9/11

[Holdem]

"- Before the collapse, there was thick black smoke coming out of the towers. This means that the fire is burning out due to lack of oxygen."

The thick, black smoke you see is not a fire about to burn out. That's a Bravo-class fire (flammable liquids, IE: Jet fuel, kerosene, etc.).
[Image: fire-control-1.jpg]

Grade-A jet fuel burns at around 980 C. The temperature at which the bonds in steel shift is around 702.5 C. It's a phase change from cementite and pearlite (strong phases of steel) to austenite (significantly less strong). The structure of the tower wouldn't need to melt for the building to collapse on itself. The open flames that you see wouldn't have to be white-hot.

Also mind that 4-inch knives were permitted through airports pre-9/11, and those were the ones used against the crews of the airliners.

1535ºC (2795ºF) - melting point of iron
~1510ºC (2750ºF) - melting point of typical structural steel
~825ºC (1517ºF) - maximum temperature of hydrocarbon fires burning in the atmosphere without pressurization or pre-heating (premixed fuel and air - blue flame)
Diffuse flames burn far cooler.
Oxygen-starved diffuse flames are cooler yet.

The fires in the towers were diffuse -- well below 800ºC.
Their dark smoke showed they were oxygen-starved -- particularly in the South Tower.

I would like for you to explain why you could see steel melting from the towers if the temperature was nowhere close steel/iron melting temperature.

Also, please explain what caused the third world trade centre to collapse if there was hardly any fire at all.

Here are the fires at the WTC 7 (Third WTC that collapsed)

[Image: wtc7_nypd2001.jpg]

Here are other fires in steel buildings.

[Image: 12447454a26a3309fa.jpg]

[Image: Flame-Engulfed-Steel-Frame-High-Rise-Bui...llapse.jpg]