From Scott Aaronson's blog:
There’s a finite (and not unimaginably-large) set of boxes, such that if we knew how to pack those boxes into the trunk of your car, then we’d also know a proof of the Riemann Hypothesis. Indeed, every formal proof of the Riemann Hypothesis with at most (say) a million symbols corresponds to some way of packing the boxes into your trunk, and vice versa. Furthermore, a list of the boxes and their dimensions can be feasibly written down.
His later commented to explain where he get this from: "3-dimensional bin-packing is NP-complete."
I don't see how these two are related.
Another question inspired by the same article is here.