{"id":101436,"date":"2018-07-22T14:24:44","date_gmt":"2018-07-22T18:24:44","guid":{"rendered":"https:\/\/stateofthenation2012.com\/?p=101436"},"modified":"2018-07-22T14:25:32","modified_gmt":"2018-07-22T18:25:32","slug":"9-11-why-natural-collapse-was-mathematically-impossible","status":"publish","type":"post","link":"https:\/\/stateofthenation2012.com\/?p=101436","title":{"rendered":"9\/11 – Why Natural Collapse Was Mathematically Impossible"},"content":{"rendered":"

\"The

The Twins before the attack on September 11, 2001.<\/p><\/div><\/p>\n

\n

9\/11 – Why Natural Collapse Was Mathematically Impossible<\/h1>\n

What Do You Think<\/h2>\n
\n

Was 9\/11 an Inside Job?<\/h3>\n<\/div>\n<\/div>\n
\n

Why Did They Collapse?<\/h2>\n
\n

It seems hard to prove that the collapse of the Twin Towers was an inside job.<\/p>\n

From the few known facts it appears that the alleged buckling scenario has no mathematical basis, which implies that full collapse was impossible without introducing an unknown force in the core of the building.<\/p>\n

Seismic recordings, from the closest by seismic recording station at Palisades, are often claimed as proof that explosives would be detonated just before the collapse. But this source cannot deliver any proof, because seismic activity prior to the major collapse does not prove the ignition of explosives. It is indirect, and therefore no direct proof.<\/p>\n

The official version tells that the towers collapsed by the heat of the fire after the impact in combination with a damaged main structure. But how likely is it that this fire could cause a perfect full vertical collapse?<\/p>\n

The collapse mechanism of the Twin Towers might look complicated to a layman. But it is not as difficult as it seems. Mathematics is the ultimate key to reveal the hidden truth.<\/p>\n

    \n
  1. This article shows how much energy was released before and during the collapse.<\/li>\n
  2. This article shows which forces were active just before and during the collapse.<\/li>\n
  3. The calculations are accurate enough to draw conclusions from, that lead to an inevitable end conclusion.<\/li>\n
  4. If you have no scientific background, this article will be too difficult to understand<\/em>.\u00a0<\/strong>(You can click the link that jumps to the bottom of this article.)
    \n<\/strong><\/li>\n<\/ol>\n

    \u2192\u00a0<\/a>Conclusion – Why Did the Twin Towers Collapse?<\/a><\/strong><\/p>\n<\/div>\n<\/div>\n

    \n
    \n
    \"\"<\/div>
    Source<\/span><\/span><\/figcaption><\/figure>\n<\/div>\n
    \n

    Facts and Figures Twin Towers<\/h2>\n
    \n\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n
    \n
    Item<\/div>\n<\/th>\n
    		\n
    Figure<\/div>\n<\/th>\n<\/tr>\n<\/thead>\n
    \n
    Height<\/div>\n<\/td>\n
    		\n
    415 meters<\/div>\n<\/td>\n<\/tr>\n
    \n
    Outside perimeter<\/div>\n<\/td>\n
    		\n
    63 x 63 meters<\/div>\n<\/td>\n<\/tr>\n
    \n
    Inside support core<\/div>\n<\/td>\n
    		\n
    24 x 42 meters<\/div>\n<\/td>\n<\/tr>\n
    \n
    Stories<\/div>\n<\/td>\n
    		\n
    110<\/div>\n<\/td>\n<\/tr>\n
    \n
    Floor height (pitch distance)<\/div>\n<\/td>\n
    		\n
    3.77 meters<\/div>\n<\/td>\n<\/tr>\n
    \n
    Basement<\/div>\n<\/td>\n
    		\n
    5 stories – 21 meters<\/div>\n<\/td>\n<\/tr>\n
    \n
    Estimated empty weight (each tower)<\/div>\n<\/td>\n
    		\n
    475,000 metric tons<\/div>\n<\/td>\n<\/tr>\n
    \n
    Estimated operational weight<\/div>\n<\/td>\n
    		\n
    565,000 metric tons<\/div>\n<\/td>\n<\/tr>\n
    \n
    Specific average empty weight<\/div>\n<\/td>\n
    		\n
    1088 kg\/m2<\/div>\n<\/td>\n<\/tr>\n
    \n
    Floor space (each tower)<\/div>\n<\/td>\n
    		\n
    436,590 m2<\/div>\n<\/td>\n<\/tr>\n
    \n
    Max wind load<\/div>\n<\/td>\n
    		\n
    225 km\/h (140 mph)<\/div>\n<\/td>\n<\/tr>\n
    \n
    Construction type<\/div>\n<\/td>\n
    		\n
    Steel \/ egg-crate<\/div>\n<\/td>\n<\/tr>\n
    \n
    Earthquake proof<\/div>\n<\/td>\n
    		\n
    \u2264 Mag 5.0 (P-wave)<\/div>\n<\/td>\n<\/tr>\n
    \n
    Natural (swing) frequency<\/div>\n<\/td>\n
    		\n
    11 sec.<\/div>\n<\/td>\n<\/tr>\n
    \n
    Dampening construction<\/div>\n<\/td>\n
    		\n
    Visco elastic dampers, 100 per floor<\/div>\n<\/td>\n<\/tr>\n
    \n
    Bomb attack<\/div>\n<\/td>\n
    		\n
    February 26, 1993 in basement -2<\/div>\n<\/td>\n<\/tr>\n
    \n
    Airplane attack<\/div>\n<\/td>\n
    		\n
    September 11, 2001 centered on 81st and 95th floor<\/div>\n<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n
    <\/div>\n<\/div>\n<\/div>\n
    \n

