Random commentary and senseless acts of blogging.
The first Republican president once said, "While the people retain their virtue and their vigilance, no administration by any extreme of wickedness or folly can seriously injure the government in the short space of four years." If Mr. Lincoln could see what's happened in these last three-and-a-half years, he might hedge a little on that statement.
Prisoners of Azkaban
Wednesday, October 09, 2002
News Item: Physical Laws Still Intact
Avedon Carol posted an item questioning whether fire from the burning planes could have melted the steel columns of the WTC. On one point, the questions were right. The fire wasn't hot enough to actually melt steel, and even if it had been, weakening of the steel from heat would have led to the columns failing to hold the weight above them (probably over 100,000 tons) well before the steel actually liquified. As Carol noted in an update, the towers collapsed mostly because heated steel loses strength. It begins to lose strength at only 425°C, which is about 800°F and actually lower than the temperature of a strong blaze in your fireplace.
The other major factor was that the heat from the fire was very uneven. Heat expands steel, so the uneven fire caused some columns to expand more than others, increasing structural stress. A detailed but not overly difficult account can be found here, (Link courtesy of RRE.)