Mapping a Galactic Transit System

I love the London Underground and have a great fondness for wandering about the city with a tube map stuck in my pocket. My wife and I last did this a few years back, making an early March trip in which we rented a Bloomsbury apartment for ten days and hopped all over the area, station to station, emerging for blustery walks to various historical sites (we were both, at one time, medievalists), then ducking into nearby restaurants for tea and warming up, talking about what we had seen and examining the map for our next stop.

A map of the London Underground is a schematic diagram that has a beauty of its own, reducing a city beyond its topography to a sequence of formalized connections and zones. The fascination is in the abstraction of the familiar, rendering distance and space intelligible. Now look at what we might call a ‘tube map’ of the Milky Way, as produced by Samuel Arbesman, a postdoc at Harvard with an interest in computational sociology and, obviously, big maps.

Click on the image to see Arbesman’s larger version of it, which in turn links to a downloadable PDF. This is the route map of what Arbesman calls the Milky Way Transit Authority, inspired by his recent re-reading of Carl Sagan’s Contact and the notion of a vast subway handling galactic traffic. Remember its main hub?

And swimming into her field of view as the dodec rotated was… a prodigy, a wonder, a miracle. They were upon it almost before they knew it. It filled half the sky. Now they were flying over it. On its surface were hundreds, perhaps thousands, of illuminated doorways, each with a different shape. Many were polygonal or circular or with an elliptical cross section, some had projecting appendages or a sequence of partly overlapping off-center circles. She realized they were docking ports, thousands of different docking ports — some perhaps only meters in size, others clearly kilometers across, or larger. Every one of them, she decided, was the template of some interstellar machine like this one. Big creatures in serious machines had imposing entry posts. Little creatures, like us, had tiny ports. It was a democratic arrangement, with no hint of particularly privileged civilizations. The diversity of ports suggested few social distinctions among the sundry civilizations, but it implied a breathtaking diversity of beings and cultures. Talk about Grand Central Station! she thought.

Well, the London Underground was never like what Ellie Arroway saw, but I still love it. Ramping up to a galactic scale reminds me, too, of Jon Lomberg’s Galaxy Garden, which renders our vast city of stars in the form of a gorgeous botanical display. I think Arbesman is right in saying “…there is power in creating tools for beginning to wrap our minds around the interconnections of our galactic neighborhood.”

Maybe we’re at the dawn of the era when the galaxy will begin to be represented as a more or less familiar place, rather than a vague stripe of stars across the sky, all but unnoticeable unless you get away from city lights in many parts of the world. That sense of context, of our place within that part of the universe that is immediately around us, is one we need to explain and enhance for our children. Astronomy education can do this, and it doesn’t always hurt to include a bit of whimsy — check out Arbesman’s MWTA tote bags!