    The Twin Towers Compared With Other Tall Skyscrapers<\/h2>\n
    \n
    \"\"<\/div>
    Source<\/span><\/span><\/figcaption><\/figure>\n<\/div>\n
    \n

    Facts and Figures of Other Skyscrapers<\/h2>\n
    \n\n\n\n\n\n\n\n\n\n\n
    \n
    Tower<\/div>\n<\/th>\n
    		\n
    Stories Above Ground<\/div>\n<\/th>\n
    		\n
    Height* (m)<\/div>\n<\/th>\n
    		\n
    Weight** (kg\/m2)<\/div>\n<\/th>\n<\/tr>\n<\/thead>\n
    \n
    Willis Tower (Sears)<\/div>\n<\/td>\n
    		\n
    108<\/div>\n<\/td>\n
    		\n
    442<\/div>\n<\/td>\n
    		\n
    585<\/div>\n<\/td>\n<\/tr>\n
    \n
    Burj Khalifa<\/div>\n<\/td>\n
    		\n
    163<\/div>\n<\/td>\n
    		\n
    584<\/div>\n<\/td>\n
    		\n
    967<\/div>\n<\/td>\n<\/tr>\n
    \n
    Twin Towers<\/div>\n<\/td>\n
    		\n
    110<\/div>\n<\/td>\n
    		\n
    415<\/div>\n<\/td>\n
    		\n
    1088<\/div>\n<\/td>\n<\/tr>\n
    \n
    Petronas Tower<\/div>\n<\/td>\n
    		\n
    88<\/div>\n<\/td>\n
    		\n
    452<\/div>\n<\/td>\n
    		\n
    1376<\/div>\n<\/td>\n<\/tr>\n
    \n
    Taipei<\/div>\n<\/td>\n
    		\n
    101<\/div>\n<\/td>\n
    		\n
    448<\/div>\n<\/td>\n
    		\n
    1709<\/div>\n<\/td>\n<\/tr>\n
    \n
    Empire State Building<\/div>\n<\/td>\n
    		\n
    102<\/div>\n<\/td>\n
    		\n
    381<\/div>\n<\/td>\n
    		\n
    1747<\/div>\n<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n
    Figures are partly derived from Skyscraperpage.com and partly from other sources. *heights are habitable. **Average specific weight, gross floor space.<\/div>\n<\/div>\n<\/div>\n
    \n

    Specific Weight of Skyscrapers Varies<\/h2>\n
    \n

    As you see in the above table the specific weight of skyscrapers varies, from light (Willis Tower) to heavy (Empire State Building). Skyscrapers are heavy at the base and light at the top. The average specific weight of a tower shows how solid the building is, which is also an indicator of its overall strength.<\/p>\n

    Most modern skyscrapers are resistant to S-waved earthquakes, which makes buildings swing like in heavy storms. Towers like the Taipei and Petronas are highly earthquake proof up to respectively 8.3 and 7.6. The Twin Towers were designed to deal with mild earthquakes of magnitude 5.0.<\/p>\n

