Science and Science Fiction

September 9, 2014 in Interview, Responses

A lot of us who do science non-fiction work are inspired by science fiction. I grew up watching the original Star Trek, in the 1960s, and that vision of people working together towards a common goal and achieving something bigger than themselves resonates with me. The science fiction stories that inspire me focus on the best we can do as a species, instead of focusing on our failures.


Excerpt from The Lifebox, the Seashell and the Soul

September 9, 2014 in Related, Responses

(Thunder’s Mouth Press, 2005)

Pages 333-335

Language begins when social creatures actively communicate information to their fellows. A bee returning to the hive from a flower field does a waggle dance to tell the others what direction to fly in. An ant secretes pheromones to tell other ants that she’s recently encountered an intruder. We humans share information by grimacing, gesturing and making noises with our mouths.

Our languages have evolved both to describe the world around us, and to represent the thought patterns in our minds. “What are you thinking?” “Well, let me tell you.” In an essay on language, Jorge-Luis Borges quotes a relevant passage from G. K. Chesterton’s admiring biography of a Victorian painter, G. F. Watts, (Duckworth, London 1904), p. 88. I originally found the quote in Jorge Luis Borges, “The Analytical Language of John Wilkins,” in: E. Monegal and A. Reid, eds., Borges, A Reader (Dutton, New York 1981).

Man knows that there are in the soul tints more bewildering, more numberless, and more nameless than the colors of an autumn forest; … Yet he seriously believes that these things can every one of them, in all their tones and semi-tones, in all their blends and unions, be accurately represented by an arbitrary system of grunts and squeals. He believes that an ordinary civilized stockbroker can really produce out of his own inside noises which denote all the mysteries of memory and all the agonies of desire. (143)

My optimistic opinion is that, given time, willingness and a sympathetic listener, Chesterton’s stockbroker really can communicate the tints and semitones of his (or her) soul. It’s a matter of piling on detail, using analogies, and enhancing the words with the play of the voice. To ensure the transmission, the listener reflects back summaries of the message, so that the speaker can emend or amplify the explication as required. By the way, computer networks do something similar, with receiving nodes sending back requests for retransmission of packets of information lost on their way from the sending nodes.

Speaking of computers, it will be useful to describe a brief example that brings into relief a point about how language works. Suppose that a machine called, say, Eggpop has carried out a time-consuming computation to produce a high-resolution graphical image of the Mandelbrot set fractal. We can think of this image as being akin to an idea in Eggpop’s mind. Now if Eggpop wants to communicate this image to another machine, there are three possible messages Eggpop might send.

Language. A description of the algorithm and the parameters used to create the image.

Art. A file containing a pixel by pixel representation of the image.

Telepathy. A link pointing to the combined algorithm and quote in Eggpop’s own memory.

Language is an all-purpose construction kit that a speaker uses to model mental states. In interpreting these language constructs, a listener builds a brain state similar to the speaker’s.

Art represents a very different approach: an idea is rendered by images, sounds, sculpture, or the like. In many cases a picture is worth a thousand words ¾ and then some. But certainly there times where a few well-chosen words have deeper impact than a detailed image. In these cases, the words manage to trigger powerful, pre-existing thought modes.

And how about a human analogy to machines communicating by giving each other hyperlinks (and access permissions) to locations in their own minds? Conceivably we might someday come up with something like a brain-wave-based cell phone, which I like to call an uvyy. Perhaps with an uvvy you could reach out and sensually touch another person’s thought patterns rather than having to build your own copies of their thoughts based upon verbal descriptions.

In this vein, I can imagine a future in which people converse solely by direct links into each others’ minds. Language might become an outmoded social art — like handwriting or ballroom dancing! But I doubt it. I think language is so deeply congenial to us that we’d no sooner abandon it than we’d give up sex.

Although I just used “telepathy” for the notion of having direct links to another person’s thoughts, if telepathy is just a matter of having someone at a distance know what you’re thinking, then language already is a form of telepathy and a person walking down the street with a cell phone is essentially in telepathic contact with a friend.

