While this is certainly a great trick (my favorite version of it is the use of soap bubbles to solve the traveling salesman problem) this solution is certainly

While this is certainly a great trick (my favorite version of it is the use of soap bubbles to solve the traveling salesman problem) this solution is certainly no better than what you would achieve with an optimization that runs on a digital computer (and very often it is much worse, given the advances in numerical optimization). There is one very general problem with these "analog" solutions to optimization problems: nature (i.e. the analog computer) quickly finds a local minimum and it does not bother to find a global one (or as the sibling mentioned, it finds a stationary solution, not the true minimal solution). There are tricks you can use to try to search for a better minimum, but all of these tricks are applicable to the digital computer as well. Which is really exciting: you get to talk about annealing and how it works the same in metallurgy and in numerical optimization. Even more fascinating, you get to talk about how a whole host of diseases are inherently due to this "failure of convergence" of analog computers: prion diseases would not exist if analog computers (our cells) folded their proteins to the true minima.