Wikipedia:Reference desk/Archives/Miscellaneous/2022 September 7

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September 7

Was there really no explosion when the first plane hit on 9/11? This goes for the other three planes as well.

In a previous talk page message, a user claimed that when Flight 11 crashed into the North Tower, there was no explosion, "merely a fireball emerging seconds later from the north side where the plane entered." Is this true? I was always under the impression those blasts you see when the planes hit were explosions. At least, the one that hit the South Tower looked pretty explosive to me. I'm not saying they're wrong or anything, I'd just kinda surprised if there really wasn't an explosion there. Hmm1994 (talk) 02:58, 7 September 2022 (UTC)

According to the explosion article: An explosion is a rapid expansion in volume associated with an extremely vigorous outward release of energy, usually with the generation of high temperatures and release of high-pressure gases. Millions of us saw the 2nd tower hit live on TV; and, by that definition, it sure looked like an explosion. There is no rational reason to believe the impact on the 1st tower was substantially different. 136.56.52.157 (talk) 06:38, 7 September 2022 (UTC)

It may "look like" an explosion, but this does not imply it is an explosion. While jet fuel is highly flammable, igniting it does not cause it to explode. For a flammable substance to become explosive, it needs to be mixed in advance, in the right concentration, with (a source of) oxygen. For a detailed reconstruction, see Section 2 of the NIST report on the collapse of the WTC towers.  --Lambiam 09:26, 7 September 2022 (UTC)

One reason why burning gasoline looks like an explosion is that movies and television have taught us that. Most real explosions look rather uninteresting. So special effects makers use a device that disperses a cloud of gasoline droplets in the air and sets the cloud on fire. That is why we think explosions look like gasoline fireballs. 85.76.9.156 (talk) 11:02, 7 September 2022 (UTC)

"Explosion" has a somewhat loose definition. A lot of jet fuel burned within seconds, causing quite a rapid expansion of the air with a large release of energy. I think we can all agree that there was no detonation, which has a more precise meaning. PiusImpavidus (talk) 11:06, 7 September 2022 (UTC)

So, here's the question: If there was a fireball, what was propelling that fireball outward? Sounds like an explosion to me. --Jayron32 14:28, 7 September 2022 (UTC)

Quote from the NIST report: "A surge of combusting fuel rapidly filled the floors, mixing with dust from the pulverized walls and floor slabs. The pressure created by the heated gases forced the ignited mist out the entrance gash and blown-out windows on the east and south sides of the tower. The resulting fireballs could be seen for miles, precipitating many 9-1-1 calls."  --Lambiam 14:56, 7 September 2022 (UTC)

The momentum of the mass of the liquid. If you throw a bucket of fuel gasoline over a candle, the gasoline won't magically stop and get suspended in the air after being lit, it will continue on its trajectory.

If you want to see burning liquids in motion, search flambe on YouTube. Burning + momentum is not an explosion. (And I am seriously trying to be helpful here, not equating food preparation with a horrific tragedy. Must say this because of all the cancellers out there.) 85.76.9.156 (talk) 15:00, 7 September 2022 (UTC)

That's the entire point. The OP stated "there was no explosion, merely a fireball emerging seconds later", they're words not mine. If there is a fireball, for any reasonable definition of the (admittedly very poorly delineated) word "explosion", they are the same thing. In other words, the OPs note of a "fireball, but not an explosion" is nonsensical. --Jayron32 15:17, 7 September 2022 (UTC)

I wasn't suggesting there was a "fireball, not an explosion"; I was merely expressing confusion at someone else (Lambiam) asserting that was the case and obviously had to quote their claim for the purpose of my question. Not trying to insult or denigrate anybody here, I just don't know much about the science of it all. The NIST report-quoted explanation Lambiam provided does sound plausible to a layman like myself, but at the same time I do agree with Jayron32's assessment that the fireball you see emerging from the towers looks like it would require an explosion to actually be propelled outwards in the first place. Hmm1994 (talk) 15:37, 7 September 2022 (UTC)

One can watch fire eaters breathe out fireballs^[1]; these fireballs are propelled outwards without requiring an explosion. All that is needed is pressure forcing the spray out through an existing opening.  --Lambiam 21:56, 7 September 2022 (UTC)

