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Why Fact-check? Why preserve a visual record?

The Website Written as a Book
1: Science and Subjective Viewpoints
2: Toward Accurate Collapse Histories
....2.1: Progressive Floor Collapses in the WTC Towers
....2.2: General Global Characteristics of Collapses
....2.3: Mathematical Basis of ROOSD Propagation
....2.4: WTC1 Accurate Collapse History
....2.5: WTC2 Accurate Collapse History
....2.6: WTC7 Accurate Collapse History
3: WTC Collapse Misrepresentations
....3.1: Purpose of the NIST Reports
....3.2: NIST WTC1 Misrepresentations
....3.3: NIST WTC7 Misrepresentations
....3.4: NIST WTC2 Misrepresentations
....3.5: Reviewing the Purpose of NIST and FEMA Reports
....3.6: Bazant Misrepresentation of Collapse Progressions
....3.7: Block Misrepresentations of Collapse Progressions
....3.8: AE911T Misrepresentations of the Collapses
4: Scientific Institutions Can Be Unaware of Contradiction
5: Reassessing the Question of Demolition
....5.1: The Case of WTC1
....5.2: The Case of WTC2
....5.3: The Case of WTC7
6: WTC Collapse Records Studied as Meme Replication
....6.1: Meme Replication in Technical Literature
....6.2: Meme Replication in Mass Media
....6.3: Meme Replication in Popular Culture
....6.4: John Q Public and the WTC Collapse Records

WTC Twin Towers Collapse Dynamics

Official, Legal Attempts to Explain Collapses

Academic Attempts to Explain Collapses Reviewed

On the Limits of Science and Technology

WTC Video Record

WTC Photographic Record
WTC1 Attack to Collapse
WTC2 Attack to Collapse
Fire Progression, WTC1 North Face
Fire Progression, WTC1 South Face
Fire Progression, WTC1 East Face
Fire Progression, WTC1 West Face
Fire Progression, WTC2 North Face
Fire Progression, WTC2 South Face
Fire Progression, WTC2 East Face
Fire Progression, WTC2 West Face
Debris: WTC1 Around Footprint
Debris: WTC2 Around Footprint
Debris: From WTC1 Westward
Debris: From WTC1 Northward
Debris: From WTC2 Eastward
Debris: From WTC2 Southward
Debris: Plaza Area, Northeast Complex
Debris: Hilton Hotel, Southwest Complex
Debris: General, Unidentified Locations
Damage to Surrounding Buildings
Perimeter Column Photo Record
Perimeter Columns: Types of Damage
Core Box Columns: Types of Damage
Complete Photo Archive
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The 911Dataset Project

WTC Structural Information

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Online Misrepresentations of the WTC Collapses

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Miscellaneous Notes, Resources
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History Commons 9/11 Timeline
The 911Dataset Project
Skyscraper Safety Campaign
First and Largest 9/11 Conspiracy Theory
Key Words in Book and Website
Trapped Within a Narrowed False Choice
Vulnerability and Requestioning
On Memes and Memetics
Obedience, Conformity and Mental Structure
Denial, Avoidance (Taboo) and Mental Structure
Taboos Against Reviewing the Collapse Events
Extreme Situations and Mental Structure
Suggestibility, Hypnosis and Mental Structure
Awareness and Behavior
Magical, Religious, Scientific Cause-Effect Relations
The Extreme Limits of Mental Dysfunction
Orwell's "Crimestop", "Doublethink", "Blackwhite"
William James, Max Born: Science as Philosophy
Plato on Self Reflection and Mental Structure
Rewriting History, part 1
Rewriting History, part 2
On Smart Idiots

New Ideas in Education

WTC1 Inward Bowing of the S Perimeter

WTC1 Inward Bowing of the S Perimeter

Inward bowing (IB) of the perimeter was observed on WTC1 and WTC2.

