The Twin Towers at free fall speed

[Thunder]

wait....so free-fall speed= controlled demolition...and not free-fall speed= no controlled demolition?

truthers are very stupid.

 

[9/11 Chewy Defense]

It's quite obvious that the Truthers never clearly understood the "Theory of Relativity" when Albert Einstein thought of it, after Max Planck when he thought of it in 1908.

 

[tsig]

wait....so free-fall speed= controlled demolition...and not free-fall speed= no controlled demolition?

truthers are very stupid.

Using contradictory facts to prove the same thing seems to be the truthers favorite tactic.

My favorite is:

They fell into their footprints = CD

Beams thrown 600 feet = CD

 

[cyclonic]

Nice Cyclonic... very clearly shows that WTC1 and 2 collapse at way less than freefall speed.

So why doesn't Richard Gage and his 9/11 truth cult admit this fact and try and work their lunatic theory around some honest observations? Truthers cant pretend he hasnt seen these.

If the fall took 14.5 seconds, which is the fast end of your range then the collapse took place at 40%g. So a large part of the potential energy was not converted into kinetic energy implying there was substantial resistance.

Why do they lie.? Can any truther on this forum explain?

To all 9/11 truthers,
Why do you want to believe 9/11 was an inside job so badly that you ignore facts, evidense,lose friends and fight with family members,why?

 

[alexi_drago]

It doesn't fall faster. It begins falling earlier.

Erm, have I picked this up right?

The collapse front was coming down at freefall but debris also falling at freefall appeared to be ahead of it because it began falling earlier? even though the debris all came from the collapse front?

 

[sylvan8798]

Erm, have I picked this up right?

The collapse front was coming down at freefall but debris also falling at freefall appeared to be ahead of it because it began falling earlier? even though the debris all came from the collapse front?

Don't ya love it when they try to look like they know what they are talking about? Sooo cute!

 

[Edx]

Using contradictory facts to prove the same thing seems to be the truthers favorite tactic.

My favorite is:

They fell into their footprints = CD

Beams thrown 600 feet = CD

explosion sounds! = CD

no explosion sounds! = CD

 

[Alferd_Packer]

I like this comparison

Each of the Twin Towers fell completely in intervals of time similar to that taken for a block of wood dropped from a tower's roof to reach the ground. A block of wood has about the same average density as the main components of the towers near their tops.

concrete and steel have the same density as wood.

 

[Furcifer]

I like this comparison
concrete and steel have the same density as wood.

So the Towers were a witch? Or a duck? A really small rock?

 

[JimBenArm]

So the Towers were a witch? Or a duck? A really small rock?

Let's build a bridge out of them!

 

[jay howard]

The amount of time it took for


That is NOT the full collapse time. Which is longer. The full collapse time was over 15 seconds on the first tower and over 20 seconds on the second one.

The first outer columns broke away and WERE falling at freefall, as opposed to the collapse.

that alone is proof that there was NO freefall

Is this backed up in the NIST report or are you just pointing to some youtube knowledge?

To be precise here, I do NOT advocate calling the collapses "free fall". I DO advocate calling the collapses "near free fall speeds". At any rate, the buildings fell extremely fast. Can anyone argue with that?

"Fast compared to what?" they asked.

Compared to buildings that are damaged at the upper floors but have no appreciable damage to the overwhelming majority of supporting floors.

This is about as silly a conversation as it gets. The buildings fell fast. No question. No arguing. Sure, you could say (and I wouldn't disagree) that the buildings did NOT fall at precisely free fall speed, but that doesn't dispell the questions that arise from such a rapid and thoroughly destructive fall.

Why is it so incredulous to ask why the buildings, whose supporting members below the respective crashes were purportedly intact, fell at such a rapid rate as to incite a debate about whether they fell at free fall speeds or slightly less?


.

 

[Reactor drone]

Why is it so incredulous to ask why the buildings, whose supporting members below the respective crashes were purportedly intact, fell at such a rapid rate as to incite a debate about whether they fell at free fall speeds or slightly less?


.

Perhaps because the question ignores the fact that the supporting members below the collapse point were no longer acting as supporting members and by saying "free fall speed" or "near free fall speed" isn't at all accurate.

So if you say things which aren't accurate and misrepresent the structural collapse people might get the impression that you were being deliberately dishonest in order to push some kind of political agenda.

