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Inside Job—9/11 Truth and other 9/11 Discussion (Merged)
Posted: 15 September 2008 06:09 PM   [ Ignore ]   [ # 271 ]
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The popular mechanics link should be the last word on this,  but (*deep sigh*), it won’t!

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Posted: 15 September 2008 08:43 PM   [ Ignore ]   [ # 272 ]
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asanta - 15 September 2008 06:09 PM

The popular mechanics link should be the last word on this,  but (*deep sigh*), it won’t!

ROFLMAO

Shouldn’t the Bible be the last be the last word on Christianity?

LOL

But if you check the word HELL isn’t even in the Bible.  SHEOL is translated as HELL in the Old Testament but the translation is wrong.  How many so called Christians don’t know that?

People that BELIEVE don’t check.  You hadn’t noticed that dictionaries put Europe first in the list of continents even though it shouldn’t be first in an alphabetical list and dictionaries tend to be alphabetical.  Curious contradiction that!

Popular Mechanics brings up that business about pockets of fire at 1800 degrees but I challenge you to find information about that in the real NCSTAR report, NOT THE SUMMARIES.

And atheists are supposed to be so intelligent, rational, scientific and skeptical.  LOL

Apparently it is easy for some people to BELIEVE that a 175 ton airliner can cause the vertical collapse of a 400,000+ ton building in less than 18 seconds and yet not even ask about the distribution of mass in relation to the conservation of momentum.  Yeah, very scientific!  ROFL

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Posted: 15 September 2008 08:49 PM   [ Ignore ]   [ # 273 ]
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Jaik - 15 September 2008 04:27 PM

When you cited your video and then mentioned how it’s “Popular Mechanics” something in my head rang a bell.

This was it: http://www.democracynow.org/2006/9/11/exclusive_9_11_debate_loose_change

Popular Mechanics editors debunk this stuff all the time.

I don’t pay any attention to Loose Change.  Some people pick weak targets to debunk so it is easy for them to win, or at least claim to win, their debates.

I suggest 9/11 Mysteries.

http://video.google.com/videoplay?docid=-3944047011450313064&ei=EizPSJebMI3I-gHNpuDBAg

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Posted: 15 September 2008 10:10 PM   [ Ignore ]   [ # 274 ]
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psikeyhackr - 15 September 2008 08:43 PM

Apparently it is easy for some people to BELIEVE that a 175 ton airliner can cause the vertical collapse of a 400,000+ ton building in less than 18 seconds and yet not even ask about the distribution of mass in relation to the conservation of momentum.

This may have been answered pages ago, but I would like a clarification.  What else would you suggest caused it?

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Posted: 15 September 2008 10:12 PM   [ Ignore ]   [ # 275 ]
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There is such a thing as reasonable doubt. Your doubt has passed into obsessively irrational a long time ago.

There is NO evidence that will ever budge you from your point of view—-even if a ‘god’ spoke to the world from a cloud for all to hear. You are no different from the christians and muslims in their aguments about the existence and pronouncements of ‘their’ god. They will never doubt ‘god’s’ existence, and you will never believe there is no conspiracy.

It does absolutely NO good to present you with facts, I fail to understand why this irrational thread had gone on for soooo long.

If everyone else is wrong but you, it’s time to get out the mirror and look at yourself—-with your eyes and mind open.

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Posted: 11 October 2008 09:25 AM   [ Ignore ]   [ # 276 ]
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I am not talking about WHAT DID DO IT, I am saying the physics dictates that the planes could not do it.  So why don’t we have a table specifying the TONS of STEEL and TONS of CONCRETE on every level after SEVEN YEARS?

I thought atheists claiming to be SCIENTIFIC should be able to handle the math for Newtonian physics.  I haven’t responded since the last two posts didn’t explain or refute anything but now it is time to BUMP.

Fall of Physics

In my rarely humble opinion (LOL) many of the people who claim the WTC towers underwent gravitational collapse seem to exaggerate what gravity can do. This is a table showing the velocity and distance fallen by an object from a stationary start. In the first 1/10th of a second the mass moves less than 2 inches and is only traveling at 3.2 ft/sec. So a gravitational collapse of the WTC meant the falling top portion must have accelerated what it struck much more than gravity could have and also have broken whatever was supporting that intact portion of the building.

.           == initial velocity
    Time    V 
at v     D 1/2 at^vt
               v 
0
    00.1     3.2 ft
/sec    0.16 ft   1.92 in.
    
00.2     6.4 ft/sec    0.64 ft   7.68 in.
    
