World Trade Center collapse

Not a forensic case as discussed here — rather, the paper itself ("Why the World Trade Center Collapsed," Eagar & Musso) as an example of writing-for-non-specialists. Tom contrasts the three hours he spent on it (and its outsized citation impact) with the hundreds of obscure peer-reviewed papers he wrote that nobody read. The paper's substantive content (the steel-melting misconception) is mentioned but not developed in this lecture. ## Figures referenced (not cases)

There's another paper I'm going to give you, "Why the World Trade Center Collapsed." A lot of you have seen this paper before. I give these out to a lot of students. I've written in my career a couple of hundred peer-reviewed publications. I remember the first day I made as an assistant professor, I met with Walter Owen, the department head. He said, no matter what anyone tells you, it really is publish or perish. That was the only advice he gave me in the next six years while I was a young assistant professor. But you have to publish.

Tom mentions his WTC paper as a course handout, notes it was long the top-Googled WTC-collapse article, and flags an upcoming BBC documentary interview. Asserts "it was the airplanes" against conspiracy theorists.

There's a copy of my World Trade Center paper. We'll probably talk about that at some point. For a long time, that was the most referenced article on the World Trade Center collapse. I was number one on Google, I think I'm number two now. All the conspiracy theorists hate me because I explained it. In fact the BBC is doing a documentary, and next Thursday — not this Thursday but next Thursday — I'll be down in the Washington area and they want me to meet with them, because they're doing a documentary on the World Trade Center. By the way, it was the airplanes. It wasn't a government conspiracy. I'll tell you some of my favorite stories on those things later. It's amazing what people can believe.

Used as an example of writing simply and quantitatively; also as anecdote about online conspiracy attacks on Tom.

One important teaching secret is: why would someone spend an entire lecture doing a derivation on the board? You've all been in an engineering class or a science class where they solve some fourth-order partial differential equation, and they screw it up all the time. Why would they do that? The simple answer is they didn't have time to prepare a lecture. There are some articles to read. I suggest you read "Why Did the World Trade Center Collapse?" — not because I wrote it, but I did. And for nine years I was number one. If you looked up "WTC collapse" on the internet, you would find this paper was number one. The reason was, I wrote it simply. So this is, I think, an example of how I would like you to write your papers. It's also quantitative. I put real numbers in there. I've also become the brunt of all the conspiracy theorists in the world about the World Trade Center. They've had websites against me and they've written to the president of MIT saying I should lose my tenure because I'm a shill for the government. I'm just trying to make America great again. Geez.

To give you an example of some of the things I just said: I was asked in late September of 2001, right after 9/11, by the editor of a metallurgical journal if I would write an article. Actually he didn't ask me, he asked Professor Clark, and Professor Clark said, "Oh, you ought to get Professor Eagar to do it." So he asked me, and I was so sick and tired of reading newspaper accounts about how the steel melted in the fire of the airplanes. Anyone who's ever been to a fire scene knows that steel doesn't melt in a fire. If steel melted in a fire, why did we need Sir Henry Bessemer in 1856 to tell us how to melt steel? The typical temperature of a fire is about 1,000° centigrade. Steel melts at 1500. I've seen a steel derrick where they had a blowout at 10,000 PSI of natural gas from a gas well in Oklahoma, and it catches on fire for three days, and the flames are 300 feet in the air, and the whole derrick is engulfed in flames for three days, and the steel didn't even transform to austenite above 900 centigrade. And I'm reading these great scholars, the newspaper reporters, talking about — or they interview great experts — "Well, the steel melted in the fire."

Towers were built to 1.67 safety factor and survived the airplane impact as designed. Failure was from 20,000 gallons of jet fuel fire per floor, which exceeded combustible-load fire design basis. Code response was not to increase steel (Tom argues this would have priced people out of buildings) but to improve egress standards and public announcement protocols. No-fly zone post-attack prevented rooftop helicopter rescue of victims above the fire floors.

Not necessarily the safety factor, but the design rules. For example, the Twin Towers were built to a safety factor 1.67. They were designed to survive an airplane impact, and they did. It was the fire afterwards. They were designed to survive fires, small fires like the combustibles in the room. They weren't designed to survive 20,000 gallons of fuel on one floor all at once. You can see some pictures where the whole floor is glowing red, and all the beams everywhere were getting weak, and eventually they just started pancaking and going down. What they tightened up after the World Trade Center was not, well, we've got to start putting more steel in buildings — you can barely afford to build the buildings anyway. If you double the steel, you've got to make not just the steel but the windows, everything else goes up in price.

