(03-21-2021, 02:38 AM)Mav date Wrote:I wonder whether there were conspiracy theories floating around after the Challenger Space Shuttle blew up. The Russians had a motive to cripple the US Space program as did the Europeans as they were involved in launching satellites via their Ariadne rockets. Could the official explanation of degraded O-rings really explain the explosion when there had been numerous successful launches without any problem in that regard?

(03-21-2021, 02:09 AM)Baggers link Wrote:If you check out the footage you'll see the fire in building 7 was contained to one specific area... yet the entire building collapsed uniformly.

Again, I don't offer any explanation other than the official versions do not stack up... and that leads folks, as Wing Man Mav might say, heading down all kinds of 'rabbit holes' and emerging with some 'tantalizing' theories to feed the vulnerable.

Quote:4. What caused the fires in WTC 7?

Debris from the collapse of WTC 1, which was 370 feet to the south, ignited fires on at least 10 floors in the building at its south and west faces. However, only the fires on some of the lower floors—7 through 9 and 11 through 13—burned out of control. These lower-floor fires—which spread and grew because the water supply to the automatic sprinkler system for these floors had failed—were similar to building fires experienced in other tall buildings. The primary and backup water supply to the sprinkler systems for the lower floors relied on the city's water supply, whose lines were damaged by the collapse of WTC 1 and WTC 2. These uncontrolled lower-floor fires eventually spread to the northeast part of WTC 7, where the building's collapse began.

5. How did the fires cause WTC 7 to collapse?

The heat from the uncontrolled fires caused steel floor beams and girders to thermally expand, leading to a chain of events that caused a key structural column to fail. The failure of this structural column then initiated a fire-induced progressive collapse of the entire building.

According to the report's probable collapse sequence, heat from the uncontrolled fires caused thermal expansion of the steel beams on the lower floors of the east side of WTC 7, damaging the floor framing on multiple floors.

Eventually, a girder on Floor 13 lost its connection to a critical column, Column 79, that provided support for the long floor spans on the east side of the building (see Diagram 1). The displaced girder and other local fire-induced damage caused Floor 13 to collapse, beginning a cascade of floor failures down to the 5th floor. Many of these floors had already been at least partially weakened by the fires in the vicinity of Column 79. This collapse of floors left Column 79 insufficiently supported in the east-west direction over nine stories.

https://www.nist.gov/topics/disaster-failure-studies/faqs-nist-wtc-7-investigation

(03-21-2021, 04:07 AM)DJC date Wrote:Check out the FAQs on the National Institute of Standards and Technology website:

(03-21-2021, 02:38 AM)Mav link Wrote:I wonder whether there were conspiracy theories floating around after the Challenger Space Shuttle blew up. The Russians had a motive to cripple the US Space program as did the Europeans as they were involved in launching satellites via their Ariadne rockets. Could the official explanation of degraded O-rings really explain the explosion when there had been numerous successful launches without any problem in that regard?

(03-21-2021, 01:28 AM)northernblue link Wrote:How many individual buildings have had 767’s deliberately crashed into them ?

(03-20-2021, 12:18 PM)LP link Wrote:I doubt I'll get anything about physics, materials or engineering from it.

(03-21-2021, 04:57 AM)kruddler date Wrote:I'm not sure of the answer, but i know there are at least 3 other buildings that have been crashed into by planes and survived....easily.

Technically, you could add the 2 WTC's into that too, because planes didn't bring them down either.