    Adding mass to high towers is disadvantageous for the swinging characteristics, unless the additional mass outweighs the disadvantages in the form of strength and stiffness. Balancing between these two makes the design process of skyscrapers difficult.<\/p>\n

    The main principles of high towers are simple, the details and actual building extremely difficult.<\/p>\n<\/div>\n<\/div>\n

    \n
    \n
    \"Cross<\/div>
    Cross section Twin Tower, showing the typical damping construction between floors and beams to dampen wind induced vibration and earthquakes.<\/span>\u00a0|\u00a0Source<\/span><\/span><\/figcaption><\/figure>\n<\/div>\n
    \n
    \n
    \"The<\/div>
    The Twin Towers were constructed with a damping factor of 0.2, which results in a ratio of 2.65 between static and dynamic loads.<\/span><\/figcaption><\/figure>\n<\/div>\n
    \n

    Were the Twin Towers Earthquake Proof?<\/h2>\n
    \n

    This is an important question, because it implies the dynamic strength of the tall skyscrapers.<\/p>\n

    The towers were designed to resist a combined S\/P-waved earthquake up to magnitude 5. Buildings tend to be the most vulnerable to S-wave type earthquakes, especially when they are close to their natural frequency (Twin Towers 11 seconds).<\/p>\n

    There were approximately 10,000\u00a0viscoelastic dampers<\/em>\u00a0installed in each tower to reduce wind-induced vibrations and S-waved vibrations from earthquakes. The earthquake of magnitude 4.0 in October 19, 1985 went by unnoticed. The towers had, as expected, no problem handling this, as most other buildings by the way.<\/p>\n

    The viscoelastic dampers as shown in the flanking picture absorb most energy released by an earthquake on a tower, which were evenly distributed from the 10th<\/sup>up to the 110th<\/sup>\u00a0floor. What these dampers do is (partly) cancelling out destructive energy that might harm the construction.<\/p>\n

    A typical ground acceleration pattern where the tower were designed on was approximately 15% g – 1.5 m\/s2<\/sup>.<\/p>\n

    To find the correct dynamic load for welded steel constructions the maximum static load has to be divided by 2.65 (damping factor \u03b6=0.2). This is the so called Dynamic Amplification Factor (DAF). I left out the extensive calculations. The results:<\/p>\n

      \n
    • P-waves: +15% x 2.65 = 40%<\/li>\n
    • S-waves: +113% x 2.65 = 300%<\/li>\n
    • Combined P\/S waves: (1.4 x 3) x 100% = 420%<\/li>\n<\/ul>\n

      Due to the earthquake resistance the construction could carry in static circumstances approximately 420% of the weight of the towers at ground zero level.<\/p>\n

      The Twin Towers had a specific design. The outer cage which gave the towers a specific look, acted as the major resistor against swinging. It made the towers extremely stiff. This high stiffness had consequences for the structure in the core, which had to take higher loads. The core structure had to be approximately 21% stronger.<\/p>\n

      This resulted in a building that was able to withstand 508% of its own empty weight in static situations.<\/p>\n<\/div>\n<\/div>\n

      \n
      \n
      \"\"<\/div>
      Source<\/span><\/span><\/figcaption><\/figure>\n<\/div>\n
      \n

      Storm Resistance of the Twin Towers<\/h2>\n
      \n

      This is an important factor in the case of 9\/11, because it was a day with not much wind, which means that the full overcapacity in strength was available.<\/p>\n

      The towers were designed to handle wind speeds up to 225 km\/h (140 mph). This is a dynamic load similar as with the horizontal motions (S-waves) during earthquakes. The maximum handleable wind load results in a force at the base that equals approximately 18% of its own weight.<\/p>\n

      This load is dynamic as well, which means it has to be factored with 2.65. The result is an extra required strength of 48%. Since earthquakes and wind load were possible to occur at the same moment, this was taken into account.<\/p>\n<\/div>\n<\/div>\n

      \n

      Total Static Strength<\/h2>\n
      \n

      A usual safety factor in large constructions is 1.3.<\/p>\n

      The result is that the main structure of the towers at ground level were all together dimensioned at least:<\/p>\n

        \n
      • 978%<\/strong>\u00a0(9.78 times) stronger than its weight in a\u00a0static situation<\/em>.<\/li>\n<\/ul>\n

