It's a linear increase in force as each subsequent floor collapses.
No, it most certainly isn't. I'm shocked this is the level of intelligence we've actually got on Slashdot. The collapse loses energy, force and momentum as it goes, and it is slowed even more by the compacting of the debris. To say that an object can collide with another and for there to be no loss of force, momentum or acceleration is just so ignorant and stupid it defies belief.
I believe that the report cited it as being 40% that of freefall
Repeating this parrot fashion won't make it true. The report is wrong, because what they say in there has never been practically proven either in any observed collapses in the past, or in simulations with models. They can say what they like, but until they practically demonstrate it it is still fundamentally flawed. The rate of fall will slow dramatically as the collapse progresses until it stops, and that will leave much of the building intact.
As c6gunner pointed out, demolition crews don't do this because it leaves a lot up to chance, and they want the demolition to go as smoothly as possible.
No. Demolition companies collapse buildings floor by floor in that manner because it is the only way of completely collapsing a building that tall.
the question is whether the floor below can withstand the IMPACT of that much weight. The answer, as any engineer, and even some high school physics students can tell you, is not a chance.
No. The question is whether the floors (notice the plural there) can withstand the impact of that, because the debris and floors compacts together to withstand the collapse, and the further the collapse progress the greater the reactive force from the debris and floors below to withstand the collapse. Like I said. Try this with some Lego, a scale model or anything to give yourself some actual practical experience.
The building was already inherently unstable due to the the heat expansion of vertical columns
I'm just wondering how destabilisation and the effect of heat on the eightieth floor of a building affects the structural integrity of unaffected floors at the fortieth or the tenth floor, because this is what is required to completely collapse a building. The firefighters knew this fact, which is why they had no worries at all about going into the building and setting up a base on the unaffected floors below.
Try this with a model, any time. You will never be able to collapse a building as tall as the WTC buildings by doing that, which is probably why we've never seen a scale model demonstration of the shit that that report says is true.
Believe what you like, but your ignorance on the matter, in addition to your insistence that you are correct, makes you a card carrying conspiracy theorists.
Sweetheart, you have never seen a building collapse in your life - not even a model. If you think this is a conspiracy theory then that's fine, but that's something you're going to have to deal with in your own mind. The questions still remain.
Why did you lie about not being a conspiracy theorist?
Hmmmmm, yer. I just wonder who the conspiracy theorists are really.
Anyway, any structural engineer can tell you that you're full of shit. There's more than enough kinetic energy in a building like WTC7 to guarantee a complete collapse once the mass starts moving.
More than enough kinetic energy where, and what mass starts moving? In what way does this utterly meaningless and non-defined statement pertain to WTC 7 or any of the other buildings? If anything is full of shit, it's that. You can't start a fire and/or structurally destabilise the top few floors in a multi-storey building and have it completely collapse the whole building. Fact. The greater number of structurally sound floors below are more than enough to dissipate any energy and momentum of such a collapse unless you destabilise the floors below (or they are already destabilised) in some way so they respond weakly. Try this on any model that you might care to build. Seriously.
The reason demolition teams normally get involved is simply because if you want a CONTROLLED demolition, you need to be careful about how you bring the building down.
Cause if I break your knee, you will fall if you can't support your weight with one knee.
Yer, because the weight and mass above is greater than the weight and mass below and will fall over because it has reached a tipping point. Obviously. However, the weight will not collapse the leg below my knee into a pulp into the floor. Everything above the knee will fall over and leave at least the foot relatively intact.
If there are 110 of you and #30 from the top has his knee broken, he and everyone above him falls on #31 from the top and if he's unable to support that weight then he falls as well and #32, who isn't much more likely going to support the weight any more than #31 so he collapses.
The momentum and energy of that collapse dissipates and slows as each person collapses until the collapse stops because there is less of you at the top than there is below. You'll be unlucky if more than half of that structure isn't left. However, since you're talking about a structure of people then it's all rather null and void, isn't it?
Do we really need to spoon feed this stuff to you or are you simply trolling?
I am astonished that this is the level of pure bile we're getting on Slashdot these days. If the above were the case then the demolition industry is wasting its money.
Here, let me put it in perspective for you: If you have a human pyramid of 6 people(3 on bottom, 2 in the middle, 1 on top) and you knock over the top person one of the people below it might also "collapse" with them
Yes you will, but this action will run out of energy pretty quickly, and will stop pretty quickly, and won't result in a cascade to the rest of the structure - unless the rest of the structure is completely unsound or has been made unsound in some way.
Now build a human pyramid consisting of 55 people(1,2,3,4,5,6,7,8,9,10) and make the row 3rd from the top collapse. There you have 6 people(1+2+3) falling on 4 people, there will likely be a collapse of the 4 people which will then be 10 people falling on the row of 5......and so on until all 55 people are on the ground.
This is a bogus argument, because the reason why this structure collapses is because a structure of a pyramid of people is unsound from the top to the bottom. It doesn't collapse because of the momentum of a collapse in the top half. If you tried to do this to the pyramid of Giza, bugger all would happen apart from a collapse of the top part of it. Using a pyramid as an example is also bogus, because there is less on the floor above than on the floor below. If you had an inverted pyramid, you might have a point, but you don't.
