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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
Other Major 9-11 Photo Archives
The 911Dataset Project

WTC Structural Information

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Online Misrepresentations of the WTC Collapses

Forum, Blog Representations of the WTC Collapses

The Book Tested Through Experiments

Miscellaneous Notes, Resources
FAQ for Miscellaneous Notes
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

Jolts detected in early NW corner, antenna drop

Jolts detected in early NW corner, antenna drop

Antenna and NW Corner Drop Curves: The Detection of Jolts

Drop curves of a point on the antenna and a point on the NW corner, Sauret viewpoint

The Sauret drop curve of the NW corner is shown in blue. Its corresponding velocity curve is shown in purple. The drop curve of a point on the antenna is shown in yellow. Its corresponding velocity curve is shown in green.

If the 2 points were part of a "rigid block" rotating about an axis over the first few degrees of tilt, both the slopes and the curvatures of the position data at any moment would remain proportional to one another. They clearly do not.

There is no relation between slope or curvature between the two positional data plots. Instead they move quite independently, telling us that there is no fixed "rigid block" motion.

Notice the antenna drops about 2 ft slowly (before it has any significant velocity). This is easy to see by looking for the failure point, or release event of each curve and studying the pre-release movement as described below:


First, locate the release event. In some frame the velocity will begin to take off, meaning the slope of the velocity plot changes quickly. This is because there is an abrupt change in acceleration. This frame can be called the "release event" or "release moment".

Second, separate the curve into 3 regions: A pre-release region, a post-release region and the region of the release event.

Pre-release motion could be drift, creep. deformation, tilting, vibration or any slower movement which lacks a downward acceleration at a significant percent of g. A careful researcher should trace points in the pre-release region as far back as necessary to discover the earliest motion possible.

Post-release motion has an average downward acceleration of 0.5g to 1.0g. It may have moments of velocity reductions or may not. If so, the momentary downward acceleration between reductions may differ from the average acceleration and should be considered separately. Locations and magnitudes of the velocity reductions may provide valuable information about what is really happening inside the building over the first 12 feet of falling.

The release event Using the velocity graph, curvature at the release point may help determine how quickly the initial failure occurred.

Application of this approach to the Sauret antenna and NW corner drop curves:

We see there is an abrupt change in the slope of the velocity curve that can be traced back to around frame 222. This is the release event for the NW corner, the first moments in which downward velocity noticeably takes off.

The acceleration (slope of the velocity curve) quickly changes through frame 222. The traced point is now falling at 0.5g to 1.0g. There is one measured velocity reduction around frame 250. In frame 250 the positional data shows the NW corner has fallen about 3 ft.

In the pre-release region we can carefully study changes in the positional data as far ahead of frame 222 as we wish, looking for the earliest detectable deformations.

The Sauret drop curve of the black-white transition point on the antenna is in yellow. It's corresponding velocity curve is in light green. We see movement from frame 140, yet the velocity curve does not take off with a 0.5g to 1.0g acceleration until frame 215. The release event is around frame 215.

In the pre-release region we see considerable movement before frame 215. Over 2 feet of downward displacement is measure in the antenna between frames 130 and 215.

In the post-release region we detect one velocity reduction. How far has the traced point dropped when the reduction occurs? It happens around frame 228, when the positional data shows a 3 ft drop.

Detection of velocity reductions in both the antenna and NW corner drop curves.

Notice that both the antenna and NW corner experience a measurable velocity reduction after about a 3 ft downward displacement. It is quite interesting that there is a time interval between the velocity reduction on the antenna and the one for the NW corner, a slight delay between the the reductions, the antenna leading the NW corner by about 20 frames, or 0.3 seconds.

NW CORNER DROP AND VELOCITY CURVE: Independent confirmation of velocity reductions

In a separate set of measurements, the position drop curve of the NW corner (the smooth curve) is shown below


Below it the slope of the curve, representing velocity, is plotted. Notice the 3 distinct velocity reductions marked by the green lines.

The reductions along the NW corner seem to occur after a 3 ft, 7 ft and 16 ft drop.

Here is a close-up of the NW corner failing over the first 12 ft:

An excellent clip that allows us to see the NW corner during the initial failure and the first 12 ft of falling:

Link to the discussion showing how these two curves were derived is here:

Created on 10/12/2010 05:09 AM by admin
Updated on 07/27/2013 01:00 PM by admin
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