The pin factory and the Universal Machine
A look at the future of 3D printing via the ideas of Adam Smith and Alan Turing
The Printers won’t kill the Pin Factory
To hear some of the talk around 3D printers one could be forgiven for thinking they’ll transform us all into a collection of skilled artisans creating in our bedrooms. Regardless of what one makes of other spectres that have been raised (neighbours running off 3D guns and the undermining of copyright) this seems an undeniably attractive image. Though it probably won't be quite like that in reality, for a rather old-fashioned reason.
One of Adam Smith's central insights in his 1776 founding work on economics The Wealth of Nations is that there are benefits of specialisation. To illustrate this, Smith gives the example of a pin factory where the making of pins is divided up into different stages, which workers specialise in: ‘One man draws out the wire; another straights it; a third cuts it; a fourth points it; a fifth grinds it at the top for receiving the head [and so on]’ and collectively being more productive than if each person had tried to make pins on their own. Many or all of these stages of production will have been replaced by machine, what has not changed however is the underlying idea Adam Smith is trying to convey. That it’s often better for us to try and specialise in different tasks.
I might, hypothetically, be able to use a 3D printer in future to create an object exactly how I want it, but that’s very limiting. A designer building on years of experience will have a far more sophisticated understanding of printers’ creative possibilities and be able to offer me a far richer array of things to print. It will therefore make more sense for me to print their design, than try and create my own.
A concern is that digital piracy will stop a market for designs developing. Perhaps it will prove impossible for paid content to subsist with pirated content, or for free designs to drive other revenue streams. The internet currently provides several examples suggesting business models like this can work, but time will tell. Regardless, it seems likely that 3D printers will only be very widely adopted if there are a large number of high quality designs available, and to produce such designs will probably require a dedicated community operating on a commercial and or opensource basis.
Specialisation aside, other benefits related to larger scales of production such as savings from bulk buying, exploiting synergies between different machines or being able to spread risks across a wide range of activities are unlikely to go away any time soon either. This is not to deny that 3D printers have great potential to change the means of production or the nature of what is produced. Smaller, more flexible, scales of production will probably lead to a far greater level of product customisation. 3D printing can reduce distribution costs increasing incentives to move production closer to the market and potentially reversing trends in offshoring. Innovation in 3D printer design, and online collaboration tools, may well eliminate certain skilled roles and greatly expand the scope of what can produced by individuals. Radical ideas of supply chains completely collapsing to the bedroom are though too simplistic.
The (underused) Universal Machine
But, it might be argued, suppose 3D printers become small, cheap and incredibly versatile, able to undertake any conceivable printing task? Won't every home have one, and won't we all be using them to unlock our creativity? Well, maybe yes to the former, but sadly there is rather less evidence that the latter will readily occur. This vision forgets that almost every home already has a device like that. It’s called the computer.
Alan Turing's perhaps greatest achievement was to mathematically define and demonstrate the power (and limitations) of computers. Turing developed an abstract model of computation known as the Turing Machine which he argued, and it is generally accepted, embodies the concept of all digital computation. Although there are an infinite number of possible Turing machines, Turing proved something remarkable. That there is in fact a kind of Turing machine (The Universal Turing Machine) that is able to simulate all the other Turing machines. There may be many different kinds of computational process, but all can be simulated by one suitably programmed machine: the computer. It is ultimately this mathematical truth, realised through our mastery of physics, engineering and computer science, that underlies the computer’s ability to do such a wide range of tasks.
Turing’s brilliant, abstract, mathematical machine of 1936 has gone on quite a journey to arrive at the point where almost everybody has one (or more than one), driven by many advances in technology and interfaces (von Neumann architecture, microprocessors, high-level languages, screens, keyboards, operating systems, the mouse etc.) and doubtless 3D printers will too - and probably over a shorter timescale. The fact, however, is that even though we already have a device that can do a vast range of creative activities, most of us forget we have this amazing resource on our desktops and use it to "surf" and send email. Most computers are never programmed directly by their users, or are used to their full capacity, and the same may well be true of 3D printers if they become ubiquitous.
Given this, experience suggests that 3D printing may not readily unleash a wave of creativity across the country’s households, but that’s not a good thing. There are understandable reasons why not everyone engages directly with technology, as Adam Smith pointed out, it makes sense to specialise, but it would be great if more people explored the huge creative potential of computers and 3D printers. The more people doing these activities the higher the chance of creating things people enjoy, the next [insert name of high-profile tech company] and wealth and employment for the economy as a whole. This is why initiatives to get more people engaged in technology, such as the Raspberry Pi and Nesta’s Digital Makers Fund, are so important. Program and print away.
 Similar conclusions were reached around the same time by Alonzo Church using a different approach that is less ostensibly connected with computers. The claim that Turing machines embody all forms of computation is as a result often referred to as the Church-Turing thesis.
 A key finding from Turing’s analysis is also that there are some things we will never be able to programme computers to do. This is a fundamental mathematical limitation of computers (at least as they are defined by Turing Machines\the Church-Turing thesis), not a technological limitation we can overcome.
A practical restriction on what computers can do is memory size. Turing assumed that his machines had access to an infinitely large memory, and computers’ finite memory limits their ability to undertake certain computational tasks, albeit that most users never hit this limit. Memory aside, there may be calculations that, while technically feasible, are sufficiently complicated that they take an impractical length of time to complete.