# WTC Towers: The Case For Controlled Demolition

S

#### schoenfeld.one

accurately accounts for the collapse times of the World Trade Center
towers. A top-down controlled demolition can be simply characterized
as a "pancake collapse" of a building missing its support columns.
This demolition profile requires that the support columns holding a
floor be destroyed just before that floor is collided with by the
upper falling masses. The net effect is a pancake-style collapse at
near free fall speed.

This model predicts a WTC 1 collapse time of 11.38 seconds, and a WTC
2 collapse time of 9.48 seconds. Those times accurately match the
seismographic data of those events.1 Refer to equations (1.9) and
(1.10) for details.

It should be noted that this model differs massively from the "natural
pancake collapse" in that the geometrical composition of the structure
is not considered (as it is physically destroyed). A natural pancake
collapse features a diminishing velocity rapidly approaching rest due
the resistance offered by the columns and surrounding "steel mesh".

DEMOLITION MODEL

A top-down controlled demolition of a building is considered as
follows

1. An initial block of j floors commences to free fall.

2. The floor below the collapsing block has its support structures
disabled just prior the collision with the block.

3. The collapsing block merges with the momentarily levitating floor,
increases in mass, decreases in velocity (but preserves momentum), and
continues to free fall.

4. If not at ground floor, goto step 2.

Let j be the number of floors in the initial set of collapsing floors.
Let N be the number of remaining floors to collapse.
Let h be the average floor height.
Let g be the gravitational field strength at ground-level.
Let T be the total collapse time.

Using the elementary motion equation

distance = (initial velocity) * time + 1/2 * acceleration * time^2

We solve for the time taken by the k'th floor to free fall the height
of one floor

[1.1] t_k=(-u_k+(u_k^2+2gh))/g

where u_k is the initial velocity of the k'th collapsing floor.

The total collapse time is the sum of the N individual free fall times

[1.2] T = sum(k=0)^N (-u_k+(u_k^2+2gh))/g

Now the mass of the k'th floor at the point of collapse is the mass of
itself (m) plus the mass of all the floors collapsed before it (k-1)m
plus the mass on the initial collapsing block jm.

[1.3] m_k=m+(k-1)m+jm =(j+k)m

If we let u_k denote the initial velocity of the k'th collapsing
floor, the final velocity reached by that floor prior to collision
with its below floor is

[1.4] v_k=SQRT(u_k^2+2gh)

which follows from the elementary equation of motion

(final velocity)^2 = (initial velocity)^2 + 2 * (acceleration) *
(distance)

Conservation of momentum demands that the initial momentum of the k'th
floor equal the final momemtum of the (k-1)'th floor.

[1.5] m_k u_k = m_(k-1) v_(k-1)

Substituting (1.3) and (1.4) into (1.5)
[1.6] (j + k)m u_k= (j + k - 1)m SQRT(u_(k-1)^2+ 2gh)

Solving for the initial velocity u_k

[1.7] u_k=(j + k - 1)/(j + k) SQRT(u_(k-1)^2+2gh)

Which is a recurrence equation with base value

[1.8] u_0=0

The WTC towers were 417 meters tall and had 110 floors. Tower 1 began
collapsing on the 93rd floor. Making substitutions N=93, j=17 , g=9.8
into (1.2) and (1.7) gives

[1.9] WTC 1 Collapse Time = sum(k=0)^93 (-u_k+(u_k^2+74.28))/9.8 =
11.38 sec
where
u_k=(16+ k)/(17+ k ) SQRT(u_(k-1)^2+74.28) ;/ u_0=0

Tower 2 began collapsing on the 77th floor. Making substitutions N=77,
j=33 , g=9.8 into (1.2) and (1.7) gives

[1.10] WTC 2 Collapse Time =sum(k=0)^77 (-u_k+(u_k^2+74.28))/9.8 =
9.48 sec
Where
u_k=(32+k)/(33+k) SQRT(u_(k-1)^2+74.28) ;/ u_0=0