Now that is what happens if it's a pyramid, so if it were a straight vertical tower of people, if the 3rd row of people fell, then the 2 rows above them will also fall making the 4th row have to withstand far more momentum.
No, this would not happen at all. It doesn't pick up momentum. It actually loses energy and speed as it goes until it stops. I have never seen an increase in the weight of debris accelerating a collapse beyond the fall of gravity.
If you know anything about the people who break bricks in martial arts by putting a little space between each brick so that the momentum of the bricks above them will help break the ones below them
You'd have to have one extremely and dangerously unsound structure for this to be feasible and have any bearing, and even then, it would still be difficult because all the debris compacts into each other.
Sorry bro, I know you want to believe but this was just pure physics and there were no explosions HEARD when it happened.
I'm not sure what you think I want to believe, and I'm not interested in any explosions at all. I'm simply talking about how the mechanics of a collapse actually happens.
If you believe these physics are true then feel free to present your findings at a demolition conference somewhere. The industry will slash their costs like there's no fucking tomorrow!
The answer is that it didn't have to. When the upper floors gave way, they impacted the floors directly beneath them. The kinetic energy that is gained by those floors basically free falling 1 story down is immense
This has been repeated often, and is utterly bogus. No demolition team has ever turned up on site and said "Oh, we'll burn five stories in the top half of this fifty storey building and it will collapse". Never happened. Why? Because there is nowhere near enough energy for those floors to collapse all the floors below them, and the more floors below the fire that collapse the more compacted it all becomes and the more the energy dissipates slowing the whole process down until it stops.
Try this with any model, any time. You will never be able to achieve what you're saying. Hell, if what you say is true than the demolition industry could really cut their costs!
The big thing is that by this point, the upper floors have gained such an incredible amount of momentum from their falling, which is only increasing with their mass
No, because it's losing energy dramatically as it goes, not picking it up. Try this with any kind of model over six stories. You will never precipitate a complete collapse.
I have never ever seen anything where increasing the weight of debris accelerates a collapse beyond the effect of gravity. If this is your physics theory then I recommend trying some practical.
There's really no point in furthering this discussion until we get past the mental deficiency that allows you to believe that all of the steel in the entire building had to have melted (or even just been touched by fire) in order for the entire structure to collapse.
I don't believe I've said that all the steel needed to melt at all. This is something you're assuming - for some reason.
However, to get a complete collapse of a whole building that large you have to have destabilised large parts of it at various intervals to ensure that it all goes straight down and not a trace of the structure is left. All the floors below the fire have to be destabilised in some fundamental way to ensure this happens. No demolition company has ever turned up on site and said "Oh, we'll burn five storeys in the top half of this fifty storey building and it will all go down". The entire building needs to be accounted for.
You've offered no explanation as to how all the floors, most of which were completely untouched, below the few floors that were affected by fire became so structurally unsound that they were able to collapse in. Unless this happens, you simply don't have enough energy to precipitate a full collapse from the action of a few floors at the top of the building collapsing into those below. You will still get at least some of the building intact.
Why do you believe this must be true?
I don't. I'm asking the question as to what caused all the floors to completely collapse.
Pancaking is what the controlled demolition people deliberately cause ('Implosion' is an incorrect media term) and a fairly common mode of failure during construction.
No. The demolition industry avoids the pancaking of floors, because they want an ordered collapse of each individual floor, or at defined levels, to avoid floors completely pancaking into each other and completely dissipating the energy of the demolition. Thus, you see one floor going, and then the floor below a few milliseconds after to avoid the floor above completely collapsing into the floor below to avoid the collapse from being halted and to avoid debris being spread.
You have to do a controlled collapse of each floor at various intervals to make sure the building completely collapses. If you don't, and all you have are a few weakened floors above collapsing (pancaking) on themselves and on to the floors below, then the floors below will simply absorb the energy, the collapsed floors will fall outwards and keep at least some of the building intact. That's why no building above six stories has completely collapsed of its own accord. There's simply too much of it, unless you've weakened the floors at every level. Seriously. Try this with any kind of model any time. It will run out of steam.
It only takes one floor failing to take everything down below the original failure.
Hmmmmmmmmmmmmmmmmm. If you destabilise one floor there is nowhere near enough energy to collapse the whole building when the rest of it is still largely intact. That's why any demolition will demolish a building bit by bit at specific times and at given floor levels to make sure the whole thing goes straight down.
It's primary characteristics are complete destruction of the affected area and falling straight down.
Fucking hell. Reply when you know what you're talking about. Please. A shorter building is more prone to a complete collapse because there is, ummmmmmm, less of it. A fire in a few floors in a shorter building will proportionately take up more of the building and destabilise the building as a whole more. A fire in two floors in a five story building is serious. A fire in two floors in a twenty story building will not destabilise all of it, although it is still obviously a problem.
Do you have examples of this? Keep in mind, they should be as similar to the Twin Towers as possible. Personally, I think you're going to have some serious problems finding comparable data points. Good luck...
Sorry sweetie. The onus is on you. No building above six stories has ever completely collapsed of its own accord because of what I described above, and if all you have as a comeback is "The WTC Towers are different to other buildings", then you have a problem. The question I have is, why are the WTC buildings totally different to every other building that has ever existed and why would a fire in the eightieth floor destabilise everything down to ground floor cascading in a complete collapse to untouched floors? I'm still waiting.