 

[Newtons Bit]

"Fast compared to what?" they asked.

Compared to buildings that are damaged at the upper floors but have no appreciable damage to the overwhelming majority of supporting floors.

Do you have a list of buildings that fit this criteria where the following collapses were timed? This is rhetorical, I already know that you don't have such a list. What I would like to know is: what are you actually comparing the WTC collapses to? This is also rhetorical, we both know already that there is nothing comparable or indeed measured. Which follows: what is your real motive? But that's rhetorical as well, everyone here already knows.

By the way, that quote from NIST that you linked is the time it took from collapse initiation to the first piece of debris to strike the ground. If you can't figure it out yourself, that piece of debris wasn't falling through the entire building, it was an exterior panel that fell out of the building footprint. It actually fell at a free-fall speed. The rest of the building did not.

 

[jaydeehess]

I like this comparison



concrete and steel have the same density as wood.

Well I suggest and experiment for the tM.

Take three blocks all the same dimensions but one of steel, one of concrete and one of wood, and lower them into a large water filled container. Anything that is denser than water will sink, less dense than water and it will float. All the same desity and they should all behave in the same manner.
That should settle the issue of " about the same average density "

 

[Furcifer]

Well I suggest and experiment for the tM.

Take three blocks all the same dimensions but one of steel, one of concrete and one of wood, and lower them into a large water filled container. Anything that is denser than water will sink, less dense than water and it will float. All the same desity and they should all behave in the same manner.
That should settle the issue of " about the same average density "

"The Towers burned for several hours"
"That's rwight, they deed"
"And what else burns?"
"Toast?"
"Yes, but what else?"
"Little bits a paper?"
"Rwight, but what else?"
"Them thinns wif a head on em'?"
"Matches!"
"Thass wright, matches, they burn good"
"Yes, matches, but what are matches made uf?"
"I knowz, its thr'mite, thr'mite burns!"
"Yes, that too, but wha else?, keeps you warm at nite?"
"Blankets?"
"Bloody hell man, not blankets, in a stove"
"wood?"
"Ass rwight, wood, wood burns!"
"An the towers, they burned too!"
"Ass wright, the towers burned and wood burns, so the towers is made uh wood"
"And matches!"

 

[jay howard]

Perhaps because the question ignores the fact that the supporting members below the collapse point were no longer acting as supporting members and by saying "free fall speed" or "near free fall speed" isn't at all accurate.

What?

So if you say things which aren't accurate and misrepresent the structural collapse people might get the impression that you were being deliberately dishonest in order to push some kind of political agenda.

Right. Just like you're a government shill.

As usual, no attempt at a rational discussion here. Why is it so hard to have a rational, adult conversation about anything related to this? Because you're already had the conversation? If that's the case, then just don't reply. If you want to reply, then have a real conversation.

 

[Alferd_Packer]

Well I suggest and experiment for the tM.

Take three blocks all the same dimensions but one of steel, one of concrete and one of wood, and lower them into a large water filled container. Anything that is denser than water will sink, less dense than water and it will float. All the same desity and they should all behave in the same manner.
That should settle the issue of " about the same average density "

The person who linked that page in another forum tried to backtrack by claiming that the air inside the building is a major component of the building. thus, the building had the same density as wood, and thus should have fallen at the same speed as a block of wood.

 

[Alferd_Packer]

Why is it so incredulous to ask why the buildings, whose supporting members below the respective crashes were purportedly intact, fell at such a rapid rate as to incite a debate about whether they fell at free fall speeds or slightly less?


.

The fact that the supporting strucutre was intact below the impact point is trivial when you consider the amount of kinetic energy generated by the top of the strucutre at the onset of the collapse.

 

[jaydeehess]

To be precise here, I do NOT advocate calling the collapses "free fall". I DO advocate calling the collapses "near free fall speeds". At any rate, the buildings fell extremely fast. Can anyone argue with that?

I agree, once the collapse was initiated it could be characterized as occuring 'fast'.

"Fast compared to what?" they asked.

Compared to buildings that are damaged at the upper floors but have no appreciable damage to the overwhelming majority of supporting floors.

Such as..................? In the few occurances in which partial collapses have been videoed we see similar acellerations. There has never been a situation in which 110 storeys have come down though and in ANY situation in which the material is acellerating it will, by definition, see increasing speeds.