I compare language to telepathy to point out how powerful language is. In the intimate conversations that you have with a lover, spouse or close friend, language feels as effortless as singing or dancing. The ideas flow and the minds merge. In this empathetic exchange, each of you develops a clear sense of your partner’s proto-self and core consciousness.

One imperfect feature of human language is that our rate of information exchange is limited to very low rates. Yes, you can send a multi megabyte-book manuscript by email in a matter of seconds, but the human listener at the other end will take hours or even days to read it. We’re stuck with low bounds on both the speed at which we can listen to someone talk and on the speed at which we can read with full comprehension. Telepathy might speed things up.

Rudy Rucker is a science fiction author, philosopher, mathematician, and one of the founders of the cyberpunk movement. He worked for twenty years as a computer science professor at San Jose State University and has published a number of software packages. His novels include Turing & Burroughs (2012), Jim and the Flims (2011), and Hylozoic (2009), as well as the Ware Tetralogy (1982–2000), a four-book cyberpunk series that won two Philip K. Dick awards.

Work-In-Progress Update: April 2013

September 9, 2014 in Related, Responses

Last week I had a really great phone call with Darren Petrucci, Suncor Professor of Architecture and Urban Design at Arizona State University, and we talked about previous work that each of us had done on border design. Previously, when I worked on the Border Town project, my goal was to create design interventions for people in border communities. It seems like this project will be an extension of that mission, while also combining what I learned from my thesis on the future of border security.

One thing Darren and I discussed was the fact that while governments are extremely good at inventing new initiatives for dealing with illegal activity at borders (Operation Gatekeeper in 1995, for example, or the “smart border agreements” devised under the Container Security Initiative, itself an offshoot of the then-new DHS), they have a terrible track record of dealing with legal travelers or legal trade. In general, most of these initiatives have to deal with things like hiring quotas and documentation, as well as the placement of specific border crossings to push undocumented migrants further into the desert so that the crossing itself becomes a deterrent. (The only thing this has done is increase the dependence of migrants on polleros, most of whom are in the employ of cartels, thereby opening an unintentional revenue stream for the very drug trade that the Customs and Border Patrol Agency is committed to stopping.)

It’s trite to suggest that the solution to all this is privatization, but it definitely came up. After all, the government has had its shot, and its greatest accomplishment seems to be the fact that border arrests have gone down 58%, while deaths at the border have continued to rise. And in fact, the diminishing arrests may have nothing to do with border security at all: a declining economy has proved the best deterrent. And legal migrants being educated in the US are choosing to leave, because the H1B visa and Green Card system takes so long. This was the thrust of the letter that Mark Zuckerberg and others wrote to Congress regarding immigration, and the pressure that the private sector is putting on government makes me wonder if they’re ready to take a more active role — beyond lobbying — in coming up with a solution.

One of the solutions Darren and I discussed was the creation of actual border towns populated by recruiters, put in strategic locations along the border and intended to act as training centers and prototyping facilities — for new products, new services, and new hires. In this regard they wouldn’t be too far off from the Center for Innovation, Testing, and Evaluation (CITE) city, in Lea County, New Mexico. CITE is an empty city that corporations can rent for the purposes of prototyping and research. If you want to test out your new driverless car system with real roads and real signals, it’s a good place to do it. What I’m wondering is if it’s time for something similar along the border, but populated by businesses, universities, organizations, and agencies who have a specific quota of H1B and other visas to hand out. I know, it’s weird, but we’re here to do weird.

Madeline Ashby is a science fiction writer and strategic foresight consultant based in Toronto. She is the author of vN (2012) and iD (2013), the first two novels in her Machine Dynasty series. Her fiction has appeared in Nature, FLURB, Tesseracts, Imaginarium, and Escape Pod. Her essays and criticism have appeared at Boing Boing, io9, WorldChanging, Creators Project, Arcfinity, and

Response to “Johnny Appledrone vs. the FAA”

August 22, 2014 in Responses

Lee’s story is very pertinent today. For example, there is a current legal case going on between the FAA and a hobby pilot who flew an unmanned aerial vehicle (UAV) near the University of Virginia. The FAA is trying to restrict how hobbyists and regular people can use UAVs. They actually have not come up with specific regulations yet, but they do not allow anyone to fly unmanned aerial vehicles without permission. Getting permission takes about 6-9 months and you can only get permission if you are a government entity (update: in March 2014, after this piece was written, the drone pilot won the case against the FAA). So the story is not just speculation about the future; this is something that’s happening right now.

