As I understand it, they were able to train and classify XOR using 32 of their breadboard nodes, which visually looks roughly a 1 metre square. XOR can usually

As I understand it, they were able to train and classify XOR using 32 of their breadboard nodes, which visually looks roughly a 1 metre square. XOR can usually be done with 1 or 2 neurons. And MNIST digit classification with ~25,000. Bringing all those numbers together we get 1 neuron = 32 nodes = 1sqm, would give a size of about a 900m square if breadboarded out for ordinary MNIST digits. (Assuming of course, no power transmission losses...!) I'm hoping, if not outright assuming, that I've made some kind of catastrophic error here.