I have revisited and extended some of my early measurements of high speed massive projectiles from the World Trade Center on 9/11. The results for the three projectiles measured: 56 mi/hr, 45 mi/hr, and 78 mi/hr. I don't claim this is smoking-gun evidence of explosive demolition all by itself, but it is part of the puzzle and it is more compatible with the explosive demolition hypothesis than simple gravitational collapse.
High Speed Massive Projectiles from the WTC on 9/11
We are told that the Twin Towers of the World Trade Center were weakened by airplane impacts and fire, then came down in a gravity-driven collapse.
Just look at the supposed collapses. It stretches credibility to even call them collapses. These events resemble explosions, even eruptions, more than collapses. We are not seeing the walls come a tumblin' down, with the dust blown out to the side. We are seeing massive projectiles thrown horizontally hundreds of feet.
My very first personal investigation of the 9/11 events was when I watched the expanding debris cloud from the North Tower on a DVD several years ago. I paused the DVD, took out a ruler, and estimated horizontal velocity of one of the debris streamers right on the television screen. My rough estimate was about 60 miles per hour. With that measurement, I was hooked. I realized something very strange was going on.
First, I looked at the westward moving projectile from the North Tower that I had crudely measured on the television screen a few years ago. This time, I got a reliable value of 25 meters per second, which translates to about 56 miles per hour. My original estimate was pretty close.
Another high-speed projectile was launched northward from the North Tower, late in the collapse, toward Building 7. Closeups show the structure of the object which appears to be one or more wall units. This particular video footage was shot by Rick Siegel from across the Hudson River. He panned the camera a lot so the measurement was a challenge. But I decomposed the video into individual images and manually aligned the images to stabilize the video. I used the stabilized video to do the measurements and got good uniform results: 35 meters per second or 78 miles per hour. I've repeated this measurement with other techniques and have consistently gotten results well over 70 miles per hour.
High-speed massive horizontal projectiles may not be smoking gun evidence all by itself, but it is very suggestive of an explosive event. It's another piece of the puzzle.
(On a technical note, if you are looking at the numbers in the three measurements, the third measurement is taken while the video was zoomed in, relative to the calibration frame. The numbers shown have to be scaled down by a factor of 1.701 to give the stated results.)