John Cuthber

I have a bus to catch so I'm not going to waste much time on this now. OK, It's been a while- they building was hit by a building that was hit by a plane, rather than the building was hit by a plane. Like hat matters... The premise I'm working on is one of sudden major damage to the building. That's not false. Since I ruled out people as the setters of the explosives (because they would have been seen, I'n not asking who did it: I'm asking what did it? The tooth fairy is one option you might choose. And you tried to get away with pretending not to cherry pick the data.

I can only be bothered to point out a few of your errors at the moment " But the observed descent time for 8 stories was 0 percent greater than the computed free fall time for 8 stories.... and that's completely inconsistent with physical principles." Nope, not zero. Not measurably different from zero isn't the same thing.The internals structure wouldn't make much difference to the fall speed once it got underway. "There's simply no point during a natural progressive structural failure where the conditions required for free fall can arise. An explosion or other type of event must have occurred that was powerful enough to quickly remove support from beneath the the literally falling upper part of the building" Yes, you may recall that someone flew a plane into it, also you seem not to have understood the stuff about buckling. "No, that's where the NIST looked very carefully at the data for (about) 1.75 seconds to 4 seconds and said "it's in free fall", not me. " OK, it's NIST's graph, but it is the data you are using, so, in that sense it's "your" data, and it contradicts what you say. Do you not understand that the data only indicate very close to "free fall", for about half the time? They do so at the point where the building would be expected to be in near free fall because the structure isn't built to have a building dropped on it. The resistance it offers to that huge impact load is small, compared to the weight of the building. Essentially, once the building starts to fall, it hardly notices the structure under it. "No, I chose to look at an aspect of the NIST analysis that describes a physical impossibility." Nope, the physics is fine. The problem is your lack of understanding. "No cherry picking. Like I said, I chose to look at an aspect of the NIST analysis " Nonsense, the choice of the few seconds in the middle of the graph where the building is in near free fall but ignoring the start and finish, is clearly cherry picking the data. Did you think you would get away with that? "As anyone who owns an old television set knows, ..... it's done by attaching precision timed high-explosives/cutter charges to the steelwork." And, as anyone who has watched the TV shows knows, it takes a lot of time, and expertise to place those charges- not to mention pre cutting through the structure, drilling damned great holes in the concrete etc. Are you saying the tooth fairy did it? Because humans couldn't have- they would have been spotted. And finally (hopefully) The thread title asks Why was it so fast? well, it wasn't fast so there's nothing to answer.

Sounds like a good idea. Incidentally, I'm not sure how rich they would be. It's widely touted that the UK has to maintain low taxation to stop those in the finance industry buggering off. Well, for a start, most of them wouldn't get far without a translator but that's not the important point. The implication of that "threat" is that the finance industry is "The Big Industry" in the UK. Everyone "knows" that the UK's manufacturing industry went down the toilet in about 1970. But that's a misrepresentation (no prizes for guessing who is maintaining it, but here's a hint- it's why I don't wish to be ruled from Westminster) Here's the figures from wiki "In 2011 the UK manufacturing sector generated approximately £140,539 million in gross value added" "The UK financial services industry added gross value of £116,363 million to the UK economy in 2011" from http://en.wikipedia.org/wiki/Economy_of_the_United_Kingdom Yep Our old, tired, run-down manufacturing industry still makes more money than the financial sector. Incidentally, re. "After all the Geordies are well known as drunken misogynists, with poor diets, whose speech is unintelligible. - so they are obviously Scottish already." Have you met the Mancs, the Scousers and the Brummies?

I certainly hadn't forgotten the crusades- I thought about including them as an example of why it's roughly as logical to say that "Christians should kill Muslims" as it is that "Muslims should kill Jews".but that seemed to be complicating the issue. There's little if any doubt that Hamas are a bunch of shits. However they are a bunch of shits who were (more or less) elected. You need to realise that the people who voted for them thought they were the "best available" option. If someone puts you in a position where Hamas look like a good idea, then your real enemy is whoever put you in that position in the first place.

"he strength of buckling columns (whether buckled one at a time or all at once) doesn't just go from 100% to 0% when they fail, " Actually, it almost does. That's the basis of this widely used model. "In 1757, mathematician Leonhard Euler derived a formula that gives the maximum axial load that a long, slender, ideal column can carry without buckling. An ideal column is one that is perfectly straight, homogeneous, and free from initial stress. The maximum load, sometimes called the critical load, causes the column to be in a state of unstableequilibrium;" from wiki http://en.wikipedia.org/wiki/Buckling There really is a "switch" from the stable to unstable state. And impact loading will help too. I presume that you don't have enough grounding in engineering or physics to have realised that before. The problem you have is that you keep arguing against yourself. You say "the falling is too fast" and "the falling is too slow". You keep trying to pretend that a building should stay still for a little over a second after the "explosion" destroys the structure. And then it suddenly goes into free fall. That only happens in scenarios like the critter in the first cartoon here http://en.wikipedia.org/wiki/Cartoon_physics#mediaviewer/File:Cartoon_physics_WikiWorld.png

Can we move the border down to about Birmingham, then declare independence? There are plenty of people in the North of England who have no more desire to be ruled from Westminster than the Scots have.

It's not clear to me whether the translation would be because I don't know what word you are seeking to translate What does the word mean?