Tom's 2001 paper, written in three hours for a non-technical audience, is given to students as both a content reference (steel does not melt in ordinary fires) and a methodology example (writing for the lay reader). The paper has generated ongoing correspondence including continuing emails from conspiracy theorists fifteen years later.

I handed out a paper on the World Trade Center. I wrote this paper because some editor of a journal asked Professor Joel Clark about three weeks after the World Trade Center collapse if he would write an article. He said, well, why don't you ask Tom Eagar. I was so sick of reading newspaper articles about how the steel melted in the fire that I said yes. Any idiot who's ever been to a fire scene knows that steel doesn't melt in a regular old fire. But all the editors and reporters didn't know that. So I decided to write a paper.

Methodological aside on writing about a subject when you have no specialized expertise — go back to freshman physics and chemistry. Tom's paper as an example.

I handed out the World Trade Center paper. I spent three hours putting that paper together. I've had more comments on that than all the other several hundred publications combined. I wrote it because I was tired of hearing all this stuff that I knew was false, but I really didn't know anything about the World Trade Center. But I did know some basic physics and chemistry. What can you say about something when you know nothing at all about a subject? You can go back to your freshman physics and chemistry and start saying, what do I know? I knew about flames and thermodynamics and flame temperatures and various things, and that's what I wrote about. It still stands today. I just got a nice letter from some lady this weekend who was reading it because of 9/11. She thanked me for writing it. I wrote it because I'd done less work on that than anything else I'd ever worked on. But I wrote it in a way that people could understand, and on a subject people cared about, as opposed to my research — no one cares about my research. It's too specific, too narrow. People want to know about bigger, broader things, which is what I lecture about.

Tom's December 2001 JOM article (with co-author Christopher Musso) explaining the structural failure mode. Used pedagogically as the prime example of "write it so high schoolers can understand," and as the entry point for his lifelong argument with the 9/11 truther community. Three towers, each with 20,000 gallons of fuel; steel lost ~70% strength; not melted.

We talked about communications. When I started as a young faculty member, my department head Walter Owen brought me in and said, no matter what anyone else does, publish or perish. So I published papers and graduate students and research articles. But what happened is, after the World Trade Center collapse, about three weeks afterwards, Joel Clark got a request from the editor of a metallurgical journal saying, will you write an article about the World Trade Center collapse? Joel said, well, ask Tom Eagar. So they asked, would you write an article for the Journal of Metals, JOM? This was published in December 2001. It took me about three or four weeks to gather some information and write this article. Christopher Musso, my graduate student, helped me with some research, so he's co-author. The reason I was willing to write it: I was sick of hearing all the misinformation and incorrect information that was in the press.

Tom's National Geographic special appearance. Used to demonstrate (a) what shaped charges actually do and (b) that the thermite-reaction conspiracy theory was disproven by full-scale testing at the New Mexico Tech explosives research center.

[Tom produces a shaped-charge copper piece.] This is a shaped charge piece of copper. It's a saucer-shaped piece, and it's got little places where you would put a little bit of explosive in each one. When you set it off, the saucer inverts — you'll have a downward force on the outside rim, the thing inverts, and all the copper is squeezed into the center underneath. As it does that, you'll have adiabatic heating and the copper will melt, and you'll shoot out a jet of liquid copper. That jet will penetrate a piece of steel to about whatever the length of the piece of copper is, and it will do it in microseconds. So this is one shaped charge design.

Tom's three-hour-written 2001 article for a metallurgical journal — produced from chemistry, physics, and fire-investigation first principles without specialized prior knowledge. Used to illustrate (a) the Tufte "fuzzy writing = fuzzy thinking" principle Tom was applying, (b) the unexpected reach of clear technical writing pitched at high-school level, (c) the conspiracy-theory backlash he received. Tom assigns the article as a reading.

There is an article on why the World Trade Center collapsed. I give you this because it's an article I wrote. I was asked, three weeks after the World Trade Center collapsed, by the editor of a metallurgical journal if I would write something. I was so sick of hearing all the falsehoods — fake news, I guess is the term today — that were being put out in the press. I said okay, I'll write an article. I spent three hours, with the help of a student, writing this article. I really didn't know much of anything about the World Trade Center, but I knew some chemistry and I knew some physics and I had done some fire investigations, so I just talked about what I knew and what the scientific principles were. And I also knew — remember, fuzzy writing is the result of fuzzy thinking — I was going to pitch it to a high school science student, that was the level.