REFERENCES

"Seismic Waves Generated By Aircraft Impacts and Building Collapses at

This function returns the gravitational field strength in SI units.
g :: Double
g = 9.8

This function calculates the total time for a top-down demolition.
Parameters:
_H - the total height of building
_N - the number of floors in building
_J - the floor number which initiated the top-down cascade (the 0'th
floor being the ground floor)

cascadeTime :: Double -> Double -> Double -> Double
cascadeTime _H _N _J = sum [ (- (u k) + sqrt( (u k)^2 + 2*g*h))/g | k<-[0..n]]
where
j = _N - _J
n = _N - j
h = _H/_N
u 0 = 0
u k = (j + k - 1)/(j + k) * sqrt( (u (k-1))^2 + 2*g*h )

Simulates a top-down demolition of WTC 1 in SI units.
wtc1 :: Double
wtc1 = cascadeTime 417 110 93

Simulates a top-down demolition of WTC 2 in SI units.
wtc2 :: Double
wtc2 = cascadeTime 417 110 77

By Herman Schoenfeld

J

#### Janitor of Lunacy

accurately accounts for the collapse times of the World Trade Center

This was bollocks two months ago, and it's bollocks now. **** off.

I

#### Ishtar

accurately accounts for the collapse times of the World Trade Center
towers.

===========================

This is of no importance.

The ruling group are not doing it to us.
We are doing it all to ourselves.
We created the ruling group from our collective mental illness.

"Exposing corruption in the ruling group" is actually a case of
exposing our collective mental illness.

Your survivalist-mode mass scotoma conceals that simple truth from
your thought processes at this time.

We have a collective death wish, which includes a wish to revert to
full-scale dictatorship worldwide, because reversion to a state of
worldwide survivalist emergency, full-scale dictatorship, and inter-
tribal war for limited resources, including large-scale collective
vampirism and cannibalism without consent - all that is *associated in
our brains and in our archetypes with physical survival* , and so we
are in the process of arranging to re-enact our ancient history in
that way....

You ain't seen nothing yet, lads.....

-Pete
"The Trilogy of Truth"
http://www.network54.com/Forum/5746...ast-1190391729/THE+TRILOGY+OF+TRUTH+revisited

S

#### Shaun

accurately accounts for the collapse times of the World Trade Center
towers. A top-down controlled demolition can be simply characterized
as a "pancake collapse" of a building missing its support columns.
This demolition profile requires that the support columns holding a
floor be destroyed just before that floor is collided with by the
upper falling masses. The net effect is a pancake-style collapse at
near free fall speed.
It was really skilled of the pilots to crash just above the floors the
explosives were planted, in order to make it look like the collapse
was caused by the massive structural damage of having a large jets fly
into them

K

#### Kenny McCormack

Gotta love the list of groups to which this is cross-posted...!
And it was truly amazing how stealthfuly the demolition experts were
while they were working for weeks on end to place the explosives in
extacly the right places while there were 10,000+ people coming and
going on a daily basis.

This is just flat out wrong. First of all, modern office buildings
always have armies of "building types" (janitors, workers, whatever you
want to call them) coming and going all the time, doing "g*d knows what".

At night (i.e., basically, after about 5:30) they're pretty much the
only ones there, and they seem to wander the halls at will. I've often
wondered just what it is they do, seemingly all night long (I work late
hours myself and thus have opportunities to observe them).
Get a life you conspiracy theory nut-job.

No comment.

S

#### Spmbstr

accurately accounts for the collapse times of the World Trade Center
towers. A top-down controlled demolition can be simply characterized
as a "pancake collapse" of a building missing its support columns.
This demolition profile requires that the support columns holding a
floor be destroyed just before that floor is collided with by the
upper falling masses. The net effect is a pancake-style collapse at
near free fall speed.

This model predicts a WTC 1 collapse time of 11.38 seconds, and a WTC
2 collapse time of 9.48 seconds. Those times accurately match the
seismographic data of those events.1 Refer to equations (1.9) and
(1.10) for details.

