A Subway Metaphor

Many years ago I read a science fiction story which has always stayed with me – although I’m buggered if I can remember the title or the author.

It was set in the not too distant future. Another new line was about to be opened on the New York City Subway [In the comments Rozallin points out that it was, in fact, probably Boston and not NYC]. Mathematicians were warning that the line shouldn’t be opened as every new line increased the complexity of the network and they had calculated that opening this particular line would push the network over some limit and would make it theoretically unsolvable. They worried that the safety of passengers couldn’t be guaranteed if they were travelling on an unsolvable graph.

Of course, the mathematicians were ignored. And, of course, trains started going missing soon after the line was opened. And that’s where our hero (a kind of topological Indiana Jones, if I recall correctly) came in.

For some reason, that’s the image that sometimes pops into my head when I’m working on large application that has had random pieces of code added to it by various people over long periods of time. I worry that the system will eventually become so complex that any train (or, more likely, CPU) that is set running on it will vanish into the depths of complexity, never to be seen again.

I had that feeling particularly strongly this afternoon. This system really needs to be brought under control.

6 thoughts on “A Subway Metaphor

  1. Could the short story you’re referring to be “A Subway Named Möbius” by A. J. Deutsch? It’s set in Boston rather than New York City, but the plot sounds identical otherwise. I read it many years ago in a 1950s SF anthology borrowed from the library, and it’s stayed with me too.

    Rosellyne Thompson

  2. In Boston the layout of the subway system is complicated enough that the scenario in that story is not too hard to imagine!
    I’ve lived here all my life and still get lost in the multi-level maze that is the Park Street station…

  3. Oh, that sounds very likely. Thanks for pointing that out. I’ll have to track down a copy of that story and re-read it.

  4. Boston has nothing on the Victorian maze that is the London Underground. Throw in the DLR and London Overground lines (since it’s all treated as a logical whole on the maps and for ticketing purposes) and the mathematician in question will be quickly curled into a ball, crying.

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