Right. The Windsor building had a much smaller floor area than the Twin Towers. No surprises here.
Errrr, yer. So why did a much larger building where large parts of it were untouched by fire collapse?
Ah-ha! I have a question: why did you lie to me about not being a conspiracy theorist?
Because it's all in your mind sweetie. You don't like what is being asked here, and you're assuming I have some government conspiracy packed away when all I'm doing is asking the questions.
Only conspiracy theorists parrot this asinine claim that "all the steel" had to melt before the building could collapse.
Hmmmmmm. So why, exactly, were none of the buildings left standing when comparatively little of them were touched by fire? Why are none of the WTC buildings left standing, when collapses in other buildings have left at least some of the untouched structure? I have a feeling we'll be going around in circles over that one, and sorry, but no, asking that question does not dismiss it as a conspiracy theory.
I mean, that statement of yours is ignorant on levels no man should ever reach.
That's a bold claim. Why exactly?
Do you understand why?
No. Feel free to fill me in, because you've come up with jack shit so far.
Huh? The point of a controlled demolition is to prevent damage to surrounding structures and allow machinery to clean up the mess quicker and cheaper than dismantling in place. Pancaking occurs in controlled demolitions.
Pfffffffffffffffffff. It's controlled and timed pancaking which allows the building to completely collapse. If you allow a tall building to pancake naturally via the top fllors collapsing then the floors below will simply collapse into each other and dissipate the energy. You won't get a complete collapse. Try it any time with a model, some Lego or some Meccano. You won't be able to do it.
There is no citation needed. Firefighters don't have too much fear of going into a multi-story building because the risk of collapse is not great. That's why firefighters, ummmm, you know, actually went in there as the fire raged. If there was a risk to them they wouldn't have gone in. That's based on years of experience.
I don't need any research to tell me that if you fly a large passenger airplane into a building then something really bad going to happen to it.
No shit?
As far as WTC7, I've seen a whole neighborhood burned down in less than an hour because of one house catching on fire
Yer, because, ummm, you know, the fires can actually spread because the buildings and the fires are at the same, ummm, level. This is clearly not the case here. The fires are several stories up, and the notion that a fire can spread from the top of a tall building to a much shorter building and completely demolish it is a huge, huge, huge stretch of logic.
I'm just asking the questions. Quite clearly, a lot of people really do not want to face trying to answer them logically.
I'm not a conspiracy theorist myself, but I have to laugh heartily at some of these debunkings. The Madrid Tower actually works against you here, and the cited articles actually admit it. For starters, the Madrid Tower is far shorter than the WTC buildings and is much more prone to a complete collapse, which is what we're talking about here. Collapses in taller buildings will tend to leave at least something intact because of pancaking. Secondly, look at the huge intensity of that fire relative to the size of the building itself. It encompassed the entire building:
That didn't happen in the WTC collapses. Alas, that debunking just raises far more questions than answers. You can't melt all the steel in a very large building to induce a complete collapse, especially not in the lower floors of a building where a fire rages multiple storeys up, and the building will not collapse completely when the upper floors collapse because the lower floors are still sound enough to keep at least something left standing.
The problem with that theory is that in a controlled demolition you destroy all they key points in a building to come up with an orderly collapse of each floor, and avoid pancaking. A fire simply wouldn't be able to destroy all the key points in a building like demolition would, and you would get pancaking which would dissipate the energy of the collapse. In short, you would still get at least some of the buildings still left standing.
I'm sorry, but buildings that large do not completely collapse like that due to fire. That's why firefighters had no fear whatsoever of going in there. You would have probably got at least half to three quarters of the buildings still left standing because fire would not destabilise and collapse every single part of the building. It's crucial to remember that absolutely nothing was left standing. It certainly wouldn't happen in two, or even three, buildings as well, as appears to be the case. The case of the seventh building is still very flimsy, and the whole thing hinges on the fires somehow spreading from other buildings. You can get simulations to say anything if you ask "What if?" for long enough, but that doesn't mean that it happened that way, and real-life experience tells us it probably didn't.
Were the buildings demolished? It's certainly possible, and the manner of the collapse(s) were mighty suspicious, but I have never seen any concrete evidence for that, as much as we might want to get ahead of ourselves. Is there some government conspiracy? Possible, but again, people always seem to jump several steps ahead when they talk about that and we still have no evidence at all. Is the above a conspiracy theory? Nope. It's based on years of how large buildings have tended to collapse, and how they react to fire, and all I and others would like is a sensible conclusion which takes that into account. Repeatedly saying "The buildings collapsed due to fire" and coming up with a theory to fit the facts with nothing to back it up is never going to be good enough.
Cynically, all this report seems to be is a knee-jerk response to the really big elephant in the room - the complete collapse of WTC 7 - discussion of which has been doing the rounds for a while, and has gained some traction.
Sun pushed hyperthreading to its limits to achieve very impressive energy efficiency for certain niche workloads with its Niagra CPUs and derivatives. (IIRC, up to 128 threads per chip.)