Lee’s story does a great job bridging reality with science fiction. Most of the things that are talked about in the story are things that I will see during my lifetime. Anybody who’s in robotics, which is my particular field, has probably read Asimov and has been driven by his thinking. A similar dynamic exists in the field of space exploration: most of what people are thinking about right now has been driven by science fiction stories. If you look at what’s happening currently, where the technology is, how things are progressing, you can read it in some science fiction story that was written maybe 30 or 40 years ago.

When I first encountered the story, I was expecting it to be very futuristic – to happen maybe a hundred years in the future. But it struck very close to home. These are things that I think will happen in the next decade. So, this was a very realistic story. I was also expecting the story to focus on drones rather than people, so it was a nice surprise to that it was more about people and relationships, instead of just being about robots.

Sri Saripalli is an assistant professor in Arizona State University’s School of Earth and Space Exploration and the director of the Autonomous Systems Technologies Research and Integration Laboratory (ASTRIL). Before joining ASU, he was a member of the technical staff at NASA’s Jet Propulsion Laboratory.


Response to “Entanglement”

August 22, 2014 in Responses

Can you tell us a little bit about yourself and your work?

I was born in the high mountains of Switzerland as the son of a preacher and a teacher. I grew up close to Zurich where I studied Swiss Typography. I founded my first company by twenty, which went terribly wrong, moved out of Switzerland to work in a couple of different countries for a while, sometimes for companies, sometimes to volunteer, before coming back to Zurich, where I live now.

Back in Zurich I have founded a company called Etter Studio. The strategy is to stay small, work interdisciplinary, and create work which is sustainable from a commercial point of view, and if possible, make the world a tiny bit better at the same time. We work for global brands, such as Hermès, Puma, IBM, The Economist, and so on, but also for NGOs, scientific and governmental institutions. Lately we have started to create our own products, most notably with the iPad game Drei (, which seems to capture the spirit of the age. [Editor’s Note: Drei is a game that unites complete strangers from around the globe to collaboratively solve physics-based puzzles.]

What did you think of Vandana Singh’s story “Entanglement”? What did you like about it?

It’s baffling how two people who have never met can share very similar opinions about the world. I feel that I’m on the same wavelength with the author, Vandana Singh. But then again, if you believe that everything’s connected that’s not so surprising.

I liked many things, particularly the beginning and the ending. The beginning because I’m a sucker for anything that has to do with science and boats. I could just feel the mood that she described, drinking coffee on the deck, that subtle banging of the scientific tools hanging on the wall, following her thoughts, the rough and cold sea around her…lovely! The end, because I like the idea of a software that connects the global community at a very personal level.

Is there anything that you would change about the story?

I believe that stories like “Entanglement” are a very powerful tool to address climate change, because they share knowledge in an unpretentious and entertaining way. For me, the evidence of climate change was a bit too dense. I’d have moved the focus more onto the story and used it as ‘Trojan Horse’ to address climate change. Sometimes, while reading, it felt like it was the other way around.

Scientifically it’s incredibly sound. It’s clear that the author owns the topic; her story describes the complexity and the important nodes of the climate change issue. The only thing that I was missing was mentioning hydrofluorocarbons (HFC), which I believe are greatly underestimated in their impact on the global climate and deserve more attention. Also, there are simple and cheaper solutions to replace them.

What elements of “Entanglement” remind you of things that are happening in your field, or things that might happen soon?

I can’t see anything that isn’t true. My expertise is with technology, and technically it would be possible today to turn “genies” and the “Million Eyes Project” into reality. There would be some questions of privacy and security, but technically I don’t see a problem. Even real-time translation technology has had a big breakthrough in the last year [2013].

What technical or research questions relevant to your work does this story raise?