The meaning of "fireball" is even less defined than that of "explosion". An explosion is a rapid expansion of a fluid medium, releasing a high amount of energy in a brief time. There is no precise definition drawing a line between rapid and not-rapid expansions, or between high and not-high amounts of energy, but usually the term "explosion" is reserved for expansions that are destructive to forms of containment, and less violent expansions. The immediate structural damage inflicted on WTC 1 within the first few seconds upon impact was due to the kinetic energy being absorbed by the building, and not by the ignited fuel.  --Lambiam 21:44, 7 September 2022 (UTC)

Even more of a reason why such distinctions are meaningless, and insistence otherwise only fuels the sort of misinformation that leads to nutjob 9/11 conspiracy theories. Debates over imprecise terms that are used differently in different context is not helpful. If the words fireball and explosion are not sufficiently brightline in distinction, and they are not, then it doesn't help to use them in this context when trying to elucidate the history of the event in question.--Jayron32 22:36, 7 September 2022 (UTC)

Your position is basically that the original question is too meaningless to be discussed. In any case, there was no sudden rapid destructive high-energy burst of expanding gas.  --Lambiam 07:58, 8 September 2022 (UTC)

My position is that there is a misconception leading to invalid conclusions; the idea that "there was no explosion" leads many to the conclusion that something about the narrative of the 9/11 events which is flawed, possibly faked. Those conclusions are wrong, and the "there was no explosion" narrative (which rests not on data, science, or factual evidence, but rather linguistic ambiguity) is distracting from the discussion, and instead of focusing on "what is an explosion", we should be focusing the discussion on "what was it about the plane hitting the building that may have led to the follow-on events, such as the building collapse". One cannot meaningfully answer a question built on false premises. Instead, we need to provide clarification and seek further information as to what the question asker wants to know. See XY problem, which explains the situation thusly "The XY problem is a communication problem encountered in help desk, technical support, software engineering, or customer service situations where the question is about an end user's attempted solution (Y) rather than the root problem itself (X)." In this case the Y (attempted solution) which is asking about the nature of the distinction between a fireball/explosion (an issue of semantics and ambiguity) is instead a distraction from the root problem, which is a better understanding of what happened on the day. --Jayron32 10:54, 8 September 2022 (UTC)

I'm sorry that I tried to answer the OP's question without realizing it was built on false premises and that we instead should have answered another question, one that was not asked.  --Lambiam 22:05, 8 September 2022 (UTC)

No need to apologize, but in cases of plurium interrogationum, a false premise leads to an unanswerable question. "On what day did you stop beating your wife?" is an unanswerable question if you did not ever actually beat your wife. --Jayron32 19:16, 12 September 2022 (UTC)

I didn't mean to lead anybody on with a false premise or anything like that, my apologies. My question was just in regards to something I had been confused over for quite some time and thought I should ask here for clarification. Hmm1994 (talk) 19:21, 12 September 2022 (UTC)

With fireballs there are circular motions discernable in the volume of them. Fireballs can be triggered by explosions, but regarding the present subject 'merely' is not a very adequate quantifier for comparing the two phenomenons. A crash collision alone will already break and crush materials apart as well as have many of the debris generated change their direction and speed from none to one. Explosions mimic the shape of fireballs if they are generating a lot of heavy smoke, but then, after an initial very short bright flash, what remains if not burning will be dark, or at least, opaque. --Askedonty (talk) 16:32, 11 September 2022 (UTC)

Since it's related to the present topic, I also have to ask: is it also true that this fireball/explosion/whatever was only present on the north face of the building where the plane entered? It's a little hard to tell from the footage we have of the first crash. Hmm1994 (talk) 19:06, 12 September 2022 (UTC)

I don't dare to answer, since I appear to have a hard time discerning false premises and therefore don't know whether this question too is built on false premises. Why don't you ask a question that addresses the root problem, which is a better understanding of what happened on the day?  --Lambiam 21:09, 12 September 2022 (UTC)

I'm not quite sure what you mean. The two questions I asked here (1. Whether it was an explosion or a fireball and 2. Whether it was only on one side of the building or not) are based off information that was given by you: "When the plane hit the North Tower, there was no explosion, merely a fireball emerging seconds later from the north side where the plane entered, away from the South Tower. --Lambiam 02:44, 25 July 2022 (UTC)" I even said so in my very first comment on this thread. Hmm1994 (talk) 21:28, 12 September 2022 (UTC)

I was advised that I should not have answered your first question because it is built on false premises. I was (and still am) unable to detect these false premises. Apparently, my false-premise detector is not in good working order. For that reason, I fear I may be equally unable to detect any false premises underlying this related question.  --Lambiam 23:20, 13 September 2022 (UTC)

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