Unfortunately those are very, very, very, very, very niche workloads. Your workloads have to be insanely parallel and each thread very independent of others so that you have little that is blocking. In short, Niagra is just marketing.
Solaris just works and its made for servers. Linux seems always beta quality with its cutting edgness and is desktop oriented. I would not trust my job to it unless its Debian or RHES which costs $$$ as cutting edge features are not needed on a mission critical server.
This is such a sad thing to say now it's just not even funny, and I feel mighty sorry for the Sun reps and consultants who still have to deliver this very, very tired line of a 'beta' quality Linux and Solaris being a 'real' Unix OS. Sad. Plain sad. After the dot com boom at the turn of this century, and after cheaper x86 servers and Linux started delivering a lot more performance than Sun's 'quality' hardware, anyone who cared about their job and performance moved. I really don't know what it will take for those people to go back.
Certainly, if you were an admin running quite a bit of open source software such as Zope, Python etc., and you were *trying* to run it on Solaris, you switched to Linux years ago because developers didn't give a shit about a proprietary Unix running on proprietary hardware where they couldn't work out what was happening. Too expensive to develop for, too expensive to troubleshoot. These are the people OpenSolaris is trying to get back, and it has long since been too late. Many universities and educational establishments fitted that bill back then, and they moved.
Linux is simply a far better Unix. Open source developers develop for a Linux platform first, you find problems and solutions pretty much instantly when you run Linux as your platform, and that is the kind of 'support' Sun just cannot match. Any Linux distribution is also far less of a PITA to install, to admin and especially to install software for.
Solaris is a *real* Unix OS because you need a consultant to sit with it on site for several days to get it to do anything. That is how Solaris is designed, from the ludicrous time needed to install the OS itself to the time needed to install software. It is designed to eat $$$ and £££ in support costs. That's the bottom line.
Solaris scales far better than any BSD or Linux distro out there.
Another sad and tired line from the Sun rep handbook. That's just not the experience that most people are getting, and 'scalability' so misused these days it's hilarious.
Ask any *real* Unix admin who uses both and more than likely they will say Linux is great for small jobs but Solaris is king for anything else.
Sad. There's that 'real' word again that you get from Sun reps and consultants out there. Do you not think people are getting 'real' work done with their Linux systems? Is that so incredible? Do you not think 'real' Unix admins want to log into a shell that doesn't suck and has actually improved since about 1988?
As for online video, why the fuck is every sonofabitch out there making their own fucking flash client for video? Video should be distributed in a proper file none of this "Compress->Re-encode/resample for flash->stream to my computer" bullshit...
Simple. Because there's no easy way of distributing video over the web, that's why. With Windows Media and Real you have to account for the version or plugin people are running, and it's a pain when you can just have the video appear within your browser quite easily. We have Ogg Vorbis and HTML 5, but there is little chance of Microsoft adopting that for obvious reasons. Bizarrely, even Nokia are against it, so we'll be stuck with Flash as a distribution medium as Microsoft and others fanny about trying to make their technology the standard...............again.
I've been weighing up whether to migrate from VMware Server for our limited set of operations and move to ESXi and then ESX. This has made up my mind now. I'd rather wait for the hype of virtualisation to really settle down, use it in a pretty limited capacity and then run more stuff on technology and a host system that gets it right - KVM and Linux. I don't care too much about waiting, because as far as I'm concerned this just isn't acceptable. Many organisations will be brought to their knees by something like this, and over something that is totally unnecessary as well. I could understand pretty much any other issue, but not this. Sorry VMware.
People who follow fads get what they deserve. If you have something on one server, and you know where it is even if it's hosted, then that is at least something. Backups are still important though, obviously. However, in a cloud it could be anywhere. If you lose one part of the cloud then your data is essentially useless. Backups become even more important.
The difference here is that KDE 4 offers the break that was promised, with compelling improvements that will actually make people want to use it. In the meantime, you could still use 3.5.x. OpenGL 3.0 is really just 2.2, where people have no motivation whatsoever to move to it and deal with the same old drama. There is no reason to suppose things will get better in 3.1 or 3.2.
The whole speculation on Core Location comes simply from the URL having clbl in it, which supposedly stands for Core Location Black List. There is no other evidence provided that this is only what it does, nor does it mean that Apple can't use it in some other form or that they're not working on a set of black listed applications they can retrospectively turn off. Apple have already shown how developer friendly they are by pulling applications from their store without warning.
Personally, I find a black list like this an exceptionally stupid and blunt way to deal with access to Core Location.
I might not have one of the lowest Slashdot IDs around, but I am absolutely astonished at some peoples' astonishment over this. DNS, by definition, is all about trusting the forwarders you are using or other DNS servers you are caching from and trusting the DNS server you use from there. That's where the problem is, so if people are shouting and screaming about trust now then it's all a bit late.
If your DNS server says that slashdot.org resolves to something other than 216.34.181.45 then that's where you're going to end up. There are also legitimate reasons why someone might want to do something like that, and it is part of the inherent flexibility that has made the internet and its technologies as ubiquitous and as well used as they are. No one said that there weren't downsides. If you locked everything down in the manner that some idiots will inevitably now talk about, shouting and squealing about financial institutions, then I'm willing yo bet that you will lose a good portion of the flexibility that makes the 'internet' actually work on a wide scale.
