Imagine creating a device to keep track of time. A couple of ways to do this are: 1). Use a programmable computer to write code 2). Place a gnomon on a flat

Imagine creating a device to keep track of time. A couple of ways to do this are: 1). Use a programmable computer to write code 2). Place a gnomon on a flat plate to make a sundial The first way is the gate model, it's algorithmic, like Shor's algorithm. The second way is analog. There is no algorithm. The solution consists of simply measuring a shadow.