Path: csiph.com!fu-berlin.de!uni-berlin.de!individual.net!not-for-mail From: Thomas Heger Newsgroups: sci.physics.relativity,sci.electronics.design Subject: Re: energy and mass Date: Fri, 27 Mar 2026 09:13:58 +0100 Lines: 75 Message-ID: References: <1rr4tn1.1w93c9h1iqg7fgN%nospam@de-ster.demon.nl> <10nupu0$3c2s4$3@dont-email.me> <10o12sp$3pb4$2@dont-email.me> <10o6ks6$20j6f$2@dont-email.me> <10oel9r$mo2r$1@dont-email.me> <10p5fb3$r5l9$5@dont-email.me> <10pdunt$3n2fa$5@dont-email.me> <10ph1ko$p89a$2@dont-email.me> <10pjqkv$1mlp8$3@dont-email.me> <10pojcn$380fj$1@dont-email.me> <10pr8a3$1db2$5@dont-email.me> <10q0fau$1r9os$4@dont-email.me> Mime-Version: 1.0 Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 8bit X-Trace: individual.net SPgjhYW4JAoehZktxcpM/A7VSBEMFmlUQ5oP3CTKOlVTKr2OGU Cancel-Lock: sha1:+S6OrIGKbZDadB+OZTcl0LVb9ec= sha256:dls+cYLPdkIcmHi0LYNBlCeWG5+/McctmWBC5RmUghQ= User-Agent: Mozilla Thunderbird Content-Language: de-DE In-Reply-To: Xref: csiph.com sci.physics.relativity:670514 sci.electronics.design:742345 Am Donnerstag000026, 26.03.2026 um 15:00 schrieb Thomas Heger: ... >>> So, material objects with a mass larger than 20 to of steel and >>> concrete 'dustified' in mid air and were blown away. >> >> They got broken up in a series of smaller collisions, as each floor >> fell onto the floor below it, and got further broken up by each impact >> in succession. > > That's not how things fall, if they hit something hard below. > > If you would drop something breakable from some hight upon something > breakable, but with high resistance against breaks, you would expect a > different pattern: > > the upper part of a collision would cause breaks in the parts below, but > also braks of the same kind in itself, because the both parts were > assumed to have the same strength. > > If we concentrate on the upper part only (for a moment), we would expect > parts of the falling piece to splinter off and fall partly outside of > the former building shape, hence would fall in free fall outside down to > the ground. > > Doesn't matter that much, what percentage would break of the upper part, > because at least some parts would do that. > > But even at the hight of the actual impact zones, sections of the > perimeter wall of the twintowers would fall down with enormous mass and > velocity. > > IoW: possibly you were right and not that many 'cannon balls' or 'fright > trains' would have hit the ground, but certainly some. > > But apparently this didn't happen, because every single of those > sections of the perimeter walls would have pierced through the street > level like a hot knife though butter. > > In this didn't happen, because the street level was mainly intact. > > You could easily see that, if you look at any pictures of the aftermath > of 9/11, which show the remains of the twin-towers. > > E.g. you can see, if you look carefully, remains of fire-trucks and > other cars in the rubble, which remained astonishingly undamaged. For > instance some had still unbroken windows. > > This wouldn't be possible, if a just screw-driver would fall from that > hight, let alone sections of the perimeter wall, weighing more then  20 > tons. > ... To give you something to compare the tremendous force of falling debris with, I had figured out, how many Joules of kinetic energy a piece of the perimeter wall had, that falls down from the highest floor at, say, 400m and had a mass of, say, 20 to. The kinetic energy is easy to calculate, if you simply equate it to the energy you need to lift the piece that high. It is in Nm: 9.81*20.000*400 [Nm] =78.480.000 [Nm] That is five times the kinetic energy of an artillery shell. One single piece of that size would punch a significant hole into the ground, large enough for a car to fall down. But each tower consisted of more than half a million tons, hence not only one piece would fall down, but more than 25.000 pieces. TH