Originally Posted by Andrew Johnson in Sept 2004
There is a simple observation and calculation that can be made. The Twin Towers collapsed in about 8 & 10 seconds respectively, top to bottom (ground level). They were 1350 feet high (source: Groliers Multimedia Encyclopedia, 2000 edition) – let’s approximate to 1300 feet high.
Now, as we know: from the Law of Falling Bodies and the Laws of Motion, described by Galileo and Isaac Newton over 300 years ago.
or if u=0,
Rearranging for t gives:
So, for a ball bearing dropped from the top of the towers, it would drop 400m (=1300ft). In the expression above, therefore, s = 400m. In the equation above, a is actually the acceleration due to gravity = 9.81 m/s2. These are all checkable facts – consult a physics textbook or encyclopedia.
So, the time taken for ball bearing free-fall =
Therefore, the towers came down with almost NO RESISTANCE. That means that, when the planes hit, IT MUST HAVE STARTED A CHEMICAL/CHAIN REACTION which caused *ALL* THE STEEL GIRDERS THROUGHOUT THE BUILDING to VAPORISE after a few minutes! This is clearly a fallacy! The heat of a kerosene-fuelled fire simply could not have caused this type of reaction. All other skyscrapers that have had fires – sometimes burning for hours – have not even come close to collapsing. Another checkable fact – Kerosene burns at a maximum temperature of about 1500°F (816°C). Steel melts at approximately 2700°F (1482°C). Other evidence at the site of the disaster also leads one to the conclusion that the Steel columns in the towers were destroyed with something like C4 explosives, which would generate enough heat to melt the steel, so that the towers underwent a freefall collapse. Think about it – even the columns in the lower sections of the building were completely destroyed, where there was no fire!
This must be correct because one of the towers collapsed in about 8 seconds – i.e. the vacuum created by the demolition explosives "sucked the building down" slightly, reducing the collapse time. This analysis, should, of course be on every news bulletin – but as ever, few people are thinking and listening.
(The figures for the collapse time are slightly different in the PowerPoint slides because I used a height of 1350 feet rather than 1300 feet)
for a more complete analysis of this line of thinking, please view