The best images I could find of the WTC1 south wall IB are linked here: (1200x1600px/179.7Kb) (1200x1600px/176.4Kb) (1200x1600px/187.0Kb) (1200x1600px/252.8Kb)

NIST measurements of inward bowing at about 10:22:

Time-line of the formation of WTC1 inward bowing along the south wall:

9:58 No fires are visible on the east side of the south perimeter. Only some smoke coming out of a few windows.

9:59 3 large fireballs emerge from the middle and east side of the south perimeter as WTC2 starts to collapse. These locations mark the center of where IB will be visible after a few more minutes. Two clips which highlight the ejections:

10:06 Southward leaning and IB are first reported

IB increases to a maximum measured 55 inches over 22 minutes (this would require about 9 feet of floor sagging to attain)

The NIST's own fire simulations do not provide excessive heat for the slabs to create such bowing as seen in this gif:

10:28 Building collapses. The NIST claims that floor sagging pulled in the south perimeter to the point of failure. The south wall failure overloads the core, causing progressive column failures from south to north over a tilt of 8 degrees.


In reality, all core and perimeter columns have failed with minimal tilt. both the antenna and north wall had tilted less than 1 degree during the entire column failure sequence. All columns have failed by this moment:

The range of tilt during the collapse initiation sequence is determined here

Perhaps the cause of the IB has more to do with the large fireballs that emerge from the center of the IB region only a few minutes before IB was first reported?

NIST mentions the fire ejections briefly:

NCSTAR1-5, Page 15: "Very shortly after the collapse began, fire and smoke were pushed out of the south face of WTC 1, probably due to a pressure pulse transmitted to WTC 1 from the collapsing tower. The most prominent effect was on the 98th floor where flames were pushed out of windows along the west side of the face."

Probably? It is not hard to verify this so why guess? There is smoke coming from the south face around this region and we can see no movement due to the collapsing tower within the smoke. Any wind pulse transmitted from WTC2 to WTC1 would be visible within movement of the veil of smoke covering the south wall of WTC2.

Also, the ejections come from the center and east side as anyone can see, not the west side.

Two Geometric Possibilities for Inward Bowing

NIST has a theory of what caused the IB, and their collapse initiation scenarios for both buildings depends upon it being correct.

The NIST description of WTC1 south wall inward bowing:

1-6D, pg 314:

"Bowing of South Wall

The exterior columns on the south wall bowed inward as they were subjected to high temperatures, pull-in forces from the floors beginning at 80 min, and additional gravity loads redistributed from the core. Figure 5"6 shows the observed and the estimated inward bowing of the south wall at 97 min after impact (10:23 a.m.). Since no bowing was observed on the south wall at 69 min (9:55 a.m.), as shown in Table 5"2, it is estimated that the south wall began to bow inward at around 80 min when the floors on the south side began to substantially sag. The inward bowing of the south wall increased with time due to continuing floor sagging and increased temperatures on the south wall as shown in Figs. 4"42 and 5"7. At 97 min (10:23 a.m.), the maximum bowing observed was about 55 in. (see Fig. 5"6).
55 inches of inward bowing (IB) requires about 9 ft of floor sagging. According to the NIST's own description of the event, the floors sagged about 9 ft between 9:06 and 9:23."

9 feet of floor sagging in 17 minutes is what the official story of collapse initiation depends upon. Make sense?

Great visual model of the extent of the sagging required to produce a 55 inch IB is shown by mmmlink:

Even worse, there was no visible fire on the east side of the south face until the 3 large fire ejections appeared at 9:59.
The ill-fated perimeter section in red is where the maximum measured inward bowing is observed only 24 minutes later.

It will be pulled in more than 4 ft in 24 minutes by the famous sagging floor trusses.

Then, that wall will rip the east and west perimeter and the core down while not causing any vertical feature to tilt more than 1 degree from plumb.

Created on 10/15/2010 12:05 PM by admin
Updated on 11/10/2014 07:55 AM by admin
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