00.3     9.6 ft/sec    1.44 ft  17.28 1n.
    
00.4    12.8 ft/sec    2.56 ft
    00.5    16.0 ft
/sec    4.00 ft
    00.6    19.2 ft
/sec    5.76 ft
    00.7    22.4 ft
/sec    7.84 ft
    00.8    25.6 ft
/sec   10.24 ft
    00.9    28.8 ft
/sec   12.96 ft
    01.0    32.0 ft
/sec   16.00 ft
    01.1    35.2 ft
/sec   19.36 ft
    01.2    38.4 ft
/sec   23.04 ft
    01.3    41.6 ft
/sec   27.04 ft
    01.4    44.8 ft
/sec   31.36 ft
    01.5    48.0 ft
/sec   36.00 ft
    01.6    51.2 ft
/sec   40.96 ft
    01.7    54.4 ft
/sec   46.24 ft
    01.8    57.6 ft
/sec   51.84 ft
    01.9    60.8 ft
/sec   57.76 ft
    02.0    64.0 ft
/sec   64.00 ft 

No matter what brought the towers down the conservation of momentum cannot have been violated. This is the equation for an inelastic collision in which two masses stick together. If the second mass is stationary then v2 is zero.

Conservation of Momentum:

(m1 * v1) + (m2 * v2) = (m1 + m2) * v3

This means the ratio of the stationary mass to the impact mass greatly affects the resulting velocity. If the impact mass is smaller then it will be slowed considerably, but in the opposite case the velocity of the stationary mass will change a lot. But in a gravitational collapse there will be the additional effect of gravitational acceleration before and after impact.

So I have done the calculations for 3 “magical” cases. In each case four masses are magically suspended and when struck from above each mass is released with no resistance. In case #1 the 4 masses are are equal, 2.5 tons each. In case #2 the masses are in the sequence 1, 2, 3 and 4 tons from top to bottom. Case #3 is the reverse sequence of 4, 3, 2 and 1 ton. When the masses are struck from above they begin moving on the basis of conservation of momentum and undergo gravitational acceleration until the next object is struck. Case #0 is just a 10 ton mass dropped from 64 feet with no impacts and is used as a reference case.

.            mass 1     mass 2      mass 3        mass 4
             64 feet   feet 48      feet 32      feet 16
                 
    
Case 0    10 ton      0            0            0
    speed       0        32          45.25        55.43         64 ft
/sec     
    time        0         1           1.41         1.73         2 sec

    
Case 1    2.5 ton    2.5          2.5          2.5
    speed       0       32 16     35.78 23.85  39.91 29.93      43.82 ft
/sec
    time        0         1       1.618 14
%     2.12 23%       2.554 sec 28%

    Case 
2    1 ton       2            3            4
    speed       0       32 10.67  33.74 16.87  36.17 21.70      38.66 ft
/sec
    time        0         1       1.721 22
%    2.324 34%       2.854 sec 43%

    Case 
3    4 ton       3            2            1
    speed       0       32 18.29  37.35 29.05  43.23 38.91      50.37 ft
/sec
    time        0         1        1.58 12
%    2.023 17%       2.381 sec 19

 

The Case line specifies the weight of mass at each of the 4 heights, 64, 48, 32 and 16 feet. These heights were chosen because they correspond to the “1/2 * 32 feet/sec^2” that is in the distance from acceleration equation thereby making calculations easier.

The speed line has the velocity of the net mass before and after impact based on conservation of momentum.

The time line has the time for the mass to fall to that point and the percentage difference from Case 0.

A body in freefall dropped from the top of the World Trade Center would have taken 9.2 seconds to reach the ground. The NIST says the tower that took longer to collapse did it in 11 seconds. So that is only 20% longer than the freefall time. But the WTC collapses required that the tens of thousands of tons of steel and concrete which had held up the buildings for 28 years be bent and broken and crushed. So how is it that only my absurd and miraculous collapse with inverted masses and disappearing supports comes down that fast in relation to freefall? A skyscraper must be bottom heavy and Case #2 using that distribution has double that percentage of time but it didn’t require kinetic energy be used to break supports.

So what is the story with all of these people that claim there was a gravitational collapse but also pretend that knowing the TONS of STEEL and TONS of CONCRETE on every level isn’t necessary? I have demonstrated that changing the distribution of mass alters the collapse time regardless of the strength of the material involved and how much kinetic energy would be required to break it.

