Despite the impulse to rebuild, the size of skyscrapers such as the World Trade Center Towers makes them attractive targets to terrorists, says a Swarthmore College professor. According to physics professor Frank Moscatelli, of the three sources of energy delivered to New York City Tuesday morning -- exploded jet fuel, kinetic energy due to the motion of two aircraft, and gravitational potential energy due to the falling building material -- the last is the most devestating.
"My calculations show that the largest component by far was the latter," says Moscatelli, a native New Yorker. "This is due to the large mass and height of the towers. Their splendor was their undoing."
According to Moscatelli, the numbers, in metric Joules, are:
1. 6.9x10^10 (both planes)
2. 1.9x10^9 (both planes)
3. 6.8x10^11 (both towers plus sundry other collapses)
"This is equivalent to the detonation of 0.2 Kilo tons of TNT," Moscatelli says. "As comparison, the Hiroshima bomb was 10 kilo tons TNT equivalent." Moscatelli estimates these numbers to be accurate to within about 25 percent.
"Being from New York, I understand the desire to rebuild those towers," Moscatelli says. "But we might consider for a moment the wisdom of reconstructing buildings that stick out as such clear targets and hold such destructive potential as well."
Cite This Page: