperatures were achieved."

Yeah, well, now how about some solid scientific proof that they were produced during the collapse, and then some solid scientific proof that only thermite could have made them? Not a shred? Why does Chandler want us to just assume those implausible things without proof while just ignoring all the more plausible explanations? What kind of "science" is that?

"It goes beyond that. There's observations that there was iron -- uh, molten iron, molten steel, whichever -- in the rubble pile; there's actual photographs of either molten iron or molten steel pouring out of the south tower just before it collapsed; so there's all of these converging lines of evidence that these high temperatures were in fact achieved."

On the one hand, Chandler wants to convince us that he is being scientific. On the other hand, he wants us to believe that molten iron or steel can be identified by "observations" and photographs. Calling those "observations" "evidence" does not make that claim any less laughable. There is no "solid scientific" evidence of any "molten iron or steel" pouring out of the building or in the rubble pile. (And for the "observations" in the rubble pile, I'm still waiting for an explanation for how thermite kept the "steel" molten for weeks.)

On to "reason" "III: Nanothermite," but I decided not to even waste the time it would take to watch this nonsense rehashed yet again. Harrit and Jones utterly failed to prove that chips which look exactly like the paint used to fireproof the floor joists underwent any thermitic reaction, or that they contained the elemental aluminum necessary for any such reaction. Independent analysis by an actual expert showed that they did not, but even without that analysis, Harrit and Jones' conclusions do not follow from their own data. The paper will never be taken seriously by materials scientists because the evidence just isn't there, Chandler's credulous yammerings notwithstanding, because Harrit and Jones didn't do the necessary experiments.

In short, Chandler promised evidence and then delivered another metric ton of bullshit, even though he ought to know better by now. And the really pathetic thing is that this bullshit is pretty much "truther science" at its best."

I just don't have time nor know enough to rebut it.