This is about as silly a conversation as it gets. The buildings fell fast. No question. No arguing. Sure, you could say (and I wouldn't disagree) that the buildings did NOT fall at precisely free fall speed, but that doesn't dispell the questions that arise from such a rapid and thoroughly destructive fall.

Thus begins your foray into personal incredulity...

Why is it so incredulous to ask why the buildings, whose supporting members below the respective crashes were purportedly intact, fell at such a rapid rate as to incite a debate about whether they fell at free fall speeds or slightly less?
.

Well if the TM is willing to drop the "faster than free fall speed", "free fall speed", and "near free fall speed" labels I'm all for it, and since THAT is why there is a debate you are asking the wrong people.

If the debate is driven by one group attempting to illustrate that explosives were required to accomplish the destruction observed then it is neccessary to get into details and one such detail that the TM is focused upon is the time of collapse duration.

They show themselves to be utterly unequiped for a discussion of physics when they use the term 'speed' when describing the time of collapse duration or the condition of 'free fall'. The condition of 'free fall' involves an acelleration which means (by definition) that the 'speed' is increasing continuously so 'free fall speed' is meaningless unless one is actually concerned with the velocity of the collapse zone at a particular time, or possibly height.

The time it took for the perimeter colllapse zone to reach the ground is well over the time it would have taken for an object to free fall from the height of the towers and if one includes also the core collapse(i.e. the total time of collapse) we get something on the order of twice that time.

If something falls at an acelleration of 'g' (32 ft/s/s) from (let's use round numbers) 1200 feet it will take 8.7 seconds.

What would its acelleration be if it took twice that time? 7.9 ft/s/s
Well,,, a doubling of the time to fall decreases the acelleration by a factor of 4!! Since Force is equal to mass times acelleration and we have quartered the acelleration then the total force was also quartered. This was not accomplished by lowering the acelleration due to gravity but by having a oppositely acting constant force on the mass that was 3/4 that of the force due to gravity.

But but but the TM cries, the building was capable of supporting more than its weight due to gravity and yes, it was IF, IF, IF the building was in the intact condition it was up to the time of impact. These are all static loads and bear no relevence to how the building would react to dynamic loading nor how the building's structural components will react to dynamic and static loading that does not conform in any way to the way it was designed to take loads. If a mass greater than that which the floor spans were capable of supporting was on that floor then it (the floor) would fail and it would not matter a whit that the columns could support that load with no problem. If the load was predominantly dynamic overloading the situation is again changed and basically the floor fails in even less time..

Detail, detail, detail and when details show, as they inevitably do, that the building certainly could succumb to naturally occuring forces and that explosives or therm(?)te would not be required, the TM proclaims that their vague claims of incredulity trump actual physics when in fact the tale that physics tells was originally their idea.

 

[jay howard]

Do you have a list of buildings that fit this criteria where the following collapses were timed? This is rhetorical, I already know that you don't have such a list. What I would like to know is: what are you actually comparing the WTC collapses to? This is also rhetorical, we both know already that there is nothing comparable or indeed measured. Which follows: what is your real motive? But that's rhetorical as well, everyone here already knows.

My real motive is to make everyone write left-handed, of course. But that's not what this conversation is about. What this is about is visualizing what happened to the complex interconnected network of steel beams below the crash areas such that it was unable to slow the falling mass enough so that we might avoid this conversation.

The NIST account says the steel was heated to the point of "collapse initiation" however, nowhere in their report do they even attempt to address what happened after "collapse initiation".

As far as they're concerned, the collapse was "inevitable" after a certain point, and that's all that needs to be said about it. Being a "skeptic" (you may have heard this term before), that is not a satisfactory answer for me. So to entertain a conversation about what was happening to the steel members such that the longest any of the three buildings lasted from beginning of collapse to pile of rubble was 20 seconds, seems like a reasonable request.

By the way, that quote from NIST that you linked is the time it took from collapse initiation to the first piece of debris to strike the ground. If you can't figure it out yourself, that piece of debris wasn't falling through the entire building, it was an exterior panel that fell out of the building footprint. It actually fell at a free-fall speed. The rest of the building did not.

You want to say it was 15 seconds for WTC 2 and 20 seconds for 1? Fine. It still doesn't dispell a rational examination of those collapses.