My tractor has never caught a virus. In retrospect, I saw that the day had neatly compassed the new and old economies, while highlighting the truth that the really important stuff endures. Physical work requires physical strength. Iron and steel require enormous energy for extraction and manufacture. But once made, a tractor holds its value, and incidental repairs don't come close to the cost of replacement.
Intellectual work requires intellectual nimbleness.
Easing the drudgery of manipulating symbols requires a palimpsest or a magic slate. Pencil and eraser were a vast improvement over charcoal or ink, and the pixel is better still. Because our brains are portable, tools that abet mental tasks should be, too, as well as quick. Such improvements dictate that old computers rapidly decline in value, and incidental repairs can soon exceed the cost of replacement. Through it all run ancient threads, the sun caught in plant and petroleum, released in the fires of engine or belly, ever bound up in the spinning of wheels.