We previously saw a Fox News pie chart that had a couple extra slices (here). Now, fair and balanced math adds up to 120 percent of voters indicating that they view the science on global warming to be rigged.
This is an interesting Rasmussen poll when you add up the number and discover that you are in a parallel universe.
The question is: “In order to support their own theories and beliefs about global warming, how likely is it that some scientists have falsified research data?” According to the poll, 35 percent thought it very likely, 24 percent somewhat likely, 21 percent not very likely, and 5 percent not likely at all (15 percent weren’t sure).
This rather dubious poll is offered to show that people are dubious about the science and math of global warming experts.
For the full story, click here
Okay Byron,
Clarify it for me.
How many joules does it take to ‘liquify’ one kg of steel? And at what velocity must one kg of steel need to fall in order for it to ‘liquify?’
That’s the gist of Slarti’s argument.
Perhaps you can better explain this phenomena.
Bob posted:
“Slartibartfast: “Initially, this box contains approximately one trillion joules of gravitational potential energy. All of this energy either remains in the box or is transferred out of the box”
All or nothing?? Whatever, since you’re allowing for energy & work to permeate the barrier of your system, your talking about a closed system rather than an isolated system.”
I’m sorry, I thought that you would understand that each bit of energy would be required to either stay in the box or exit the box. The important thing is that we keep track of it, as it is neither created nor destroyed.
Just to be sure, I called a fellow engineer. He’s the senior engineer at a firm that specializes in product failure testing. He agrees that when analyzing the WTC you cannot consider it to be anything but an open system. That which you cannot account for is lost. I also pointed out how Slarti came up with his 17.4%. He laughed.
He did point out that in building construction floors are considered to support static weight, and that a floor is designed to withstand 5 times the designated load.
If I take the floor weight and then double the design load (rather than multiply by 5) to be conservative, I should be able to represent the amount of force needed to break the floor free.
Bob posted:
“Slartibartfast: “I have said repeatedly that 17.4% of the gravitation potential energy of the WTC went into breaking the structure of the building and pulverizing the rubble.”
Slartibartfast: (from an earlier post) “I calculated that 17.4% of the original gravitational potential energy went into collapsing and pulverizing the building.”
How? By working backwards in a post hoc ergo propter hoc fashion?”
More carefully I should have said that assuming a ‘natural’ collapse with the times given 17.4% of the GPE was available for collapsing and pulverizing the structure of the building and generating the pyroclastic flow and 82.6% was tied up in kinetic energy. This calculation is factual and relevant to the question of explosives being necessary to assist the collapse.
Slarti:
how are you accounting for the energy required to separate the floors from the main structural members?
A 3/4″ diameter A36 steel rod/bolt fails at a force of around 43,000 lbs give or take.
I am guessing the concrete was only 3″ possibly 4″ thick.
There is so much going on when a building collapses like that. I think it would be near impossible to model exactly what is happening. Your model is probably as good as anything in that you are just looking at GPE and KE.
I don’t agree with Bob and Robert and I agree with you but this exercise has shown how complicated this actually is, and I think that is part of the problem. The simple answer is Controlled Demolition. And so I think people that think it was planes are at a bit of a disadvantage unless they have a PhD in math or science.
Robert said:
“Did the WTC interact with the environment during collapse? YES
Did the WTC transfer energy to the environment during collapse? YES”
So you think the sonic energy was important. Was it as loud as a rocket up close and personal? Was it as loud as the Krakatoa eruption from 100 miles away? Did it last for 50 seconds? If so, congratulations, you’ve just bought yourself 50 megajoules. You’re 0.01% of the way there – only 499,950 megajoules to go…
Robert said:
“Did the WTC transfer mass to the environment during collapse? YES”
I neglected this and I mentioned it as well. It’s reasonable to assume that apart from the pyroclastic flow (which I’ve repeatedly mentioned) most of the debris came down within 300 meters or so of the towers. My assumptions are reasonable and I’ve specified them clearly.
Robert said:
“The only thing that makes the WTC collapse take place in an isolated system is your claim that it did. It’s hogwash.
You would claim that everything in the world exists in an isolated system. That’s bullcrap.”
I’ve defined my system as the entire universe. Are you saying that the WTC collapse did not occur in the universe or that the universe is not a closed system?
Robert said:
“The majority of energy that interacted with the ground was transferred to the earth. The material that landed on the ground in the beginning was struck by the material that landed later. They transferred their energy to the earth. It caused a minute ripple in the sea. That’s what happens when energy is dissipated.”
