[ctdonath]

I'd wondered that too. Also wondered how transparent the glass would be: assuming the point would be rapid mass heating of the desert/beach in question a la nuclear weapon, the lack of material purity and uncontrolled heating would result in pretty poor glass, likely opaque. Trinitite isn't clear.

Even if P=NP, some problems still take a whole lotta work to solve, and "shortcuts" aren't much faster.