Chronic Logic

Hi,

On purchasing on this fabulous software I set out trying to see if Pontiflex's physics engine can replicate the tragedy.

I began by creating a new level and making four anchor points. I extended the budget to � and set about building up and up creating the same (sort of) structure that the WTC 1 building consisted off.

It had two main lift shafts with a criss cross infrastructure.

Once I had built a replicate I removed the parts that the plane would have destroyed.

Anticipating pressing the test button and letting the physics engine do its work I wondered if my machine:

P4 1.8GHz
1GB RAM
60GB Hdd
nVidia Ti200 64MB DDR

would handle the instructions. To my dismay Pontifex removed all of the links and only displayed 3-4 structures falling from the sky.

My question is:

Can Pontifex handle this huge task even although it was not designed for it?

Why did it display only afew structures when the original plan contained hundreds?

I would insert a screenshot if I could, but I cant for some unknown reason.

if you criss-cross too much, it'll implode.  known bug.

Thanks Calastigro.

I do not want to appear sadistic about this test. My full respect is given to all those who lost loved ones in this terrible tradegy, we unite in sorrow.

Regards,

Neil
Scotland U.K.

The WTC did not have a criss cross infrastructure; rather the outer steel walls formed a sort of hollow tube that protected against vibration and wind sway.

You can read more on this (plus see some links) in the Bridge Builder Forums, in this thread (click!).

Against war and terror in all shape or form,
mendel

(Edited by mendel at 2:21 am on Mar. 7, 2002)

Your comment on the outer steel tube is right.  Although pierced by thousands of 'small' openings for light, the external steel skin was the only structural element maintaining stability against lateral forces (primarily wind - but in this tragic case, airplane impact).  The central core was not able to support anything but vertical loads and was braced against buckling by the lateral restraint of the floor trusses.

Once the floor trusses failed (as a result of fire primarily) the central core (also weakened by fire) buckled and allowed the upper floors to collapse.  Once in motion, there was little that could have been done to ever stop the whole lot coming down.

actually the plane going trough smashed the inner core and the outer shell(tube) was what kept it up.. the intese fire (all the gasoline) didnt melt but weakened the outer beams enouight that they buckeled.. since the middle core was "missing" the core in the above floors fell down on the core below the hole and the weight of THAT push made the towers collaps like a deck of cards.... major bummer.. ;(

well thats how my physics teacher xplained it to me.. i guess theres like 40 billion reasons it went like it did.. no gasoline would have left it remained standing..

(Edited by orealis at 6:02 pm on April 10, 2002)