China and physics may soon shatter our dreams of endless computing power

In the 1950s I spent a significant chunk of my pocket money buying a transistor. It was a small metal cylinder (about 5mm in diameter and 7mm deep) with three wires protruding from its base. I needed it for a little radio I was building, and buying it was a big deal for a lad living in rural Ireland. My baffled parents couldn't understand why this gizmo their son was holding between finger and thumb could be interesting; and, to be honest, you couldn't blame them. Now spool forward six decades. The A13 processor that powers the iPhone that I…