Energy was transferred into the ground, this is seismic energy and is possibly the most accurately specified quantity in the collapse. A seismic event of magnitude 2.1 requires 5.9 gigajoules of energy – that’s better out of 500 gigajoules, unfortunately I’ve already accounted for it. The first ‘layer’ of rubble transferred energy to the earth (as heat), subsequent ‘layers’ transferred energy at heat to the layer beneath them.
I found a real world application for Slarti’s math.
[youtube=http://www.youtube.com/watch?v=nQsObzDsYd8&hl=en_US&fs=1&]
Slartibartfast: Bob, Go back to school.
You said:
“You’re now forced to account for the Work creating heat”
I’m not in violation of the law of conservation of energy, you are. You don’t ‘create heat’ by ‘doing work’, you obtain heat by converting it from other forms (e.g. when you lie in the sun electromagnetic energy is converted into thermal energy – there’s also quite a bit of DNA damage, so wear sunscreen).”
Actually, I was replying to a comment by Robert, to wit:
Robert: “The pulverizing of cement into rubble expends a lot of energy in the form of work. The ejection of metal girders 600 ft expends a lot of energy in the form of work.”
My comment: “No argument here. And once the Pe is used to do work, it can’t be used again to create pure Ke and then heat. You’re now forced to account for the Work creating heat; which is another reason his meteor analogy falls short.”
This comment is based on the premise that far more than 17% of the PE would be required to be converted into work to shred the building; seeing the mere design and construction of said building would require far more commanding opposing forces (Newtons) to keep it standing in the first place.
Per your comment “You don’t ‘create heat’ by ‘doing work’,”
Let’s review: work = the force of one newton acting over a distance of one meter; i.e. one Newton meter. And since we’re dealing with metal against metal, what’s that other implicit element in the equation called?
Friction?
That doesn’t create heat; it just pisses people off man.
Bob said to Slarti “All or nothing?? Whatever, since you’re allowing for energy & work to permeate the barrier of your system, your talking about a closed system rather than an isolated system.”
Bob, You don’t understand. Slarti’s system is the universe. Energy and mass can do whatever it needs to, and mass can go wherever it wants.
Tomorrow I can open the coolant relief for testing and be comfortable in knowing that it should have remained in a closed system, but a mathematical biologist told me how to make it an isolated system. Now we don’t need to worry about the environment. We just expand it to the universe.
I wish Slarti would have gone to Copenhagen. No need to worry about global warming, we have a whole universe to maintain.
Slartibartfast,
How could you tell the difference between a building that was taken down by controlled demolition and one that was the result of structural failure? What part of your math would indicate the difference?
Slartibartfast: “I have said repeatedly that 17.4% of the gravitation potential energy of the WTC went into breaking the structure of the building and pulverizing the rubble.”
Slartibartfast: (from an earlier post) “I calculated that 17.4% of the original gravitational potential energy went into collapsing and pulverizing the building.”
How? By working backwards in a post hoc ergo propter hoc fashion?
Slartibartfast: “Some of this energy left the system via particles in the pyroclastic flow. The rest of it remained in the debris as heat (I didn’t include this energy in my analysis – effectively assuming that all of this energy left in the pyroclastic flow). Consider an imaginary box that completely contains the WTC (from the subbasement to the tip of the radio masts).”
Would this be a closed system or an isolated system?
Slartibartfast: “Initially, this box contains approximately one trillion joules of gravitational potential energy. All of this energy either remains in the box or is transferred out of the box”
All or nothing?? Whatever, since you’re allowing for energy & work to permeate the barrier of your system, your talking about a closed system rather than an isolated system.
Slartibartfast: “I have kept track of the energy that stayed in the box and estimated that enough of it was converted into heat to liquify approximately 1,000 metric tons of iron at room temperature. I have not in any way violated the law of conservation of energy.”
And here we are again with you invoking the fallacy of post hoc ergo propter hoc and further begging the question of that which you’re allegedly setting out to prove. From what you’ve said, you’re getting your 17.4% by assuming the collapse liquified “approximately 1,000 metric tons of iron at room temperature.” I ask you to show me the mechanism by which the steel was liquified, or how the Pe was converted to Ke and thence heat, and you give me hypotheticals about meteors and speeding bullets –attempting to build an analogy that is ultimately false. False because you ignore the work involved in creating the rubble and false because you ignore the ‘want of velocity’ far in excess of the highest terminal velocity allowed on planet Earth.
Slartibartfast: “Since energy is neither created or destroyed, a good portion of this energy ends up where most (all?) energy ultimately ends up (in accordance with the 2nd law of thermodynamics) as randomized motion of particles – i.e. heat.”