We are a 95% Linux site- servers and clients, and it is nearly impossible to find industry specific Linux applications. The kicker is- we would be happy with even CLOSED source, commercial applications.
For industry specific and niche applications it is doubtful whether you will ever get a set of open source applications for a lot of set purposes. What is required are reasonably straightforward development frameworks for application developers to pick up, create a wide variety of software and be able distribute those applications easily to you. Linux and open source software has various parts of this in place, but the main problems aren't being solved. If we get that then maybe open source developers from the Windows world will chime in as well and create a snowball effect.
What is needed is a COMPELLING, modern, cross-platform, open-source, GUI, business application development environment. It is 2008.
It has one. It's called Qt (yes, it works everywhere well on Linux, Unix, OS X and Windows), it really works and it even has a modern desktop environment developed with it called KDE with frameworks being developed that are trying to solve some of the more pressing problems we've had for years - easy desktop scripting and development, easy installation, integration of the OS with the desktop etc.
Unfortunately, the vast majority of the Linux companies seem to be fannying about with stuff that isn't going to work or move forwards this side of the next ice age.
Rather than moaning about the fact that other people aren't putting in the effort into pushing development frameworks forward to allow developers to create lots of great applications, and helping them distribute said applications to users, maybe IBM should, you know, put in a tiny percentage of its overall costs and resources and bloody well do it?
Even more ironic is the fact that Bob Sutor (I believe) is one of the open sorce people at IBM who has pontificated about the evils of OOXML and the promotion of ODF. Well Bob, applications rule and if you want to help out, rather than lobbying the mess that is the ISO process and moaning in blogs, get out there and help produce some kick-ass ODF-using applications that people feel that they just have to use above Microsoft Office. No, creating yet another version of Open Office, but proprietary, and calling it Symphony, is not the answer. Meanwhile, as the main problems don't get solved, he then talks bullshit about cloud computing, that huge bullshit about how operating systems are less visible and matter less and software as a service.
The open source world is full of armchair moaners willing to pontificate about the deficiencies of Linux and open source software as a platform. Worryingly, these are sometimes quite large companies who profess to use Linux and open source software as a main source of income. They might moan about the current situation, but IBM's past history with OS/2 and Windows shows that they still have no clue whatsoever what needs solving.
Slashdot Mirror
No, it most certainly isn't. I'm shocked this is the level of intelligence we've actually got on Slashdot. The collapse loses energy, force and momentum as it goes, and it is slowed even more by the compacting of the debris. To say that an object can collide with another and for there to be no loss of force, momentum or acceleration is just so ignorant and stupid it defies belief.
Repeating this parrot fashion won't make it true. The report is wrong, because what they say in there has never been practically proven either in any observed collapses in the past, or in simulations with models. They can say what they like, but until they practically demonstrate it it is still fundamentally flawed. The rate of fall will slow dramatically as the collapse progresses until it stops, and that will leave much of the building intact.
No. Demolition companies collapse buildings floor by floor in that manner because it is the only way of completely collapsing a building that tall.
No. The question is whether the floors (notice the plural there) can withstand the impact of that, because the debris and floors compacts together to withstand the collapse, and the further the collapse progress the greater the reactive force from the debris and floors below to withstand the collapse. Like I said. Try this with some Lego, a scale model or anything to give yourself some actual practical experience.
I'm just wondering how destabilisation and the effect of heat on the eightieth floor of a building affects the structural integrity of unaffected floors at the fortieth or the tenth floor, because this is what is required to completely collapse a building. The firefighters knew this fact, which is why they had no worries at all about going into the building and setting up a base on the unaffected floors below. Try this with a model, any time. You will never be able to collapse a building as tall as the WTC buildings by doing that, which is probably why we've never seen a scale model demonstration of the shit that that report says is true.
Sweetheart, you have never seen a building collapse in your life - not even a model. If you think this is a conspiracy theory then that's fine, but that's something you're going to have to deal with in your own mind. The questions still remain.
Hmmmmm, yer. I just wonder who the conspiracy theorists are really.
More than enough kinetic energy where, and what mass starts moving? In what way does this utterly meaningless and non-defined statement pertain to WTC 7 or any of the other buildings? If anything is full of shit, it's that. You can't start a fire and/or structurally destabilise the top few floors in a multi-storey building and have it completely collapse the whole building. Fact. The greater number of structurally sound floors below are more than enough to dissipate any energy and momentum of such a collapse unless you destabilise the floors below (or they are already destabilised) in some way so they respond weakly. Try this on any model that you might care to build. Seriously.
No shit?
Yer, because the weight and mass above is greater than the weight and mass below and will fall over because it has reached a tipping point. Obviously. However, the weight will not collapse the leg below my knee into a pulp into the floor. Everything above the knee will fall over and leave at least the foot relatively intact.
The momentum and energy of that collapse dissipates and slows as each person collapses until the collapse stops because there is less of you at the top than there is below. You'll be unlucky if more than half of that structure isn't left. However, since you're talking about a structure of people then it's all rather null and void, isn't it?
I am astonished that this is the level of pure bile we're getting on Slashdot these days. If the above were the case then the demolition industry is wasting its money.
