Neal Stephenson studied physics before becoming a writer, and his fascination with the way science and technologies develop is a central theme in much of his work.
At an event in 2011, a university chief accused the author and other science-fiction writers of failing to pull their weight because they had not come up with big ideas to inspire researchers in the way Arthur C Clarke and Jules Verne had done earlier. The shaven-headed author’s response was to ask: “How tall can we build something?” and – 20km (12.4 miles) was the answer. That’s how high the tower he has proposed building will soar if the project ever comes to fruition. Such a structure would make it cheaper to launch objects into space, he says, thanks to fuel savings.
It’s a lofty goal. But creating a building more than 24 times taller than Dubai’s Burj Khalifa and not far off double the height commercial aircraft fly at is no easy task.
The idea of creating a building that would soar into the freezing heights of near-space involves many practical challenges. First efforts to envisage such a structure resulted in a design whose base covered more than 10 sq miles and whose bracing members at the lower level would each be longer than any existing bridge. Early estimates, created to illustrate the scale of the task, suggested up to 985 million tonnes of steel might be required – the world’s entire steel output was only 1.55 billion tonnes last year. Those involved are now exploring the idea of building sections out of different materials.
Perhaps a bigger issue is that the structure needs to withstand jet-stream winds of more than 500km/h (310mph). One idea to achieve this is to mount aerofoils on to its exterior – effectively wings that would use air pressure to create lift – in order to “fly” the upper floors through the wind. Another proposal involves attaching rocket jet engines to the building’s walls. One researcher estimated that the structure would need about 700 F-1 engines – as used in Nasa’s Apollo programme – to work, so another option may be needed.
“We are some distance from understanding the jet stream well enough to manage the natural risks associated with structural integrity,” adds Prof Keith Hjelmstad. “And the technical aspects are only a part of the question. Selecting a site out of the way of conflict and raising the capital required to build it are, in our current world, probably just as difficult.”
Even if all these obstacles are overcome there remains one further hurdle. With estimates of the cost spiralling up to $1 trillion, Mr Stephenson half-jokes that it is not clear how the owners would ever get insured.
Edited by Deskarati from Neal Stephenson on tall towers and NSA cyber-spies.