Not all randomized particles generate heat. Dust clouds don’t necessitate heat; shattered glass doesn’t necessitate heat. Who are you kidding?
Slartibartfast: “However, I have repeatedly said that I DID NOT INCLUDE THIS ENERGY IN MY CALCULATION OF THE HEAT GENERATED! In other words, you have no legitimate complaint here, since even if your argument was correct (which it is not since it violates conservation of energy, which is a pretty serious flaw in a physics argument), it’s still irrelevant since I excluded this energy from my heat calculation.”
Yet your ‘heat calculation’ begs the question that falling steel from a collapsing building generates enough heat energy to create a furnace to melt the steel; for reasons that have something to do with speeding meteors and bullets… somehow.
Slartibartfast:
Bob said:
“Energy, by definition, is the capacity of an object for doing work; normally measured in joules.
A joule is the amount of work done by a force of one newton moving an object through a distance of one meter.
1 Newton = 1 kg m/s^2
1 Joule = 1 kg m/s^2 x 1m or 1 kg m^2/s^2
If the majority of the potential energy of an object (Oh, say the WTC Towers) is used in the creation of Work, (Force and movement in the direction of said force), i.e. that which is (allegedly) shredding the building, it cannot ALSO be counted as pure kinetic energy. Assuming a pure unassisted collapse, whatever PE wasn’t converted into work to break apart the Towers exists as a small remainder of Ke following the path of work on the way down.”
By what argument do you claim that the ‘majority’ of the potential energy went into shredding the building?”
Me talking now:
Gee, you don’t suppose that the building was designed to provide more than sufficient opposing forces (Newtons) to keep all that
potential energy from converting to Ke and just falling down; do you? You don’t suppose that those opposing supporting forces, expressed in the design of the buildings, were meant to be far greater than those resulting in the height and mass of the completed structure? Seriously??
Slartibartfast: “There was clearly an enormous amount of kinetic energy present in the rubble before it slammed into the ground (in many inelastic collisions).”
Did you check the seismogram?
Slartibartfast: “By estimating the speed of collapse vs. free fall, I was able to calculate that 82.6% of the gravitational potential energy was present in the form of kinetic energy, leaving 17.4% of the gravitational potential energy (100,000,000,000 joules) for destroying the structure of the building. These percentages change if you change the collapse time vs. free fall time, but the calculation is correct.”
So 17.4% of the total GPE, i.e. that representing the existence (mass, height (& g)) of the entire building, was capable of shredding said entire building? That’s all the Work that was required to create the pile of rubble? Tell me, other than wishful thinking, what forces were holding up the building for the thirty years of its existence and where did they go on 9/11? And given this oddly excessive amount of free Ke, why don’t your calculations support the theory of controlled demolition? If demolition devices weren’t removing the supports (i.e. forces opposing collapse) of the building, then how did it fall at near free fall speed?
Slartibartfast: “In science, we don’t get to say things that we can’t back up with evidence of one sort or another (well, we can say things, but no one gives them credibility). It is indisputable that there was something like 1,000,000,000,000 joules of GPE stored in the towers. It is indisputable that the falling debris contained kinetic energy. It is indisputable that the rubble pile did not contain this kinetic energy. It is indisputable that this energy was not destroyed.”
It’s that last part where you confuse your thought experiment and the actual expenditure of energy during the event.
Slartibartfast: “You don’t have to take my word for any of these things, this is what physics says – contradict them and you loose all scientific credibility. I have done a calculation (which I clearly laid out) to estimate what portion of the GPE went into KE in the descending rubble pile”
Yes, the ‘descending pile of rubble’ — existing in free fall before it’s even created by the destruction of the building below. Uh huh.
Slartibartfast: Are you saying that tons of explosives were covertly placed in the towers?) Show me the calculation that justifies that the majority of potential energy went into destroying the building.”
How many joules does it take to ‘liquify’ one kg of steel? And at what velocity must one kg of steel need to fall in order for it to ‘liquify?’
Seriously; tell me.
Slartibartfast:
Bob said:
“Finally Robert, there is no ‘impact’ event; the analogy is false. A building existing on earth and collapsing on earth is not said to ‘impact’ the earth — because you can’t GET THERE from here. And with the building being on earth, you sure as shit can’t raise the velocity component of Ke, for any debris not involved in the work of tearing the building apart, any higher than terminal velocity will allow–thus making the meteor analogy completely inapplicable.”
I’m assuming you meant Slart, not Robert.”
No, I was talking to Robert.
Slartibartfast: “Terminal velocity is when the force of atmospheric drag (friction) is balances the force of gravity and a falling body stops accelerating. It is not in play in ANY of the situations we’ve been discussing.”
