Ah, so mass does stay the same when an object is broken into many smaller pieces, and my response to the effect that this is false was correct.
What you meant to say, then, was something more like "mass
of a system does not stay the same when an object is broken into many smaller pieces,
and some of those pieces are removed from the system." That makes a lot more sense.
Do you see how you've just demonstrated that deliberately omitting important details and qualifiers can make the difference between making a reasonable truthful claim and an absurd false one? When you learn not to do that any more your life will improve in many ways.
Conservation of mass is applicable to isolated systems only. In the WTC collapses, matter is ejected outward in massive volumes.
How much matter, relative to the amount that is not ejected outward?
This is energy lost to the system.
How much energy, compared to the amount that is not lost to the system?
Furthermore, conservation of mass does not explain the change in force which would result from a change in the size and weight of the structure or object.
Despite the progress made toward clarity above, you're still confused on some points. When mass is conserved, so is weight, which is a force, and so likewise is the force that that mass exerts when forced to undergo a given acceleration.
For example, take two identical boulders, and grind one into sand. A truck carrying the sand will require the same amount of engine power and brake power to accelerate in any given way as the truck carrying the boulder.
What might be confusing you is confounding changes in the form of the mass (e.g. sand versus boulder) with changes in the time scale of a physical process involving that mass. It is certainly true that the boulder, dropped on a piano, will do more damage than the sand, poured in a slow stream onto the same piano. But that's not because of the shape, it's because of the timing. Slowly shift the weight of the boulder onto the piano over the same time span that you poured the sand onto the piano, and the damage will be similar in both cases. Likewise if you dumped all the sand onto the piano in the same amount of time it took the boulder to strike it.
In the wtc tower collapses, there was no opportunity for rubble broken from the upper or lower parts of the structure to trickle down gradually, a little bit at a time, so as to reduce its effects. It all fell at once, most likely in a mass that was considerably denser and less elastic than the original structures (since it was being compressed between any remaining intact upper structure and any intact floor below it). So no significant reduction (and most likely an increase) in the forces applied to the structure below would be expected as a result of the comminution of the components.
So, that leaves the "not a closed system" argument. Do you have a quantitative argument to make regarding the amount of energy and mass lost as a result of outward ejection of materials? Various researchers have used the distribution of the debris as a guide to making such estimates, and have not found any basis to conclude sufficient outward ejection to significantly affect the overall progress of collapse. It might be interesting to compare your calculations to theirs, to see if you have a better case.
Respectfully,
Myriad