It should be noted that this model differs massively from the "natural
pancake collapse" in that the geometrical composition of the structure
is not considered (as it is physically destroyed). A natural pancake
collapse features a diminishing velocity rapidly approaching rest due
the resistance offered by the columns and surrounding "steel mesh".

DEMOLITION MODEL

A top-down controlled demolition of a building is considered as
follows

1. An initial block of j floors commences to free fall.

2. The floor below the collapsing block has its support
structures
disabled just prior the collision with the block.

3. The collapsing block merges with the momentarily levitating
floor,
increases in mass, decreases in velocity (but preserves momentum), and
continues to free fall.

4. If not at ground floor, goto step 2.

Let j be the number of floors in the initial set of collapsing floors.
Let N be the number of remaining floors to collapse.
Let h be the average floor height.
Let g be the gravitational field strength at ground-level.
Let T be the total collapse time.

Using the elementary motion equation

distance = (initial velocity) * time + 1/2 * acceleration * time^2

We solve for the time taken by the k'th floor to free fall the height
of one floor

[1.1] t_k=(-u_k+(u_k^2+2gh))/g

where u_k is the initial velocity of the k'th collapsing floor.

The total collapse time is the sum of the N individual free fall times

[1.2] T = sum(k=0)^N (-u_k+(u_k^2+2gh))/g

Now the mass of the k'th floor at the point of collapse is the mass of
itself (m) plus the mass of all the floors collapsed before it (k-1)m
plus the mass on the initial collapsing block jm.

[1.3] m_k=m+(k-1)m+jm =(j+k)m

If we let u_k denote the initial velocity of the k'th collapsing
floor, the final velocity reached by that floor prior to collision
with its below floor is

[1.4] v_k=SQRT(u_k^2+2gh)

which follows from the elementary equation of motion

(final velocity)^2 = (initial velocity)^2 + 2 * (acceleration) *
(distance)

Conservation of momentum demands that the initial momentum of the k'th
floor equal the final momemtum of the (k-1)'th floor.

[1.5] m_k u_k = m_(k-1) v_(k-1)

Substituting (1.3) and (1.4) into (1.5)
[1.6] (j + k)m u_k= (j + k - 1)m SQRT(u_(k-1)^2+ 2gh)

Solving for the initial velocity u_k

[1.7] u_k=(j + k - 1)/(j + k) SQRT(u_(k-1)^2+2gh)

Which is a recurrence equation with base value

[1.8] u_0=0

The WTC towers were 417 meters tall and had 110 floors. Tower 1 began
collapsing on the 93rd floor. Making substitutions N=93, j=17 , g=9.8
into (1.2) and (1.7) gives

[1.9] WTC 1 Collapse Time = sum(k=0)^93
(-u_k+(u_k^2+74.28))/9.8 =
11.38 sec
where
u_k=(16+ k)/(17+ k ) SQRT(u_(k-1)^2+74.28) ;/
u_0=0

Tower 2 began collapsing on the 77th floor. Making substitutions N=77,
j=33 , g=9.8 into (1.2) and (1.7) gives

[1.10] WTC 2 Collapse Time =sum(k=0)^77
(-u_k+(u_k^2+74.28))/9.8 =
9.48 sec
Where
u_k=(32+k)/(33+k) SQRT(u_(k-1)^2+74.28) ;/ u_0=0

REFERENCES

"Seismic Waves Generated By Aircraft Impacts and Building Collapses at
http://www.ldeo.columbia.edu/LCSN/Eq/20010911_WTC/WTC_LDEO_KIM.pdf

This function returns the gravitational field strength in SI units.
g :: Double
g = 9.8

This function calculates the total time for a top-down demolition.
Parameters:
_H - the total height of building
_N - the number of floors in building
_J - the floor number which initiated the top-down cascade (the 0'th
floor being the ground floor)

cascadeTime :: Double -> Double -> Double -> Double
cascadeTime _H _N _J = sum [ (- (u k) + sqrt( (u k)^2 + 2*g*h))/g |
k<-[0..n]]
where
j = _N - _J
n = _N - j
h = _H/_N
u 0 = 0
u k = (j + k - 1)/(j + k) * sqrt( (u (k-1))^2
+ 2*g*h )
[Spam]