The question is more on the user side. In the story, interactions through this “genie” device were always very positive, connecting the right people at the right time. If you have ever used Chatroulette, which also connects complete strangers randomly via webcam, you know that we humans are far from perfect. There is a lot of boredom and nudity…and so forth. To create a positive experience you would need to do a lot of tinkering on the algorithm that decides which people should be connected when. This would involve many, many, many days of testing with as many random people as possible and analysis of why some people match and some don’t.

To make computers understand human emotions, moods and characteristics is an incredibly interesting field at the moment; that’s why pretty much all major tech companies are researching heavily in this field.

How does the story inspire you? Does it open up new questions or directions for your work?

The problem that humanity faces today is entirely new and hasn’t existed in our entire history. Previously, if a community chopped down all trees in their forest, they quickly saw and felt the consequences and they had to act (this happened so in Zurich a few hundred years ago).

Now it’s different. I eat a steak, which comes from a cow, the cow comes from, let’s say, Poland, where it has eaten loads of crops grown in Brazil, which means a forest had to be chopped down (or burned down), and that’s why a family in Bangladesh has lost their simple house to the floods because of the CO2 emissions created by my steak! It’s hard to see these connections and impossible to prove the precise causal links. To understand these new complexities, we need a new human consciousness. To understand that our actions have consequences, even though they are disconnected in time and space. This is also what we try to address in our work whenever we have the opportunity.

If there is one idea from “Entanglement” that you could make real today, what would it be?

Oh, I would love these methane eating bacteria – that would be a real treat!

Christian Etter is the founder of Etter Studio, an interdisciplinary firm in Zurich, Switzerland. His company specializes in projects combining technology and creativity, often with a scientific background.


Response to “Degrees of Freedom”

August 22, 2014 in Responses

What did you find most interesting about “Degrees of Freedom”?

What I found most interesting was the attempt by Karl Schroeder to really think about how the future of new media technologies can have an explicit impact on the way we do politics – specifically deliberative and democratic politics. There’s a lot of science fiction that relates to how technologies might encourage authoritarian politics, but not a lot about how they might bring about more positive ways that democratic deliberation might occur.

As a political scientist and a scholar of science policy, what elements of the story seemed realistic?

The things in the story that felt most real to me was not necessarily the technology, but rather the motivations of the folks who were engaged in the political process. The story features a number of people acting out of a political and communal vision, trying to protect values that they hold dear and, deploying the technologies that they have available to them to protect those values.

How did “Degrees of Freedom” remind you of issues in your own research?

In some of the work that I’ve done around the societal aspects of nanotechnology, we’ve attempted to devise new deliberative techniques that enable lay citizens to take part in discussions about the societal aspects of new technologies.

In one of those instances we organized a national citizens’ technology forum in the spring of 2008. It connected groups of citizens holding these deliberations in six different places across the country through what is by today’s standards (not to mention by the standards in the story), a very crude kind of software. Participants were able to text each other and engage via discussion forums discussion board across these various places. It was not seamless, to say the least: there were no visuals that went along with it and there were a lot of clunky things, but nevertheless we were able to come up with a process that gave the citizens in these six different locations some sense of what the folks in the other locations were thinking about, how they were thinking differently, to enable the citizens to interact with experts who were not in the same room with them either, and able to have, in retrospect, a fairly high-quality deliberation.

The software that we were using at the time was very limiting in terms of the kinds of interactions that we were able to facilitate. It’s very interesting to see this sort of informed speculation about how the visuals and the connectivity, but also the intelligence that exists behind the software and decision-making tools, like The Faces, might be able to break through some of the barriers that we faced in organizing this citizens’ forum.

How does the story open up new questions about science policy and public participation in science?

As a scholar, the questions that this story raises, if this were a real technology, would be: “What exactly is going on in the software, in the intelligence that sits behind the system? How is it programmed such that we can read the Dorians with such subtlety and guide ourselves to a decision?” From the legal scholar and activist Lawrence Lessig, we know that code is law – so what laws are being embedded in the code? Is it really as neutral as it’s made out to be?

