Continuing the theme of exploring the exercises in Software: A Technical History:
Give an example of a specific physical phenomenon that software depends
Kim W. Tracy, Software: A Technical History (p. 43)
on in order to run. Can a different physical phenomenon be used? If so, give
another example phenomenon. If not, explain why that’s the only physical
phenomenon that can be used.
My short, but accurate, answer is “none”. Referring back to the definition of software I quoted in Related methods and tools, nothing in that definition implies or requires any particular physical device, technology, or other phenomenon.
Exploring the history of computing, it’s clear that the inventors and theoreticians saw computers as automation (or perhaps more accurately flawless repetition) of thought:
We may compare a man in the process of computing a real number to a machine which is only capable of a finite number of conditions…
Alan M. Turing, On Computable Numbers, with an Application to the Entscheidungsproblem (§1)
Or earlier:
Whenever engines of this kind exist in the capitals and universities of the world, it is obvious that all those enquirers who wish to put their theories to the test of number, will apply their efforts so to shape the analytical results at which they have arrived, that they shall be susceptible of calculation by machinery in the shortest possible time, and the whole course of their analysis will be directed towards this object. Those who neglect the indication will find few who will avail themselves of formulae whose computation requires the expense and the error attendant on human aid.
Charles Babbage, On the Mathematical Powers of the Calculating Engine
For any particular physical tool you see applied to computing—mercury delay line memory, “silicon” chips (nowadays the silicon wafer is mostly a substrate for other semiconductors and metals), relays, thermionic valves, brass cogs, hydraulic tubes—you can replace it with other tools or even with a person using no tools at all.
So it was then, when the mechanical or digital computers automated the work of human computers. As it was in the last century, when the “I.T.” wave displaced human clerical assistants and rendered the typing pool redundant, and desktop publishing closed the type shop. Thus we see today, that categorization systems based on “A.I.” are validated on their performance when compared with human categorizers.
Nothing about today’s computers is physically necessary for their function, although through a process of iterating discovery with development we’ve consolidated on a physical process (integrated semiconductor circuits) that has particular cost, power, performance, manufacturing, and staffing qualities. A more interesting question to ask would be: what are the human relations that software depends on in order to run? In other words, what was it about these computers, typists, typesetters, paraprofessionals, and so on that made their work the target of software? Can a different human relation be used?
