A Brief History of the Megastructure in Science Fiction

I was recently reminded of the golden age of megastructure stories. As this is not yet commonly accepted genre shorthand, perhaps a definition is in order.

Megastructures are not necessarily simple. In fact, most of them have rather sophisticated infrastructure working away off-stage preventing the story from being a Giant Agglomeration of Useless Scrap story. What they definitely are is large. To be a megastructure, the object needs to be world-sized, at least the volume of a moon and preferably much larger. Megastructures are also artificial. Some…well, one that I can think of but probably there are others…skirt the issue by being living artifacts but even there, they exist because some being took steps to bring them into existence.

There may be another characteristic megastructures need to have to be considered a classic megastructure: absent creators and a consequently mysterious purpose. At the very least, by the time the story begins, the megastructure has been around for a long time.   If there’s an example of a story about the construction of a megastructure, I cannot think of it. Have fun pointing out the well-known books I have forgotten in comments!

While there were precursors, the ur-megastructure, the one that largely defined how authors approach megastructure-stories, was Larry Niven’s 1970 Ringworld. In it, Louis Wu and a collection of allies travel to a strange artifact 200 light years from the Solar System, a solid ring about 2 AU in diameter, clearly artificial and with a habitable surface dwarfing the surface of the Earth. No sooner does the expedition arrive than they are shipwrecked, forced to explore the Ringworld in person.

The general shape of the Ringworld ur-plot shows up in megastructure story after megastructure story. A mysterious object of immense size! An expedition, hastily dispatched to investigate! Survivors marooned! A dire need for sturdy hiking boots! And occasionally, Answers!

Niven very considerately followed his novel with a 1974 essay called “Bigger Than Worlds” (included in the collection A Hole in Space.). It’s a fairly comprehensive listing of all varieties of Bigger Than Worlds artifacts. About the only variant he seems to have missed was what Iain M. Banks later called an Orbital, the Ringworld’s smaller (but far more stable) cousin. I am not saying a lot of the authors who wrote megastructure novels after 1974 necessarily cribbed from Niven’s essay, just that I would not be surprised to find in their libraries well-thumbed copies of A Hole in Space.

Ringworld was followed by Clarke’s 1973 Rendezvous With Rama. Rama fell short on size but compensated with enigma. The Phobos-size artifact’s path through the Solar System allows the human explorers too little time to figure out what questions to ask, much less find the answers. None of their questions would ever be answered, obviously, as the very idea of a Rama sequel is nonsensical (as nonsensical as a Highlander sequel). Always leave the customer wanting more, not glutted on excess.

Bob Shaw’s 1974 Orbitsville featured a Dyson Sphere laid in deep space as a honey trap for unwary explorers. My review is here, but the short version is “Bob Shaw was a rather morose fellow and his take on why someone would go to the trouble of building a Dyson Sphere is appropriately gloomy. Be happy, at least, this isn’t John Brunner’s take on Dyson Spheres. Or, God help us all, Mark Geston’s.”

Fred Pohl and Jack Williamson’s 1973 Doomship begat 1975’s Farthest Star. They did Shaw one better: Cuckoo isn’t just a Dyson sphere. It’s a huge intergalactic spaceship. Pohl and Williamson were also the first authors, to my knowledge, to solve the gravity issue (that the forces within a shell cancel out, so there’s no net attraction between an object on the inner surface of a shell to the shell, only to whatever object—a star, say—is within the shell.) by putting an ecosystem on the surface of the vast ship. It’s a fascinating setting poorly served by the story Pohl and Williamson chose to set on it.

Tony Rothman’s 1978 The World is Round is set so far in the future that the explorers are humanoid aliens. It otherwise dutifully embraces the standard features of the megastructure sub-genre: explorers become aware of an artifact the size of a small gas giant, which they race to explore in the hope of enriching themselves. As so often is the case, the explorers who manage to survive the initial stages of the adventure end up doing rather a lot of walking. There is, at least, a functioning subway. There is an absence of proper documentation that would be shocking were it not a defining feature of the megastructure genre.

John Varley’s 1979 Titan featured a comparatively small megastructure, merely the size of a respectable moon. Again, the explorers end up marooned pretty much as soon as they reach Gaea but Varley managed to ring some changes on the standard themes of the genre. The first is that Gaea is a living being, artificial but alive. The second is that it is intelligent, able to answer questions when it feels like it. Sadly, Gaea is as mad as sack of weasels so the answers are not always helpful.

There is a steady trickle of later examples—Kapp’s 1982 Search for the Sun!, James White’s 1988 Federation World, Banks’ Orbitals and Shellworlds, Baxter’s Ring, Barton and Capobianco’s White Light, Niven and Benford’s Shipworld novels, and of course Charles Stross’ 2006 Missile Gap, which is without question the finest Locus Award-winning story inspired by a post of mine on a USENET newsgroup—but the heyday of the megastructure seems to be over. In part this may be because the current zeitgeist does not favour stories set on what are effectively massive infrastructure projects.  Mostly I think it is because the stock plot for megastructurestories is rather restrictive and authors have other chimes they want to ring.

One detail about megastructures that has puzzled me for some time is the incredible lack of women writing them. There’s nothing intrinsic to the concept that shouts “dude!” to me and yet, for some reason I’ve either never encountered a megastructure book by a woman or I managed to forget its existence. If you know of any examples, please do point them out to me in comments.

Originally published in January 2018.

In the words of Wikipedia editor TexasAndroid, prolific book reviewer and perennial Darwin Award nominee James Davis Nicoll is of “questionable notability.” His work has appeared in Publishers Weekly and Romantic Times as well as on his own websites, James Nicoll Reviews and Young People Read Old SFF (where he is assisted by editor Karen Lofstrom and web person Adrienne L. Travis). He is currently a finalist for the 2020 Best Fan Writer Hugo Award and is surprisingly flammable.



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