Time and velocity calculations after impacts:

.   After Impact #1: 
    
Case 116 16t^16t     1 t^t          t 0.618  19.78+16
    
Case 216 16t^10.67t  1 t^0.666875t  t 0.721  23.07+10.67
    
Case 316 16t^18.29t  1 t^1.143125t  t 0.58   18.56+18.79

    After Impact 
#2:
    
Case 116 16t^23.85t  1 t^1.490625t  t 0.502  16.06+23.85
    
Case 216 16t^16.87t  1 t^1.054375t  t 0.603  19.30+16.87
    
Case 316 16t^29.05t  1 t^1.815625t  t 0.443  14.18+29.05

    After Impact 
#3:
    
Case 116 16t^29.93t  1 t^1.870781t  t 0.434  13.89+29.93
    
Case 216 16t^21.70t  1 t^1.35625t   t 0.53   16.96+21.70
    
Case 316 16t^38.91t  1 t^2.431875t  t 0.358  11.46+38.91 

http://www.richarddawkins.net/forum/viewtopic.php?p=1058903#p1058903

No one on richarddawkins.net found any flaws in the math in 3 months, not even the man claiming to be a structural engineer.  He just complained about left brained physics.  LOL

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Posted: 11 October 2008 09:51 AM   [ Ignore ]   [ # 277 ]
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I think that the fundamental flaw in your calculation is that it has built into it the assumption that the collapse started at the top of the building and worked its way downward. This is not what happened. The aircraft struck the building at about 2/3 of the way up from the ground. Thus, when the structural steel at that point softened, the entire upper third of the building began to fall. This upper third of the building was much heavier than each of the floors it struck in sequence, so there was no significant reduction in velocity due to the increase in mass of the falling material. Thus, your calculation does not represent the physics of the collapse and yields incorrect results.

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Posted: 12 October 2008 05:41 PM   [ Ignore ]   [ # 278 ]
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Chris Crawford - 11 October 2008 09:51 AM

I think that the fundamental flaw in your calculation is that it has built into it the assumption that the collapse started at the top of the building and worked its way downward. This is not what happened. The aircraft struck the building at about 2/3 of the way up from the ground.

There were two planes that hit two buildings, the north tower at the 94th floor and the south tower at the 81st.

81/110 = 74%    94/110 = 85%

It was not 67%.

Using 4 masses I am having the top 25% fall on the rest if the masses are equal.  However the density of a skyscraper must increase toward the bottom so mass to volume ratio must change. 

The next problem is distribution of mass.  Skyscrapers must be bottom heavy so the percentages of the buildings by volume above the impact points must weigh less than the same percentage below the impact points.

Thus, when the structural steel at that point softened, the entire upper third of the building began to fall. This upper third of the building was much heavier than each of the floors it struck in sequence, so there was no significant reduction in velocity due to the increase in mass of the falling material. Thus, your calculation does not represent the physics of the collapse and yields incorrect results.

My calculations do not represent the WTC because they are based on MASS ONLY.  My calculations TOTALLY IGNORE RESISTANCE resulting from the strength of the material that had to be destroyed.

If a mass impacts a stationary mass of the same size the velocity will be cut in half.  Since the kinetic energy equation squares the velocity doubling the mass and halving the velocity results in 50% of the kinetic energy in the collective mass.

If a mass hits 10 stationary masses each 10% of the original mass each will change the kinetic energy after impact.  The sequence of changes would be:

0.9091 * 0.9167 * 0.9231 * 0.9286 * 0.9333 *

0.9375 * 0.9412 * 0.9444 * 0.9474 * 0.95

Multiplying all of those numbers yields 0.500038846

So the net result of hitting the levels in sequence would be the same net energy as hitting a number of them simultaneously.  But that still does not take into the account the energy losses necessary to bend steel and crush concrete at each level.

So my point is to demonstrate that this analysis cannot be done anywhere near accurately without knowing the TONS of STEEL and TONS of CONCRETE on every level which we still do not have after SEVEN YEARS.  So believing the towers could collapse in less than 18 seconds without that information is absurd.

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Posted: 12 October 2008 06:22 PM   [ Ignore ]   [ # 279 ]
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I stand corrected on the height at which the planes hit the building. That point, however, does not alter the basic reasoning used here.

Your calculation also errs in treating the material as having a fixed velocity. The velocity of all the material is increasing as it falls.

Lastly, your biggest problem is that you have no alternative hypothesis. If the buildings didn’t fall down, what brought them down? A giant vacuum machine in the basement? A monster foot from heaven that smashed them down (and somehow went unnoticed by thousands of observers)?