Yes you will, but this action will run out of energy pretty quickly, and will stop pretty quickly, and won't result in a cascade to the rest of the structure - unless the rest of the structure is completely unsound or has been made unsound in some way.
This is a bogus argument, because the reason why this structure collapses is because a structure of a pyramid of people is unsound from the top to the bottom. It doesn't collapse because of the momentum of a collapse in the top half. If you tried to do this to the pyramid of Giza, bugger all would happen apart from a collapse of the top part of it. Using a pyramid as an example is also bogus, because there is less on the floor above than on the floor below. If you had an inverted pyramid, you might have a point, but you don't.
No, this would not happen at all. It doesn't pick up momentum. It actually loses energy and speed as it goes until it stops. I have never seen an increase in the weight of debris accelerating a collapse beyond the fall of gravity.
You'd have to have one extremely and dangerously unsound structure for this to be feasible and have any bearing, and even then, it would still be difficult because all the debris compacts into each other.
I'm not sure what you think I want to believe, and I'm not interested in any explosions at all. I'm simply talking about how the mechanics of a collapse actually happens.
If you believe these physics are true then feel free to present your findings at a demolition conference somewhere. The industry will slash their costs like there's no fucking tomorrow!
This has been repeated often, and is utterly bogus. No demolition team has ever turned up on site and said "Oh, we'll burn five stories in the top half of this fifty storey building and it will collapse". Never happened. Why? Because there is nowhere near enough energy for those floors to collapse all the floors below them, and the more floors below the fire that collapse the more compacted it all becomes and the more the energy dissipates slowing the whole process down until it stops.
Try this with any model, any time. You will never be able to achieve what you're saying. Hell, if what you say is true than the demolition industry could really cut their costs!
No, because it's losing energy dramatically as it goes, not picking it up. Try this with any kind of model over six stories. You will never precipitate a complete collapse.
I have never ever seen anything where increasing the weight of debris accelerates a collapse beyond the effect of gravity. If this is your physics theory then I recommend trying some practical.
I don't believe I've said that all the steel needed to melt at all. This is something you're assuming - for some reason.
However, to get a complete collapse of a whole building that large you have to have destabilised large parts of it at various intervals to ensure that it all goes straight down and not a trace of the structure is left. All the floors below the fire have to be destabilised in some fundamental way to ensure this happens. No demolition company has ever turned up on site and said "Oh, we'll burn five storeys in the top half of this fifty storey building and it will all go down". The entire building needs to be accounted for.
You've offered no explanation as to how all the floors, most of which were completely untouched, below the few floors that were affected by fire became so structurally unsound that they were able to collapse in. Unless this happens, you simply don't have enough energy to precipitate a full collapse from the action of a few floors at the top of the building collapsing into those below. You will still get at least some of the building intact.
I don't. I'm asking the question as to what caused all the floors to completely collapse.
No. The demolition industry avoids the pancaking of floors, because they want an ordered collapse of each individual floor, or at defined levels, to avoid floors completely pancaking into each other and completely dissipating the energy of the demolition. Thus, you see one floor going, and then the floor below a few milliseconds after to avoid the floor above completely collapsing into the floor below to avoid the collapse from being halted and to avoid debris being spread.
You have to do a controlled collapse of each floor at various intervals to make sure the building completely collapses. If you don't, and all you have are a few weakened floors above collapsing (pancaking) on themselves and on to the floors below, then the floors below will simply absorb the energy, the collapsed floors will fall outwards and keep at least some of the building intact. That's why no building above six stories has completely collapsed of its own accord. There's simply too much of it, unless you've weakened the floors at every level. Seriously. Try this with any kind of model any time. It will run out of steam.
Hmmmmmmmmmmmmmmmmm. If you destabilise one floor there is nowhere near enough energy to collapse the whole building when the rest of it is still largely intact. That's why any demolition will demolish a building bit by bit at specific times and at given floor levels to make sure the whole thing goes straight down.
That's why you bring in a demolition company.
Fucking hell. Reply when you know what you're talking about. Please. A shorter building is more prone to a complete collapse because there is, ummmmmmm, less of it. A fire in a few floors in a shorter building will proportionately take up more of the building and destabilise the building as a whole more. A fire in two floors in a five story building is serious. A fire in two floors in a twenty story building will not destabilise all of it, although it is still obviously a problem.
Sorry sweetie. The onus is on you. No building above six stories has ever completely collapsed of its own accord because of what I described above, and if all you have as a comeback is "The WTC Towers are different to other buildings", then you have a problem. The question I have is, why are the WTC buildings totally different to every other building that has ever existed and why would a fire in the eightieth floor destabilise everything down to ground floor cascading in a complete collapse to untouched floors? I'm still waiting.
Errrr, yer. So why did a much larger building where large parts of it were untouched by fire collapse?
Because it's all in your mind sweetie. You don't like what is being asked here, and you're assuming I have some government conspiracy packed away when all I'm doing is asking the questions.
Hmmmmmm. So why, exactly, were none of the buildings left standing when comparatively little of them were touched by fire? Why are none of the WTC buildings left standing, when collapses in other buildings have left at least some of the untouched structure? I have a feeling we'll be going around in circles over that one, and sorry, but no, asking that question does not dismiss it as a conspiracy theory.
