If you watch the following video closely, you will notice a plume just above the sky lobby and below the point of impact before the tower begins to fall. Pause the video at the :01 second mark...

http://www.youtube.com/watch?v=XNmJZUQD74s

Remember, if these plumes originate from explosives placed around the core, there would be a split second time delay between the moment of detonation and appearance of squibs.

Explosive demolition folks!

In the NBC video taken of the South Tower collapse, a small white squib emerges from the level of the impact zone (0:02 seconds) about three-quarters of the way back on the right face. This immediately precedes the first large ejections from the southeast face.

http://www.911research.com/wtc/evidence/vi...r_collapse.mpeg

Forget that.

Prove the use of explosives with Newton's first law.

We all believe the collapse of the South Tower due to having seen the videos of the collapse so much - the video forces the observer to think with their eyes, not their brain. It's really quite fascinating.

Thought Experiment:
If you remove all the rubble and debris, you wind up with a 110 some story building with the approx. top 1/3rd sitting at an angle. Now, apply Newton's first law.

The center of gravity of the tilted portion is no longer directly above the core. The core is the main object of the bottom 2/3rds that offers resistance.

Air is less resistant than the core of the building, ergo the top portion should have tumbled off the building onto the street.

I have other theories on this matter which I am also investingating.