[PhilWeb] Re: Götterdämmerung in der Philweb-Lounge

Hi IM, der NIST Report ist doch vielfach für seine Unvollständigkeit kritisiert worden, bspw. in den Arbeiten "A theory for the collapse of the World Trade Center": https://www.sciencedirect.com/science/article/abs/pii/S1350630713002604?via… <https://www.sciencedirect.com/science/article/abs/pii/S1350630713002604?via=ihub> Und "What Did and Did not Cause Collapse of WTC Twin Towers in New York:“ http://www.civil.northwestern.edu/people/bazant/PDFs/Papers/00%20WTC%20Coll… <http://www.civil.northwestern.edu/people/bazant/PDFs/Papers/00%20WTC%20Collapse%20-%20What%20Did%20&%20Did%20Not%20Cause%20It.pdf> Auch einen Film kannst Du Dir dazu anschauen: https://nrodlzdf-a.akamaihd.net/de/zdf/22/03/220310_11_september_inf/1/2203… <https://nrodlzdf-a.akamaihd.net/de/zdf/22/03/220310_11_september_inf/1/220310_11_september_inf_3360k_p36v15.mp4> Es geht nicht um die Erlaubnis von Antworten, sondern darum, wie sie begründet werden. Warum müssen Explosionen denn durch Sprengungen bewirkt worden sein? Schwingt da vielleicht ein Vorurteil mit? Bei Frank Greening u.a. heißt es im Abstract: "Previous analysis of progressive collapse showed that gravity alone suffices to explain the overall collapse of the World Trade Center (WTC) towers. However, it remains to be checked whether the recent allegations of controlled demolition have any scientific merit. The present analysis proves that they do not. The video record available for the first few seconds of collapse is shown to agree with the motion history calculated from the differential equation of progressive collapse but, despite uncertain values of some parameters, it is totally out of range of the free fall hypothesis, on which these allegations rest. It is shown that the observed size range (0.01 mm—0.1 mm) of the dust particles of pulverized concrete is consistent with the theory of comminution caused by impact, and that less than 10% of the total gravitational energy, converted to kinetic energy, sufficed to produce this dust (whereas more than 150 tons of TNT per tower would have to be installed, into many small holes drilled into concrete, to produce the same pulverization). The air ejected from the building by gravitational collapse must have attained, near the ground, the speed of almost 500 mph (or 223 m/s, or 803 km/h) on the average, and fluctuations must have reached the speed of sound. This explains the loud booms and wide spreading of pulverized concrete and other fragments, and shows that the lower margin of the dust cloud could not have coincided with the crushing front. The esisting upward forces due to pulverization and to ejection of air, dust and solid fragments, neglected in previous studies, are found to be indeed negligible during the first few seconds of collapse but not insignificant near the end of crush-down. The calculated crush-down duration is found to match a logical interpretation of seismic record, while the free fall duration grossly disagrees with this record.“ Und Christian J. Simensen fasst zusammen: "Two airplanes of type Boeing 767 flew into the Twin Towers in the morning of September 11th 2001. The crashes caused fuel to ignite, and the airplanes to be cut to pieces and be buried under building fragments. They were subsequently heated to a high temperature. 30 tonnes of aluminium alloys in the airplanes were melted at 660 °C while the surrounding building was only heated to a much lower temperature due to insulation effects. When the temperature reached 750–800 °C, the huge amount of aluminium melt managed to stream down to the lower floors. There it came in contact with water from the automatic sprinkler devices and possibly other sources. This encounter resulted in a series of fierce explosions due to the generation of hydrogen gas and local heating to high temperatures well above 1200 °C. A complete floor of the buildings was blown apart, and the upper part fell onto the bottom part leading to a complete collapse.“ IT