That's a bold claim. Why exactly?
No. Feel free to fill me in, because you've come up with jack shit so far.
Pfffffffffffffffffff. It's controlled and timed pancaking which allows the building to completely collapse. If you allow a tall building to pancake naturally via the top fllors collapsing then the floors below will simply collapse into each other and dissipate the energy. You won't get a complete collapse. Try it any time with a model, some Lego or some Meccano. You won't be able to do it.
There is no citation needed. Firefighters don't have too much fear of going into a multi-story building because the risk of collapse is not great. That's why firefighters, ummmm, you know, actually went in there as the fire raged. If there was a risk to them they wouldn't have gone in. That's based on years of experience.
No shit?
Yer, because, ummm, you know, the fires can actually spread because the buildings and the fires are at the same, ummm, level. This is clearly not the case here. The fires are several stories up, and the notion that a fire can spread from the top of a tall building to a much shorter building and completely demolish it is a huge, huge, huge stretch of logic.
I'm just asking the questions. Quite clearly, a lot of people really do not want to face trying to answer them logically.
I'm not a conspiracy theorist myself, but I have to laugh heartily at some of these debunkings. The Madrid Tower actually works against you here, and the cited articles actually admit it. For starters, the Madrid Tower is far shorter than the WTC buildings and is much more prone to a complete collapse, which is what we're talking about here. Collapses in taller buildings will tend to leave at least something intact because of pancaking. Secondly, look at the huge intensity of that fire relative to the size of the building itself. It encompassed the entire building:
http://www.911myths.com/html/madrid_windsor_tower.html
That didn't happen in the WTC collapses. Alas, that debunking just raises far more questions than answers. You can't melt all the steel in a very large building to induce a complete collapse, especially not in the lower floors of a building where a fire rages multiple storeys up, and the building will not collapse completely when the upper floors collapse because the lower floors are still sound enough to keep at least something left standing.
The problem with that theory is that in a controlled demolition you destroy all they key points in a building to come up with an orderly collapse of each floor, and avoid pancaking. A fire simply wouldn't be able to destroy all the key points in a building like demolition would, and you would get pancaking which would dissipate the energy of the collapse. In short, you would still get at least some of the buildings still left standing.
I'm sorry, but buildings that large do not completely collapse like that due to fire. That's why firefighters had no fear whatsoever of going in there. You would have probably got at least half to three quarters of the buildings still left standing because fire would not destabilise and collapse every single part of the building. It's crucial to remember that absolutely nothing was left standing. It certainly wouldn't happen in two, or even three, buildings as well, as appears to be the case. The case of the seventh building is still very flimsy, and the whole thing hinges on the fires somehow spreading from other buildings. You can get simulations to say anything if you ask "What if?" for long enough, but that doesn't mean that it happened that way, and real-life experience tells us it probably didn't.
Were the buildings demolished? It's certainly possible, and the manner of the collapse(s) were mighty suspicious, but I have never seen any concrete evidence for that, as much as we might want to get ahead of ourselves. Is there some government conspiracy? Possible, but again, people always seem to jump several steps ahead when they talk about that and we still have no evidence at all. Is the above a conspiracy theory? Nope. It's based on years of how large buildings have tended to collapse, and how they react to fire, and all I and others would like is a sensible conclusion which takes that into account. Repeatedly saying "The buildings collapsed due to fire" and coming up with a theory to fit the facts with nothing to back it up is never going to be good enough.
Cynically, all this report seems to be is a knee-jerk response to the really big elephant in the room - the complete collapse of WTC 7 - discussion of which has been doing the rounds for a while, and has gained some traction.
Unfortunately those are very, very, very, very, very niche workloads. Your workloads have to be insanely parallel and each thread very independent of others so that you have little that is blocking. In short, Niagra is just marketing.
This is such a sad thing to say now it's just not even funny, and I feel mighty sorry for the Sun reps and consultants who still have to deliver this very, very tired line of a 'beta' quality Linux and Solaris being a 'real' Unix OS. Sad. Plain sad. After the dot com boom at the turn of this century, and after cheaper x86 servers and Linux started delivering a lot more performance than Sun's 'quality' hardware, anyone who cared about their job and performance moved. I really don't know what it will take for those people to go back.
Certainly, if you were an admin running quite a bit of open source software such as Zope, Python etc., and you were *trying* to run it on Solaris, you switched to Linux years ago because developers didn't give a shit about a proprietary Unix running on proprietary hardware where they couldn't work out what was happening. Too expensive to develop for, too expensive to troubleshoot. These are the people OpenSolaris is trying to get back, and it has long since been too late. Many universities and educational establishments fitted that bill back then, and they moved.
Linux is simply a far better Unix. Open source developers develop for a Linux platform first, you find problems and solutions pretty much instantly when you run Linux as your platform, and that is the kind of 'support' Sun just cannot match. Any Linux distribution is also far less of a PITA to install, to admin and especially to install software for.
Solaris is a *real* Unix OS because you need a consultant to sit with it on site for several days to get it to do anything. That is how Solaris is designed, from the ludicrous time needed to install the OS itself to the time needed to install software. It is designed to eat $$$ and £££ in support costs. That's the bottom line.
