Analysis of WTC 1 and 2 Collapse Times

Many of you may recall reading the following collapse time analysis by Jim Hoffman.

When I came upon this analysis again recently I noticed that he explains an apparent three second disparity between one possible interpretation of seismic evidence and the video evidence as an error. But what if there wasn't a disparity at all?

Mr. Hoffman states, "Video recordings show that the rubble started to reach the ground about 12 seconds after the start of the destruction." The beginning of the collapse of WTC1 was 10:28:22 as determined by NIST from video evidence. Also found in their report is information regarding a more recent analysis of the seismic data which gives the time for the onset of the seismic event related to the collapse of WTC1 as 10:28:34 - twelve seconds after the start of the collapse.

Duration of the seismic events is available from the LDEO website. The North Tower collapse event lasted about 8 seconds. Adding this to the onset time given above would result in an end time for the seismic event of 10:28:42 am.

Therefore, using this method, the duration of the WTC1 collapse is approximately 20 seconds. (10:28:22 to 10:28:42) The margin of error would likely be ±3 seconds.

Extending this method to the South tower, the beginning of the collapse determined by NIST is 9:58:59, the beginning of the seismic event given in their report is 9:59:07 and the duration as reported by LDEO was 10 seconds.

Therefore, using this method, the duration of the WTC2 collapse is approximately 18 seconds. (9:58:59 to 9:59:17) The margin of error would be the same as for the North Tower.

Does this method of calculating the collapse times give better approximations of the actual times than making an estimate from videos that have the ends of the collapses obscured by clouds of dust?

- Make7


Sources:

http://www.ldeo.columbia.edu/LCSN/Eq/20010911_wtc.html

http://wtc.nist.gov/NISTNCSTAR1-5A_chap_1-8.pdf  (pdf page 118)
DIAL-UP USER WARNING: The link above is to an extremely large file. I have no idea how long it may take to open.
 

the laws of physics were suspended and the acceleration due to gravity was much less around Ground Zero.

Proves the use of an anti-gravity beam weapon. :freak:

is within the definition of "nearly freefall?" for CT'ers

Any CT'er care to comment?

If you factor in Anti-Gravitons. :crazy:

regarding the fall of the buildings?

:popcorn:

The impacts of the planes caused structural damage to the towers and also dislodged some of the spray on fire proofing of steel members. The fires started by the fuel from the impacts of the planes and fed by the contents of the buildings caused weakening of some of the structural elements of the towers. This led to the sagging of portions of some floors which caused the inward bowing of numerous perimeter columns. The subsequent buckling of these perimeter columns initiated the collapse of each respective tower. Global progressive collapse followed due to the inability of the remaining structure to redistribute the loads without also failing.

A more detailed explanation can be found at the following link:

    http://wtc.nist.gov/reports_october05.htm

- Make7

Much appreciated - just too much to read right now & no time.