The diagram below shows the complexity, in terms of numbers of parts, of some human constructions. Interestingly, there is an approximate complexity plateau which starts at or before the Great Pyramid of Giza (constructed between about 2580 BC and 2560 BC, and composed of around 2.3 million stone blocks). The plateau continues through the dome of Florence Cathedral (brilliantly designed by Filippo Brunelleschi, made up of over 4 million bricks, and completed in 1436). A late member of the plateau is the Boeing 747 (first flown in 1969, and composed of around 6 million parts). The Great Pyramid required the resources of a nation, Brunelleschi’s dome those of a city-state, and the 747 those of a large company.
Somewhat less complex are the Antikythera mechanism and John Harrison’s H1 chronometer (a five-year effort by one man). The PDP-8/S (1966) and the original Apple Macintosh (1984) were widely popular low-cost computers. For those, I’ve interpreted “parts” as either transistors, individual bits of ferrite core memory, or bytes of semiconductor memory.
The recent iPhone 6s stands out from the simpler computers: the A9 processor has over 3 billion transistors, and the phone comes with at least 18 GB of memory. The iPhone 6s puts the power of a mid-80s Cray-2 supercomputer in a handheld device. Producing one requires the resources of an international network of specialised companies, with the processor and memory being fabricated in South Korea or Taiwan, the camera and display in Japan, and the accelerometer in Germany. The software is developed in the USA, and final assembly is mostly done in China. It seem unlikely that any one nation would be able to construct a device as complex as this.
Maybe I should get one.