        So due to all possible dynamical loads were the Twin Towers\u00a0at base level<\/strong>\u00a0capable to carry about 10 times there own weight in a\u00a0static<\/em>\u00a0situation.<\/p>\n<\/div>\n<\/div>\n

        \n

        The Higher – The Less Strong<\/h2>\n
        \n

        The main structure of the towers was at top level less strong constructed than at ground level. Material = Money. As a rule of thumb this formula is applicable for the Twin Towers:<\/p>\n

          \n
        • Vertical static strength Ps[n]max<\/sub>\u00a0\u2248 (9.78 – (9.78*(floor\/110)) + 0.1) x 4.66 GN<\/li>\n
        • Vertical Dynamical Strength Pd[n]max<\/sub>\u00a0= Ps[n]max<\/sub>\u00a0\/ 2.65<\/li>\n
        • Static strength 81st floor Ps[81]max<\/sub>\u00a0\u2248 12.5 GN (2.67 times own empty weight)<\/li>\n
        • Static strength 95th floor Ps[95]max<\/sub>\u2248 6.7 GN (1.43 times own empty weight)<\/li>\n
        • Dynamic strength 81st floor Pd[81]max<\/sub>: 4.7 GN (1.01 times own empty weight)<\/li>\n
        • Dynamic strength 95th floor Pd[95]max<\/sub>: 2.5 GN (0.54 times own empty weight)<\/li>\n<\/ul>\n

          These figures are important in the collapse mechanism that is shown further on. The weight of the interior plays a role as well.<\/p>\n

          The formula will come at hand, later, when the dynamic collapse behaviour of the towers are regarded.<\/p>\n<\/div>\n<\/div>\n

          \n

          How Impact Proof Were the Twin Towers?<\/h2>\n
          \n

          Empirical determination is the best way to find out the impact resistance of a building.<\/p>\n

          On February 26, 1993 a bomb exploded in the basement of 550 kg (TNT equivalent), which is equivalent to 2,3GJ. The explosion damaged 4 floors, together 16,000 m2<\/sup>(50,000 ft2<\/sup>). There was damage on floors just above and below the explosions. But there was no damage to the main structure that carried the full weight of the tower.<\/p>\n

          Based upon this event it is possible to determine the resistance of the building against explosions (impacts), which was\u00a0at least<\/em>\u00a00.144 MJ\/m2<\/sup>\u00a0in 15 ms[1]<\/sup>\u00a0(the average horizontal blast time to nearby walls) at basement level. It indicates that the main structure could withstand 34.5 GJ\/m2<\/sup>\/hour. This is\u00a0very<\/em>\u00a0high.<\/p>\n

          The basement was stronger than the rest of the tower. For the main support structure of high rise buildings counts the rule – the higher, the weaker.<\/p>\n

          The towers were constructed to handle an impact of a Boeing 707-320B flying at a speed of 907 km\/h (607 mph), weighing 152,400 kg (336,000 pounds). The energetic equivalent of this is 4.8 GJ (1,160 kg TNT).<\/p>\n

          The Boeing 767 that hit tower 1 weighed about 180 metric tons and flew around 503 mph, which equals 225 m\/s. The kinetic energy that this plane released onto a small part of the construction of the tower was 4.6 GJ.<\/p>\n

          The actual impact of the Boeing 767 on 9\/11 was\u00a096% of the design specifications<\/em><\/strong>, which indicates that the main structure at this height could be have been damaged. The exact amount of damage is not easy to determine, but by screening eyewitness statements, it is possible to determine the approximate amount of damage.<\/p>\n

          In both cases it appeared that the planes allegedly affected the main construction, covering 24,000 m2<\/sup>. Since the local main construction did not collapse under this impact energy means that the main structure was able to handle on floors 81 and 95at least<\/em>\u00a00.47 MJ\/m2<\/sup>\u00a0in 245 ms[2]<\/sup>\u00a0(this was the calculated duration of impact). This equals 6.9 GJ\/m2<\/sup>\/hour. This is also\u00a0very<\/em>\u00a0high.<\/p>\n

          With these two impacts it is possible to determine the course (a graphic analysis) of the\u00a0minimum<\/em>\u00a0impact resistability of the main structure: 34.5 GJ\/m2<\/sup>\/hour at basement level and 6.9 GJ\/m2<\/sup>\/hour at the 95th<\/sup>\u00a0floor.<\/p>\n<\/div>\n<\/div>\n