OK, so have a look at your own post here http://www.scienceforums.net/topic/62527-the-collapse-of-wtc7-why-was-it-so-fast/?p=793409 where you look very carefully at the data for (about)1.75 seconds to 4 seconds and say "it is in free fall". But you ignore the same data for the first second or so. In that second, the data clearly show that the building is falling, but not in free fall. So you have done essentially what you described as absurd. Well, you are right, cherry picking like that is absurd. So why is it the only way you can support your assertion? How come the building starts falling more slowly than free fall, then builds up ? If there was an explosion, the building would have nothing holding it up and would, from the outset, be in free fall. It clearly was not - your own graphs and data show that. For the first second or so (and that's a long time in explosives work) it falls too slowly. So, as I said, this whole thread is like a discussion of the assassination of Stalin in '43 You are trying to "explain" something which never actually happened.

It's not just a matter of muddling the books or wrong wording is it? It's more like saying that, because the Pope (Innocent III) said that the Jews were the enemies of Christians, it is part of the Christian scripture.

Well, you may not think you are muddled, but yet you muddled the charter and the constitution. Then you muddled the Koran with the hadith. I didn't read it, because I don't disagree with your assertion of what it says. And there are those in Israel with comparable views , the other way round. So what? There are nutters on both sides. The interesting question is how come one lot got elected. Well, at the moment the people doing the best job of recruiting to Hamas, are the Israelis.

That's good. Now, would you like to acknowledge my point. Here it is again, in case you missed it. The other issue that gets glossed over is that they didn't exhibit free fall. "The observed descent time of the upper 18 stories of the north face of WTC 7 (the floors clearly visible in the video evidence) was 40 percent greater than the computed free fall time." This whole thread is like a discussion of how Stalin was assassinated in 1943.

I think you may be getting muddled I can find plenty of references that say things like this "On March 30, 2007, Hamas spokesman Ismail Radwan said on Palestinian Authority television The Hour [resurrection] will not take place until the Muslims fight the Jews and the Muslims kill them, and the rock and the tree will say: "Oh, Muslim, servant of God, there is a Jew behind me, kill him!" But none which actually cite the Q'uran Can you? Also, you seem to have mistaken Hamas' policies for the policies of the whole Palestinian people.

Use a steam bath or Bain Marie for the last bit of the evaporation (though it will take a long time).

Aemilius, You seem to have missed this, so I will repeat it for you.

Just out of Idle curiosity, why on earth do you want to know the input impedance of a TV?

" It is in their constitution and their 'holy' book after all." No it isn't. http://en.wikipedia.org/wiki/Constitution_of_Medina And it may be in the minds of some Palestinians, but perhaps that's only fair since the destruction of Palestine is the intention of some Israelis. Can we nail the "Hamas puts its citizens in the way off the rockets" idea once and for all? The Gaza strip is so crowded that there's practically nowhere you could drop a shell without hitting civilians. Israel knows that.

I'm sorry, but you will have to explain that. It does not make sense because it is not connected to the text which you quoted.

At the risk of being shouted at for anthropomorphising... If there were no rules the universe would have to decide what to do in each and every case. When a billiard ball hit another the Universe would have to make up its own mind about what to do.- Should it stop and transfer energy and momentum to the second ball? Should they both travel on in the same direction, but with reduced speed? Should they turn into bananas? Having a set of "rules" is the simplest solution. That's not strictly a reason- the Universe could be as complex as it wanted , and the rules could be obtuse too- (Momentum conservation- except on Tuesdays, when there's an R in the month). But those sorts of complexity would require the Universe to have some sort of decision making ability (and a calendar in the case I put forward) A few simple rules seems intrinsically easier to maintain than the alternative. As with people, the rules are there to save you having to think.

Impedance matching doesn't just affect power transfer. If the antenna, cable, and preamp don't all have reasonably matched impedances, then you would get reflection and, potentially, ghosting on the image. I have seen antenna inputs where the first thing the signal meets is a 50 ohm resistor to define the input impedance, followed by a fast, high Z, buffer amp. If you can open up the TV and check to see if there's a 75 ohm resistor, then you don't need to make the measurement.

"you first mark the beginning point in the frame or cabin & then after displacement. You mark the finishing point & after event you measure distance between these two point instantly. & that length is displacement." I may be mistaken but I think that, according to SR, "instantly" doesn't have a defined meaning for events separated in space. So, at best, you have ignored one of the axioms of SR, in order to prove it false. That's not logical.

You have just defined the police of most countries as terrorists. Was that your intention? (For example) http://en.wikipedia.org/wiki/Death_of_Mark_Duggan http://en.wikipedia.org/wiki/Shooting_of_Michael_Brown http://en.wikipedia.org/wiki/Sharpeville_massacre I'm not saying it's a good state of affairs, but people identified as "traitors" in wars tend to get very rough justice. The most successful way to stop this would be to end the war. Incidentally, the Palestinian people might be able to count, in which case they will find that Hamas has executed 18 of their people while the Israelis have killed over a hundred times more, many of them women and children. That still leaves it pretty clear who "the enemy" are.

Are you sure? I think the ratio of successive terms of the series trends to phi. no matter what the initial terms are.

An option for "respiration" would be the reaction of (metallic) iron with sulphate. Whenever that ice fell out of the sky, it would have picked up some SOx on the way down.

Re the first, nope, I don't. And the second doesn't mean anything. It's not freedom which leads people to terrorism, it's oppression.

It's not a language I know but if this example http://en.wikipedia.org/wiki/Java_(programming_language)#Hello_world is right then you need to use quote marks " rather than apostrophes ' to denote string litterals