Another sad and tired line from the Sun rep handbook. That's just not the experience that most people are getting, and 'scalability' so misused these days it's hilarious.
Sad. There's that 'real' word again that you get from Sun reps and consultants out there. Do you not think people are getting 'real' work done with their Linux systems? Is that so incredible? Do you not think 'real' Unix admins want to log into a shell that doesn't suck and has actually improved since about 1988?
Simple. Because there's no easy way of distributing video over the web, that's why. With Windows Media and Real you have to account for the version or plugin people are running, and it's a pain when you can just have the video appear within your browser quite easily. We have Ogg Vorbis and HTML 5, but there is little chance of Microsoft adopting that for obvious reasons. Bizarrely, even Nokia are against it, so we'll be stuck with Flash as a distribution medium as Microsoft and others fanny about trying to make their technology the standard...............again.
I've been weighing up whether to migrate from VMware Server for our limited set of operations and move to ESXi and then ESX. This has made up my mind now. I'd rather wait for the hype of virtualisation to really settle down, use it in a pretty limited capacity and then run more stuff on technology and a host system that gets it right - KVM and Linux. I don't care too much about waiting, because as far as I'm concerned this just isn't acceptable. Many organisations will be brought to their knees by something like this, and over something that is totally unnecessary as well. I could understand pretty much any other issue, but not this. Sorry VMware.
People who follow fads get what they deserve. If you have something on one server, and you know where it is even if it's hosted, then that is at least something. Backups are still important though, obviously. However, in a cloud it could be anywhere. If you lose one part of the cloud then your data is essentially useless. Backups become even more important.
The difference here is that KDE 4 offers the break that was promised, with compelling improvements that will actually make people want to use it. In the meantime, you could still use 3.5.x. OpenGL 3.0 is really just 2.2, where people have no motivation whatsoever to move to it and deal with the same old drama. There is no reason to suppose things will get better in 3.1 or 3.2.
The whole speculation on Core Location comes simply from the URL having clbl in it, which supposedly stands for Core Location Black List. There is no other evidence provided that this is only what it does, nor does it mean that Apple can't use it in some other form or that they're not working on a set of black listed applications they can retrospectively turn off. Apple have already shown how developer friendly they are by pulling applications from their store without warning.
Personally, I find a black list like this an exceptionally stupid and blunt way to deal with access to Core Location.
I might not have one of the lowest Slashdot IDs around, but I am absolutely astonished at some peoples' astonishment over this. DNS, by definition, is all about trusting the forwarders you are using or other DNS servers you are caching from and trusting the DNS server you use from there. That's where the problem is, so if people are shouting and screaming about trust now then it's all a bit late.
If your DNS server says that slashdot.org resolves to something other than 216.34.181.45 then that's where you're going to end up. There are also legitimate reasons why someone might want to do something like that, and it is part of the inherent flexibility that has made the internet and its technologies as ubiquitous and as well used as they are. No one said that there weren't downsides. If you locked everything down in the manner that some idiots will inevitably now talk about, shouting and squealing about financial institutions, then I'm willing yo bet that you will lose a good portion of the flexibility that makes the 'internet' actually work on a wide scale.
Is this just a mark of the current climate, or is this a general trend that's been going on for a few years now?
For industry specific and niche applications it is doubtful whether you will ever get a set of open source applications for a lot of set purposes. What is required are reasonably straightforward development frameworks for application developers to pick up, create a wide variety of software and be able distribute those applications easily to you. Linux and open source software has various parts of this in place, but the main problems aren't being solved. If we get that then maybe open source developers from the Windows world will chime in as well and create a snowball effect.
It has one. It's called Qt (yes, it works everywhere well on Linux, Unix, OS X and Windows), it really works and it even has a modern desktop environment developed with it called KDE with frameworks being developed that are trying to solve some of the more pressing problems we've had for years - easy desktop scripting and development, easy installation, integration of the OS with the desktop etc.
Unfortunately, the vast majority of the Linux companies seem to be fannying about with stuff that isn't going to work or move forwards this side of the next ice age.
Rather than moaning about the fact that other people aren't putting in the effort into pushing development frameworks forward to allow developers to create lots of great applications, and helping them distribute said applications to users, maybe IBM should, you know, put in a tiny percentage of its overall costs and resources and bloody well do it?
Even more ironic is the fact that Bob Sutor (I believe) is one of the open sorce people at IBM who has pontificated about the evils of OOXML and the promotion of ODF. Well Bob, applications rule and if you want to help out, rather than lobbying the mess that is the ISO process and moaning in blogs, get out there and help produce some kick-ass ODF-using applications that people feel that they just have to use above Microsoft Office. No, creating yet another version of Open Office, but proprietary, and calling it Symphony, is not the answer. Meanwhile, as the main problems don't get solved, he then talks bullshit about cloud computing, that huge bullshit about how operating systems are less visible and matter less and software as a service.
The open source world is full of armchair moaners willing to pontificate about the deficiencies of Linux and open source software as a platform. Worryingly, these are sometimes quite large companies who profess to use Linux and open source software as a main source of income. They might moan about the current situation, but IBM's past history with OS/2 and Windows shows that they still have no clue whatsoever what needs solving.
I take it he's also going to kick Bishop Brennan up the arse as well for good measure?