          \n

          How Fireproof Were the Twin Towers?<\/h2>\n
          \n

          The planes carried around 38,000 liters of kerosene (10,000 gallons), which had an energetic value of 1.6\u00d71012<\/sup>\u00a0J (1,6 TJ). During the impact the liquid explosion spread over 6 floors which equals average 67.2 MJ\/m2<\/sup>.<\/p>\n

          The towers were designed to handle a theoretical fire load of 220 MJ\/m2<\/sup>\/hour. The towers were constructed to handle this amount of energy, spread during 4 hours (cumulative 880 MJ\/m2<\/sup>). When a fire becomes hot enough almost anything starts to burn, from paint to even aluminium. An average office contains 600 MJ\/m2<\/sup>combustible materials.<\/p>\n

          The kerosene must have burned in less than 2 minutes (estimation<\/em>), meaning that the permissible fire load of the towers could have been exceeded during the time the kerosene caught fire over 6 floors. With a short fire load of\u00a0maximum<\/em>\u00a02,000 MJ\/m2<\/sup>, the overload would be approximately 920%,\u00a0assuming<\/em>\u00a0that all the kerosene burned inside the towers. But since a part of the kerosene exploded outside the towers means that it was less. How much less?<\/p>\n

          The volume of the fire ball around tower 1 during the hit was approximately 2,3×106<\/sup>m3<\/sup>. The fire ball could freely expand since the windows were already blown out. The total volume of the affected 6 floors was 9×104<\/sup>\u00a0m3<\/sup>. This means that around 5% of the kerosene burned inside the tower. Kerosene is so inflammable that it doesn’t burn up slowly. The perimeter of the explosion shows that there was no ‘place’ inside the building to burn this amount of kerosene.<\/p>\n

          Because only 5% of the kerosene burned inside the towers, means that the fire load was not more than 240 MJ\/m2<\/sup>\u00a0during less than 2 minutes. The towers were able to handle this amount of energy easily. They were designed on this fire load, not just for 2 minutes but during 4 hours.<\/p>\n

          The heat of the fire after the impact was no problem. A kerosene fire of a few minutes doesn’t develop more heat than 600 \u00b0C – 700 \u00b0C (1110 \u00b0F – 1290 \u00b0F). The steel construction was coated with a heat resistant material, designed and applied to handle this heat for at least 4 hours. Whether the main structure at the height of impact was unaffected by this first heat burst is unsure, since the thermal isolation might have been damaged by the impact.<\/p>\n

          The kerosene was a spark that ignited a larger fire. Additionally, the blast of the liquid explosion blew away part of the combustible materials. That means it didn’t took part in the fire.<\/p>\n

          The total energetic value of the kerosene was a fraction of the energy necessary to bring the main structure in the danger zone. The kerosene plays hardly a role in the energetic balance, besides being the igniter of a much more dangerous fire – a burning office of 600 to 700 \u00b0C.<\/p>\n

          The towers were designed to handle this heat and fire load. Although parts of the protective coating might have been damaged due to the impact, which made the main structure vulnerable for the heat that followed.<\/p>\n<\/div>\n<\/div>\n

          \n

          Could the Aluminium Airplane Burn?<\/h2>\n
          \n

          Maybe. Metal combustion is possible. Aluminium has a very high energy density of 31 MJ\/kg, which is much more than TNT. Some explosives are based on the highly corrosive properties of aluminium, as well as some types of solid rocket fuel. Aluminium alloys show complicated mechanical, thermal and chemical behaviour.<\/p>\n

          Scientists observed several ignition processes of aluminium:<\/p>\n

            \n
          1. aluminium can start to ignite at temperatures around 1,700 \u00b0C (3100 \u00b0F), when the protective oxide shell loses integrity.<\/li>\n
          2. aluminium can start to ignite at temperatures around 1,150 \u00b0C (2100 \u00b0F), when the protective oxide shell shows mechanical cracks.<\/li>\n
          3. aluminium can start to ignite at 650 \u00b0C (1200 \u00b0F) by shock waves which fractures the protective oxide shell.<\/li>\n<\/ol>\n

            The latter situation (3) could be the case in the 9\/11 attacks, which would add a significant amount of energy to the fire.<\/p>\n