David Guston is a Professor in the School of Politics and Global Studies, Co-Director of the Consortium for Science, Policy and Outcomes, and Director of the Center for Nanotechnology and Society at Arizona State University. His research focuses on research and development policy, technology assessment, public participation in science and technology, and the politics of science policy


Response to “Covenant”

August 22, 2014 in Responses

What I love about Hieroglyph and about the Center for Science and the Imagination is that I totally believe that you can’t have better futures without better dreams. With Hieroglyph, the idea is not that we’re utopians; it’s that we’re thoughtful about how things might go right. And that’s incredibly important. There are some turning points in history recently which were basically failures of imagination and failures of optimism. The challenge is for us to think big and think rigorously and think smart because lazy dystopianism is child’s play.

I read through “Covenant” several times asking myself, “Why did she choose that title?” A covenant is an agreement between two parties; it’s a legal term. I think what Bear is trying to communicate is that there is an agreement here between the protagonist’s two selves: the psychopathic male that she was and the new person she has become. If I were writing an undergraduate paper about this story – and I guarantee that there will be a whole lot of them – I would write about the covenant that is established between these two selves.

“Covenant” is such a well-done piece of fiction. It’s not at all a utopian vision, nor is it dystopian. It walks the line very nicely between portraying a future that’s great, that’s really aspirational and one that’s horrible, that you’d never want to see happen. It walks that line in a lovely fashion, and that’s one of the things that I like about it most.

Joel Garreau is the Lincoln Professor of Law, Culture and Values at Arizona State University’s Sandra Day O’Connor College of Law. He is the author of the books Radical Evolution, The Nine Nations of North America, and Edge City: Life on the New Frontier.

Joel Garreau is a student of culture, values, and change. Joel's latest book, Radical Evolution: The Promise and Peril of Enhancing Our Minds, Our Bodies, and What It Means to Be Human, takes an unprecedented, sometimes alarming, always spellbinding look at the hinge in history at which we have arrived. For hundreds of millennia, our technologies have been aimed outward at altering our environment in the fashion of fire, agriculture, or space travel. Now, for the first time, we are increasingly aiming inward at modifying our minds, memories, metabolisms, personalities, progeny and possibly our immortal souls. Radical Evolution is about altering human nature -- not in some distant tomorrow, but right now, on our watch.

“The Day It All Ended”: Thoughts of a Technologist

August 22, 2014 in Responses

Brad Allenby, President’s Professor of Civil, Environmental and Sustainable Engineering; Lincoln Professor of Engineering and Ethics; Professor of Law, Arizona State University 

The most immediate response to the nice little piece by Charlie Jane Anders, “The Day It All Ended,” is pleasure at reading an optimistic story. This is more rare than you would think, primarily because writing dystopian fiction is so much easier than writing happy fiction. Dystopian fiction wins you prizes and the adulation of millions – to the extent they still read, of course – whereas cheerful stories, or, worse yet, actual humor, may get you an occasional shot at The New Yorker, but you will never be taken seriously. Exploring noir urban niches, and the dark side of the human soul, are understood to signal engagement with what it means to be truly human, and to establish one as an intellectual struggling, often painfully, with ultimate meaning, angst nipping at your bloody ankles. Optimism not only confuses people, but, especially in our cynical age, lies entirely without the reigning zeitgeist. So hats off to happy. And yes, you might mutter that the theme of environmental redemption is somewhat trite by this time, but that didn’t seem to stop the movie Avatar from being quite a success, and I don’t see why it should be held too strongly against this work either.

Of course, this is also a pretty obvious example of the “technology as savior” genre; it can’t literally be deus ex machine because the deus is us. And that’s an interesting twist, isn’t it? The technology itself is neutral; it is the intentional design, and the institutional and individual intent, that create the desired O’Henry plot shift. Leaving aside for now the difficulty of developing and deploying such a technology, this reflects the more fundamental reality that Cassius nicked Brutus with: our problems generally arise not from our stars, or our toasters, but ourselves. Consider a recent example. There is absolutely nothing wrong with making ethanol out of corn. Indeed, without it life in the American Appalachians would have been even harder than it was, and NASCAR would not be with us (the origins of NASCAR lie in the hot cars and crazy drivers that ran illegal moonshine from the stills to the customers, a process that makes no sense without the moonshine in the first place). What has made corn based ethanol a questionable technology, in economic and social terms, is the massive scale-up implied by the legislative demands that a significant percentage of American gasoline be ethanol. That’s a political decision, and can’t be blamed on the technology without a certain level of mendacity.

