Here's a question: How much energy doesn't it require to pulverize concrete?
E = MGH
Undeniably.
converting steel reinforced concrete to powder and ejecting tons of steel hundreds of feet in some cases uses a great deal of that potential energy.
This is all correct so far.
Have you plugged in numbers for M, G and H in the formula above? What was the result for E?
[1]
Your question seems to doubt that the potential energy E
pot was insufficient to crush all the concrete and fling all the debris the way you observed it. In formal terms, you'd claim:
Epot < Ecrush + Efling
But is this inequality true? The only way to figure out if this inequality really holds true is if you can provide a
numerical upper limit for E
pot and a
numerical lower limit for E
crush + E
fling - you actually need the
numbers.
So what are your numbers? If you don't have any, you are indeed clueless here and can't know if the potential energy was sufficient or not.
However, if you like to claim,
in the absence of well-calculated numbers, that E
pot is insufficient, that would imply that you need to add an extra amount of energy E
extra in the form of ... whatever floats your boat: Explosives, nanothermite, high-ebergy beams, and that E
extra would have to be a major fraction of E
pot, or perhaps even be larger than E
pot. If your argument rests on intuition, I say that your E
extra would have to be at least 50% of E
pot.
That would be equivalent to >60 tons of TNT in each tower, or more than a thousand pounds of TNT for each of the 220 floors of the twins.
Here is a video of the explosive demolition of the 30-floor Landmark Tower in Fort Worth, Texas:
http://www.youtube.com/watch?v=vzZBXuyIE28
And here is an article on how it was done:
http://www.dhgt.com/PDF/A talented team of demolition experts.pdf
From this you learn that only 364 pounds of explosives were needed to bring down the Landmark - and how many extremely loud explosions these 364 pounds generate.
I have estimated that the energy of these explosives at the Landmark was around 1 Gigajoules, and the potential energy of that Tower was around 8 Gigajoules - and really, that potential energy, or gravity, accounts for over 85% of the physical damage incurred during the demolition.
Anyone who wants to argue that there wasn't nearly enough potential energy to account for the pulverisation and other things at the WTC and that the balance was provided by
explosives, would have to explain why the > 1,000 pounds (average) of explosives in every floor weren't as loud as, or louder than, what you hear in the Landmark. You'd need ti explain why the impressive sounds weren't heard 220 times as prominently as in Fort Worth.
Anyone who wants to argue that the energy balance was provided by nefarious means other than explosives would have to offer a theory on what sort of energy source that woud be that crushed concrete and flings large sections of steel.
In the meantime, every sane engineer on the planet understands that the potential energy of the towers really was enough.
I could search for a link to a paper by Frank Greening who calculated the numbers I asked you for years ago: He calculated the potential energy (that's fairly easy), and also calculated the energy needed to crush concrete as observed. And found that both numbers are in the same ballpark. Which means, that potential energy sufficers, or conversely, that the amount of destruction is consistent with what one would expect from gravity alone.
But those calculations would be way over your head.
ETA: By coincidence, I stumbled across a link to the Greening-paper elsewhere: http://www.911myths.com/WTCREPORT.pdf
Appendix 2 contains the calculations for concrete crumbling.
"Where is the delay that must be expected due to conservation of momentum – one of the foundational Laws of Physics? That is, as upper-falling floors strike lower floors – and intact steel support columns – the fall must be significantly impeded by the impacted mass.
All three falls are in fact impeded and accelerate, on average, at only 50-65% of freefall acceleration. Parts of the buildings of course may fall at freefall accelerations, others may decelerate for periods of time. There are leverage effects that allow both deviations from the averages.
If the central support columns remained standing, then the effective resistive mass would be less, but this is not the case – somehow the enormous support columns failed/disintegrated along with the falling floor pans."
That is poorly observed.
During the collapse progression phase of the twin towers, there is hardly any observation of the behaviour of the core possible, so we can't know if they "failed/disintegrated
along with the falling floor pans", or
ahead of them, or
trailing them. However, late in the collapses, it can be observerd that significant portions of the cores, reaching many dozends of floors, are still standing while all the floor pans have already reached the ground, so this proves that the floor pans failed/disintegrated
ahead of sognificant portions of the cores at least in the latter stages of collapse progression.
Is that just a bunch of truther nonsense?
Yes.
"Both WTC 1 and WTC 2 were stable after the aircraft impact, standing for 102 min and 56 min, respectively. The global analyses with structural impact damage showed that both towers had considerable reserve capacity. This was confirmed by analysis of the post-impact vibration of WTC 2… where the damaged tower oscillated at a period nearly equal to the first mode period calculated for the undamaged structure. (NIST, 2005, p. 144; emphasis added.)"
Was NIST lying? Or is that misleading information?
No, that is accurate information. This is talking about the effect of the plane crashes (kinetic energy) of the planes
alone, before entering the very large and desastrous fires that are a well-known hazard to any steel construction.
Footnote:
[1] Here is my result:
http://oystein-issues.blogspot.de/2010/09/potential-energy-of-mass-of-each-twin.html
E
pot = 4.8 * 10
11J - that's equivalent to close to 120 tons of TNT
This is really some kind of performance art, isn't it? You're really Sacha Baron Cohen, aren't you?