            A Boeing 767 contains around 70,000 kg aluminium (in several alloys). If this amount of aluminium burned in a short time it unleashed an amazing 2.2 TJ, spread over 6 floors and cause an additional average energy of 100 MJ\/m2<\/sup>. At some points of the building an alleged aluminium fire could have been very concentrated and therefore fearsome. But the building was able to handle this heat\u00a0and<\/em>\u00a0energy at that time. When aluminium starts to burn it does so very quickly. And when this heat source would have been responsible, it would have caused a collapse almost immediately after the impact.<\/p>\n

            So, there are no indications that burning aluminium would have been a major problem.<\/p>\n

            Even in the case the full aluminium body caught fire, the main structure of the building was still far from the danger zone of collapse, at least with an intact thermal isolation.<\/p>\n<\/div>\n<\/div>\n

            \n
            \n
            \n
            <\/div>\n
            \n

            I heard three explosions, and then we heard like groaning and grinding, and tower two started to come down.<\/p>\n

            \u2014 Eyewitness Reports (911review.com)<\/span><\/p>\n<\/div>\n<\/div>\n<\/div>\n<\/div>\n

            \n

            Facts & Figures September 11, 2001<\/h2>\n
            \n\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n
            \n
            Item<\/div>\n<\/th>\n
            		\n
            Value<\/div>\n<\/th>\n<\/tr>\n<\/thead>\n
            \n
            Mean wind speed \/ direction (origin)<\/div>\n<\/td>\n
            		\n
            11 km\/h (7 mph) \/ NNW<\/div>\n<\/td>\n<\/tr>\n
            \n
            Temperature<\/div>\n<\/td>\n
            		\n
            20 \u00b0C (68.1 \u00b0F)<\/div>\n<\/td>\n<\/tr>\n
            \n
            Visibility<\/div>\n<\/td>\n
            		\n
            15 km (9.5 mi)<\/div>\n<\/td>\n<\/tr>\n
            \n
            Time impact tower 1 (North)<\/div>\n<\/td>\n
            		\n
            8:46 AM<\/div>\n<\/td>\n<\/tr>\n
            \n
            Time impact tower 2 (South)<\/div>\n<\/td>\n
            		\n
            9:03 AM<\/div>\n<\/td>\n<\/tr>\n
            \n
            Height impact tower 1<\/div>\n<\/td>\n
            		\n
            95th floor<\/div>\n<\/td>\n<\/tr>\n
            \n
            Height impact tower 2<\/div>\n<\/td>\n
            		\n
            81st floor<\/div>\n<\/td>\n<\/tr>\n
            \n
            Time collapse tower 1<\/div>\n<\/td>\n
            		\n
            10:28 AM<\/div>\n<\/td>\n<\/tr>\n
            \n
            Time collapse tower 2<\/div>\n<\/td>\n
            		\n
            9:59 AM<\/div>\n<\/td>\n<\/tr>\n
            \n
            Impact-collapse time tower 1<\/div>\n<\/td>\n
            		\n
            102 minutes<\/div>\n<\/td>\n<\/tr>\n
            \n
            Impact-collapse time tower 2<\/div>\n<\/td>\n
            		\n
            56 minutes<\/div>\n<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n
            <\/div>\n<\/div>\n<\/div>\n
            \n
            \n
            \"\"<\/div>
            Source<\/span><\/span><\/figcaption><\/figure>\n<\/div>\n
            \n

            Required Collapse Energy<\/h2>\n
            \n

            The towers were designed to handle:<\/p>\n

              \n
            • an air plane impact of similar size,<\/li>\n
            • a fire load of 3.5 GJ\/m2<\/sup>.<\/li>\n<\/ul>\n

              The structural analysis done by Worthington, Skilling, Helle & Jackson is one of the most thorough calculations ever made for any building structure.<\/p>\n

              The amount of energy (up to 700 \u00b0C) each level could handle before collapsing was\u00a014 TJ<\/strong><\/em>.<\/p>\n

