The German chemist Fritz Haber proposed paying off the reparations imposed
against Germany after World War I by extracting gold from seawater. Given that
(1) the amount of the reparations was \(\$ 28.8\) billion dollars,
(2) the value of gold at the time was about \(\$ 21.25\) per troy ounce ( \(1
\text { troy ounce }=31.103 \mathrm{g}),\) and (3) gold occurs in seawater to
the extent of \(4.67 \times 10^{17}\) atoms per ton of seawater \((1 \text { ton
}=2000\) lb), how many cubic kilometers of seawater would have had to be
processed to obtain the required amount of gold? Assume that the density of
seawater is \(1.03 \mathrm{g} / \mathrm{cm}^{3}\) (Haber's scheme proved to be
commercially infeasible, and the reparations were never fully paid.)