linked - Investigating the Terror

of explosive damage.
By putting all of these things together and looking at the size of
the hole I estimated that the velocity of detonation was
somewhere between 14,000 and about 15,500 feet per second,
with a little bit of give on each side of that.
. . . .
For example, if we had C4 [a military ordnance] in that World
Trade Center basement, a quantity of it, of course the quantity
doesn't matter, over a hundred pounds, because the velocity of
detonation of the C4 is somewhere around 24,000 feet per
second, give or take, that explosive is very brisan[t], brisance
meaning that that shock wave comes out real quick. When that
shock -- and it doesn't last as long as a slower velocity
explosive. So when that brisance hit the target material like steel
-- if you recall in the one photograph where it looked like that
steel was torn -- we would see a lot more of that tearing, really
tremendous tearing damage in some of the heavier materials
like the steel.
If, for example, we go to a slower velocity explosive, let's say
something around 14,000 feet per second, when that detonates
we're going to get more of a pushing, a heaving effect. It's not
going to crack it hard. It's going to gradually build up, but still
very rapidly take hold of that witness material and give it a push
or a shove, and it's not going to crack that material as rapidly.
Q. Is that in fact the type of explosive damage that you saw?
A. The pushing and heaving is exactly what I saw in the World
Trade Center.
The problem with this testimony is that Williams never explains how the
observations compute to 14,000-15,500 feet per second. That he