              Required collapse energy:<\/p>\n

                \n
              • The impacts were centred on floor 81 and floor 95, spread over 6 floors.<\/li>\n
              • Tower 1 collapsed after 102 minutes over 6 floors – the necessary energy the fire would have to produce for this would be: 84 TJ (6 x 14), which equals 23.3 GWh (!)<\/li>\n
              • Tower 2 collapsed after 56 minutes over 6 floors – this also requires 84 TJ or 23.3 GWh.<\/li>\n
              • All possible energy together was: plane impact + kerosene + aluminium body = 4.6 GJ + 1,600 GJ x 5% + 2,200 GJ \u2248 2.3 TJ. This energy was applied from outside to inside. The thermal isolation was designed for much more.<\/li>\n
              • The only heat source that possibly could bring the construction in the danger zone was ignition of the aluminium body of the airplane. Especially in combination with a damaged thermal insulation.<\/li>\n
              • Nevertheless was the released energy on floor 95 of Tower 1 just 6% of the energy necessary to bring the\u00a0main structure<\/em>\u00a0in the danger zone (2.3 \/ 14 x 35%) see table below.<\/li>\n
              • This energy was not equally spread over 6 floors. The impact on tower 1 was centred on floor 95. The spread was likely to be as in the table below. Floor 95 took 35% of the load.<\/li>\n
              • In both cases is over 90% of the energy missing to bring 6 floors altogether down.<\/li>\n
              • Even if the thermal insulation was damaged, doesn’t mean that\u00a0all<\/em>\u00a0the thermal insulation was damaged.<\/li>\n<\/ul>\n

                Nevertheless looking at the facts – both towers collapsed, allegedly caused by the fires.<\/p>\n

                Around six floors were affected by impact and fire. The collapse would logically start at the floor that was the most affected by the fires – floor 81 and 95 of respectively tower 2 and tower 1. The main structure just above and below these floors was weakened but had more resistance, which was approximately in proportion with the rate of impact.<\/p>\n

                  \n
                • Tower 2 collapsed towards the place of impact. This seems logical to me, which made me decide not to delve deeper into tower 2.<\/li>\n<\/ul>\n
                    \n
                  • Tower 1 collapsed in a strange way. The tower was impacted from the North side, while it initially started to collapse on the South side (check out the direction of the smoke when studying collapse videos, wind origin was NNW).<\/li>\n<\/ul>\n

                    The collapse mechanism of tower 1 is fully illogical. I looked deeper into it and discovered interesting things and strange things, until I bumped onto mathematical impossibilities.<\/p>\n<\/div>\n<\/div>\n

                    \n

                    Impact Silhouette Tower 1<\/h2>\n
                    \n
                    \"\"<\/div>
                    Source<\/span><\/span><\/figcaption><\/figure>\n<\/div>\n
                    \n

                    Estimated Impact Spread Tower 1<\/h2>\n
                    \n\n\n\n\n\n\n\n\n\n\n
                    \n
                    Floor Level<\/div>\n<\/th>\n
                    		\n
                    Amount of Absorbed Energy<\/div>\n<\/th>\n<\/tr>\n<\/thead>\n
                    \n
                    93<\/div>\n<\/td>\n
                    		\n
                    5%<\/div>\n<\/td>\n<\/tr>\n
                    \n
                    94<\/div>\n<\/td>\n
                    		\n
                    15%<\/div>\n<\/td>\n<\/tr>\n
                    \n
                    95<\/div>\n<\/td>\n
                    		\n
                    35%<\/div>\n<\/td>\n<\/tr>\n
                    \n
                    96<\/div>\n<\/td>\n
                    		\n
                    35%<\/div>\n<\/td>\n<\/tr>\n
                    \n
                    97<\/div>\n<\/td>\n
                    		\n
                    7%<\/div>\n<\/td>\n<\/tr>\n
                    \n
                    98<\/div>\n<\/td>\n
                    		\n
                    3%<\/div>\n<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n
                    <\/div>\n<\/div>\n<\/div>\n
                    \n

                    The Official Version<\/h2>\n
                    \n
                    \"\"<\/div>
                    Source<\/span><\/span><\/figcaption><\/figure>\n<\/div>\n
                    \n

                    Tower 1 – The Collapsing North Tower<\/h2>\n
                    \n

                    The collapse of the North Tower (Tower 1) is strange. In the video below you must keep in mind that the airplane came from the right. The wind was coming from NNW. Now pay careful attention how it collapses.<\/p>\n

                      \n
                    1. You see the tower first collapsing on the left side. This is the opposite side of impact. The construction was the most intact on precisely this side.<\/li>\n
                    2. At the moment the collapse starts you see flames coming from the right front side. This was the left side of impact. This indicates that there was only a fire on this side. It didn’t seem to burn anymore on the left side – the side of initial collapse – the opposite side of the impact. It nevertheless collapsed here first. It is strange.<\/li>\n<\/ol>\n<\/div>\n<\/div>\n
                      \n
                      \n