Re: Blast in OK City bombing. (was Terrorist Entropy vs...)

Eugene Leitl (Eugene.Leitl@lrz.uni-muenchen.de)
Mon, 5 Aug 1996 11:53:08 +0200 (MET DST)


On Sat, 3 Aug 1996, Kyle L. Webb wrote:

> Ian Goddard wrote:
> > [...]
>
> Ammonium nitrate and fuel oil is a disordered substance, thus having no
> preferred direction in its detonation. Unless the geometry of the bomb is
> such that it channels the blast wave, wouldn't the applied force be pretty
> much isotropic?

Not necessarily. NH_4NO_3 is a hygroscopic colourles crystalline powder.
The additive is usually a few percent heavy oil (e.g. diesel/kerosene).
Homogenous mixing of large batches is nontrivial. Moreover, the dispersion
separates automagically through gravitation (oil accumulating at the
bottom of the charge). The shape of the charge is nonspherical. The
position of the charge just a few m above ground can contribute to some
focusing.

'gene