Simulates a top-down demolition of WTC 1 in SI units.
wtc1 :: Double
wtc1 = cascadeTime 417 110 93

Simulates a top-down demolition of WTC 2 in SI units.
wtc2 :: Double
wtc2 = cascadeTime 417 110 77

By Herman Schoenfeld

J

#### Joachim Schmitz

Spmbstr said:
news:[email protected]:
<needless fullquote of garbage snipped>

Could you please stop this nonsense? Spam is bad enough, its repition even
worse.

G

#### Guest

... it was truly amazing how stealthfuly the demolition experts were
while they were working for weeks on end to place the explosives in
extacly the right places while there were 10,000+ people coming and
going on a daily basis.

You mean the Securicom guys who worked for Marvin P. Bush?

Nick

K

#### Kenny McCormack

<needless fullquote of garbage snipped>

Could you please stop this nonsense? Spam is bad enough, its repition even
worse.

You just don't get it. This guy *is* performing a service. It is up to

I won't bore you further with details; you can (it is hoped) figure the

J

#### Joachim Schmitz

Kenny said:
You just don't get it.
You sound as if you had told me several times already. You have not, so
This guy *is* performing a service. It is up
This guy is replicating spam, is that the service you're referring to?
Well, me too, only that I ask him to stop that 'service'.
I won't bore you further with details; you can (it is hoped) figure
the rest out on your own.
The only thing I can do is to configure my newsreader to ignore articles
with a Subject of "[Spam]" or originating from a User that goers by the name
of "Spmbstr", which I wouldn't need if these wouldn't exist and it does not
prevent me from seeing the orginal spam article, hadn't my provider been
kind enough to delete or hide if for me.

When I see it I can verywell tell spam from non-span, so I don't need
someone else telling me. And repeating the whole junk makes it even worse.

R

#### Richard

Joachim Schmitz said:
You sound as if you had told me several times already. You have not, so

This guy is replicating spam, is that the service you're referring to?
Well, me too, only that I ask him to stop that 'service'.

Are you really so naive as to think he will listen to you? Killfile
him. if that does not work, do NOT reply to him. You only bring the post
to the attention of those of us who have filtered these guys already
otherwise. You're a decent poster - please don't go the "Chuck" route
and think that everyone listens to you admonishing naughty posters.

D

#### Default User

Joachim said:
Kenny McCormack wrote:

[blah blah]
When I see it I can verywell tell spam from non-span, so I don't need
someone else telling me.

Now work on telling the trolls from the human beings. (Hint, Kenny is a
troll).

Brian

R

#### Ross A. Finlayson

Janitor said:
This was bollocks two months ago, and it's bollocks now. **** off.

Yeah it was bollocks seven years ago too.

http://www.ae911truth.org/info/24

"Undisputed Facts Point to the Controlled Demolition of WTC 7", why?

http://wtc.nist.gov/media/JonesWTC911SciMethod.pdf

Wargames, plane crashes into the building "drills", FEMA setup in NYC,
post-faked timelines on 9/11, why?

Evidence from the WTC site and crash sites are gone, i.e. unavailable to
chemical analysis, small samples illustrate metal spallation along the
lines of thermite reaction, why?

"Ground Zero", why?

Why?

Basically later to be considered a false flag operation, 9/11 shall go
down in history as a massiave failure of representative democracy.

Death to terrorists! I'm for mass hangings of terrorists, those who
terrorism, affect your polotical aims! Death to terrorists! Death to
spies!

That's what the Constitution, of the USA, says.

As a firm believer in the rights of the mostly Bill of Rightsn of the
Constitution whereby it was adopted, according to the framers, it's time
to clean house.

Hell, it's been a long time since it was time to take the criminals out
of the USA and make the USA good again, taking the criminals away and
punishing them.

http://www.amazon.com/Punisher-Vol-Welcome-Back-Frank/dp/0785107835

Welcome back, Frank.

Thanks,

Ross