Date: Mon, 17 Sep 2001 08:14:55 -0400

Author: Angela Plagemann

Subject: RE: Final ''off topic'' thoughts about last week


On Tuesday, Sept. 11, during the day, CNN found one of the architects that
had designed the World Trade Center. He said that they had designed the
buildings to withstand whatever Mother Nature could dish out (earthquake,
storm, tornado, etc.), but they did not design it for an airplane crash.
His explanation of the collapse was that both towers have a central steel
core that holds them up. The steel core was designed to withstand high heat
for about 1-2 hours, with the assumption that by then the fire could be put
out and all would be well. The buildings did exactly as they were designed
to do. They withstood the heat for about 1-2 hours and then the central
core melted, unfortunately causing the building to collapse. In hindsight,
as I was watching this interview, I could only wonder why these architects
did not think of this sooner and warn the firefighters and other rescue
workers that the core would melt in that amount of time.

Angela Plagemann
Demonstration Lab
Physics Department
University of Michigan
(734) 936-2498

> -----Original Message-----
> From:
> []On Behalf Of Earl Dolnick
> Sent: Saturday, September 15, 2001 23:57
> To:
> Subject: Re: Final ''off topic'' thoughts about last week
> OK, so let's bring in back to physics. Why did the buildings
> collapse? The
> top of Tower 2 started to lean, and I half expected the building to break
> at that point, but the complete structure seemed to give way from the top
> down. And I was even more surprised, when I got to work that morning, to
> learn that Tower one, the first one hit also collapsed. I'm not
> much of an
> ME. Anyone have ideas?
> Peace Earl D.
> At 12:09 PM 9/15/01 +0200, you wrote:
> >Martin,
> >
> >Ay, ay Sir, I very much agree with you. Let us stick to physics
> which means
> >looking at things in a rational and profound way. No religion here.
> >
> >Take care all of you wherever you are.
> >
> >Urs
> >
> > >At 08:29 PM 9/14/01 -0500, Andrew Yue wrote:
> > >
> > >>I'll make my reply off Tap-L since it may sound like a
> political speech or
> > >>in this case a call to war.
> > >
> > >Well, Andrew, your note did go out to Tap-L. I would ask
> everyone to stay
> > >on topic
> > >even if the list operates at a reduced level. Some other
> lists I'm on have
> > >degenerated
> > >into personal attacks and petty arguments over the current
> situation, and
> > >I'm sure that
> > >we don't want to go in that direction. There are many other forums for
> > >such discussions
> > >and activities but only one Tap-L.
> > >
> > >Best wishes,
> > >
> > >Martin Simon
> >