North Tower Acceleration

[William Seger]

179. Stop it, you're fracturing me

PULVERIZE. transitive verb. 1. : to reduce (as by crushing, beating, or grinding) to very small particles.

I do believe that crushing, beating, or grinding concrete reduces it to very small particles by fracturing it. If you believe something different, then yeah, I can see why you didn't understand what I was talking about.

I also believe that the initial collision fractured the concrete into pieces of all sizes, which certainly included some pulverization but surely not all of the concrete was pulverized, so I do believe Ross is the one who is being misleading by calling all of it "pulverisation" (which I keep putting in quotes because of the exaggeration, not because of the British spelling).

I also believe there was a hell of a lot of crushing, beating, and grinding going on after that collision, before that concrete hit the ground, so a guess about how much fracturing there was in the initial collision by looking at what was on the ground is not going to be very accurate. But it really doesn't matter for Ross' argument, because he already made a guess about the velocity of the mass after the collision and used that guess and the momentum conservation law to calculate a kinetic energy loss.

I was indeed wrong to say that Ross had "another line" for concrete fracturing, er, I mean "pulverisation" when there were actually two lines, but it's been a few years since I looked at it. However, the point remains that Ross can't have his cake and eat it too: either he can claim an energy loss due to the inelastic collision or he can claim energy losses for specific deformation processes, but he can't do both.