Actually, terminal velocity is reserved for the phenomena of free fall; you’re not even discussing the opposing forces involved in the net work product required to shred the building. Tends to slow things down and use up more energy.
Once again: How many joules does it take to ‘liquify’ one kg of steel? And at what velocity must one kg of steel need to fall in order for it to ‘liquify?’
I have an admission to make – I made an error in my calculation. Instead of enough heat generated in the collapse to liquify just over 500 metric tons of iron at room temperature, there is only enough to liquify just over 300 metric tons of iron at room temperature.
You might ask why I posted this. I didn’t have to – no one would have found my mistake (unless someone tried to reproduce my results). But I would have known that the mistake was out there uncorrected, so I fixed it. At one point in the calculation I made an error and got a very disappointing result. As you can expect, I was disappointed – not because I then couldn’t use the calculation, but because I would have to post it and admit Bob was right (that would have stung). This is the appropriate ethical standard for scientists. While not all live up to this, most of us do.
The numbers above are incorrect in any case, since I took the collapse vs. free-fall times from WTC7 instead of WTC1 or WTC2. Since I don’t really expect Robert to be able to do this, I’ll work the numbers again (with the correct times) and let everybody know what I find.
Slartibartfast,
Did the WTC interact with the environment during collapse? YES
Did the WTC transfer energy to the environment during collapse? YES
Did the WTC transfer mass to the environment during collapse? YES
The only thing that makes the WTC collapse take place in an isolated system is your claim that it did. It’s hogwash.
You would claim that everything in the world exists in an isolated system. That’s bullcrap.
The majority of energy that interacted with the ground was transferred to the earth. The material that landed on the ground in the beginning was struck by the material that landed later. They transferred their energy to the earth. It caused a minute ripple in the sea. That’s what happens when energy is dissipated.
Byron,
I’m just making simplifications for different goals – and taking the system to be the universe is about as simple as you can get! Don’t worry, I wont make you account for every sirocco in Cairo or every supernova in Alpha Centauri, just the GPE of the WTC. You know what comes next, don’t you?
Byron,
I am intimately familiar with the Charpy V-notch test. Brittle fracture (or the prevention thereof) is very important to the design and operation of a nuclear power plant.
Slarti:
we engineers look at things in terms of free body diagrams. The WTC site would be isolated from the rest of the world to determine energy state changes, etc. We try to overly simplify things so we can solve them. 🙂
Byron said:
“I think that once the buildings came down it was a partially isolated system as you had 5 sides of solid concrete around and below the debris. As you all know your basement has a fairly constant temperature. So I think Slarti’s contention of a closed system is not that far out of line. It certainly wasn’t a 100% open system because of the constraints given by the foundation and surrounding soil.”
I think you guys are getting too hung up on the closed system thing. Try this:
1) Take the universe as your closed system.
2) This system includes 1 trillion joules of GPE stored in the WTC.
3) Since energy is conserved, this energy remains in the system for all time.
4) Account for that energy.
This is exactly what I did.
Byron,
An open system can exchange mass and energy with the environment. This meets the very definition of an open system.
BTW: Someone was asking “how much sulfur”. U.S.G.S analysis is available here. http://pubs.usgs.gov/of/2001/ofr-01-0429/
Sulfur% MIN 0.87 MAX 5.77 AVG 3.11
Robert said:
“Each floor required 14 billion joules of energy to break it loose.”
Slartibartfast said “Show your work.”
Why? Your the one claiming that the building had enough GPE to break loose the floors and pulverize the concrete, and sustain near free fall speed. You allotted roughly 17,400,000,000 joules to break loose the floors and pulverize the concrete. That’s 160 million joules per floor. There were approximate 2500 ruptures/cuts (whatever you want to call them) leaving about 64,000 joules to cut each section of steel beam. Witnesses noted that the beams were cut on 45 degree angles (hmmm?). A diagonal cut would require more energy. The average steel beam is 2″ thick, and 24″ x 10″.
Bob said:
“Even more troublesome is begging the question that buildings are capable of collapsing at near free-fall speed without any ‘help.'”
I did a calculation showing the distribution of energy involved in the collapse so we could have a scientific discussion about the collapse being natural vs. explosive assisted. You’ve provided zero evidence that explosives could compare to the energy naturally present. The speed of collapse tells us how the ‘natural’ energy is distributed between kinetic and building-shredding energy – if the building-shredding energy is not sufficient, please give evidence that it is not along with an estimated amount of explosives that would be required to add to it. With numbers.