A good calculation of the collapse is rather messy, which is why I’m not doing it for you, but there’s nothing at all strange about the fact that the towers accelerated downward at just short of g. It’s pretty much what you’d expect.

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Posted: 12 October 2008 07:24 PM   [ Ignore ]   [ # 280 ]
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Chris Crawford - 12 October 2008 06:22 PM

Your calculation also errs in treating the material as having a fixed velocity. The velocity of all the material is increasing as it falls.

That statement proves you either did not read or did not understand FALL OF PHYSICS.  The lines that say “SPEED” in the second CODE box specify the speed of the falling mass before and after each impact and you can see that the speed before each impact is greater than the speed after the last impact.  That is due to gravitational acceleration.

The Speed line for case #2 is:

speed   0=>32#10.67=>33.74#16.87=>36.17#21.70=>38.66 ft/sec

I put a # sign where the velocity changes due to impact and => where the velocity changes due to gravitational acceleration.  You are the first person to say I didn’t put in gravitational acceleration in 3 months.

The top mass starts at 0 ft/sec and hits the second mass at 32 ft/sec.  The conservation of momentum changes the velocity to 10.67 ft/sec because it is a one ton mass hitting a two ton mass.  The three tons then falls 16 more feet accelerating to 33.74 ft/sec before impacting the next mass.

Would you be so kind as to understand what you are criticizing before you do so?

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Posted: 12 October 2008 07:45 PM   [ Ignore ]   [ # 281 ]
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psikeyhackr, I’m not going to argue with you. I understand the physics of this situation quite clearly, and I will be happy to explain it to you. If you are determined to believe that some mysterious force other than gravity caused the buildings to fall, be my guest.

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Posted: 12 October 2008 08:25 PM   [ Ignore ]   [ # 282 ]
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I got curious about finding an analytic solution to the problem instead of the messy numeric approach you take, and wrote up the equations. I first tried doing it with a standard integration, assuming a constant linear density. Unfortunately, although I was able to derive the integral, my calculus is too rusty to come up with the analytic solution. So I fell back on an incremental approach. The equation to use is this:

v(i+1) = (M(i)*v(i))/(M(i)+m) + g*h/v(i)

where v(i) is the velocity of the falling mass at the ith floor, counting downward from the initial failure point
M(i) is the mass of the falling body at the ith floor
m is the mass of a single floor
g is gravitational acceleration
h is the distance between floors

The time required to traverse h is simply:
t(i) = h/v(i)

and obviously the mass M accumulates as:
M(i+1) = M(i)+m

If we set m=1 for computational purposes, then M(0) is about 20, and v(0)=0

So plug in the values and turn the crank to get a final answer. It should be easy to do with a spreadsheet using the standard “Fill down” command.

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Posted: 13 October 2008 02:54 AM   [ Ignore ]   [ # 283 ]
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Chris Crawford - 12 October 2008 07:45 PM

psikeyhackr, I’m not going to argue with you. I understand the physics of this situation quite clearly, and I will be happy to explain it to you. If you are determined to believe that some mysterious force other than gravity caused the buildings to fall, be my guest.

Yes ... not just mysterious completely unbelievable (that a government as inept as Bush’s appears to be could actually competently arrange the destruction of the WTC & part of the Pentagon and make it look like an act of terrorism). Very mysterious ROFLMAO!!!!!

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Posted: 13 October 2008 12:40 PM   [ Ignore ]   [ # 284 ]
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Chris Crawford - 12 October 2008 07:45 PM

psikeyhackr, I’m not going to argue with you. I understand the physics of this situation quite clearly, and I will be happy to explain it to you. If you are determined to believe that some mysterious force other than gravity caused the buildings to fall, be my guest.

ROFL

So explain how missed my gravitational acceleration calculations.  LOL

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Posted: 13 October 2008 12:52 PM   [ Ignore ]   [ # 285 ]
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So explain how missed my gravitational acceleration calculations.

Your calculations are a mess. They may be right, they may be wrong, and it’s too much work picking through that mess to figure out whether you got anything right or wrong. I suggest that you use the system of equations that I offered—they’re much clearer and it’s harder to make a mistake using them.

It would also be useful if you could state exactly what it is you’re trying to prove. On the one hand, you say that the buildings came down too quickly. On the other hand, you say that you have accounted for gravity. But in fact, they fell down more slowly than they would have done in free fall. So what are you trying to prove? Please state a hypothesis that you are attempting to establish. That will give us a basis for analysis.

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