In other words, Anders has not taken the easy road of blaming technology for dystopian effects; indeed, he is careful to have Jethro note that it was human nature that required the subterfuge of building salvation into the superficially destructive technology systems that DiZi sells (for those of you who follow such things, this is not unlike the Matrix complaining that it set up a utopia for humans, only to discover they couldn’t handle it, and needed unhappiness to be happy. No wonder our computers don’t understand us.). Humans are the problem, and humans are the solution. This is a useful if subtle rejoinder to the myriads who, by blaming technology, neatly create a gestalt where they have no responsibility. Technology is a human activity; indeed, is core to being human, as Hannah Arendt and Max Scheler, among others, try to remind us (homo faber).

More subtle still, Anders is implying quite a radical worldview. In his story, it is clear that humans have grown to dominate the planet and many of its systems: the obvious ones of global cycles of carbon, and biodiversity, and environmental damage; the less obvious ones of material flows (where does all that technology come from, after all?), and economics, and psychology, and institutions. Designing technology is, in fact, designing the world. This is a terraformed planet. We get so used to this in fiction that we tend to forget – or, perhaps, cringing with guilt, we are unable to admit – that this is precisely where we are right now.

And what is critical about design? It is this: if you design something, you are responsible for it. You cannot evade that responsibility. DiZi is blamed for producing the technologies that are apparently destroying the world, and appropriately so; and DiZi is, in fact, going to get the credit for saving the world. This, again, points back to many today who, in seeking to blame various institutions, people, and factors, refuse to accept their responsibility. Why do you think the world looks the way it does? Because ocean-going sailing ships combined with corned gun powder and cannon combined with expansionist European cultures sailed around the world; because coal and steam and railroads pushed humans into modernity; because jets and modern finance and intricate information systems and networks keep us there. Maybe a hundred years ago, you could pretend this wasn’t a terraformed planet. You can’t now. Not really. Not without some serious evasion of responsibility.

But come on. You want a technologist to troll through this story, bit by bit, and drily demolish the technological assumptions that lie behind it. I’ll be glad to make a few points, but let’s be clear that they don’t really matter. If this were an engineering article, I’d peer review it. It isn’t, and I won’t. That said, there are a couple of nice points to this piece. For example, the reference to being able to scrub carbon dioxide from the atmosphere using amines (and sodium hydroxide) is real: those technologies now exist (although you couldn’t deploy them as suggested in the story, because you’d need too much amine, so you need to cycle and regenerate your capture chemical). Whether this makes climate change a matter of choice – a global design decision, as it were – is a matter of debate right now, involving complicated issues like how much underground storage there is for the relatively large volume of liquid carbon dioxide you’d generate by deploying such “carbon capture” technology. Also, I did like the part about copyright pirates needing to put in the “hidden design” elements – if I were a pirate, it is precisely avoiding the costs of that apparently unnecessary technology that would give me a cost advantage. Moreover, if DiZi had the power to impose their full (and apparently inefficient) design on me, they could probably stop me from pirating in the first place. Makes me think they’re also playing games with the antitrust laws. But that’s a nit, and I for one am glad to live with it in the interests of a more coherent story.

Perhaps most interesting is the implicit assumption that you can reverse the path we’re on – that removing carbon dioxide will move us back towards a more stable, and more desirable, state. That isn’t necessarily true. Complex systems like the climate display what’s known as “path dependence,” and that means that what the Jethro and DiZi are moving us towards is a new state, not anything we’ve known in the past. You can’t go home again. We will never have the world we had 100 years ago. We might go back to 300 or 350 ppm of carbon dioxide (we’re now nearing 400), but we won’t go back to the climate we used to have. It will be a new climate, and undoubtedly spring new surprises on us, even if and as we lower carbon dioxide levels. The dirty little secret of climate change is that we’re already on that boat, we have been for a while, and there’s no getting off. You will never have the stability that some are claiming we can retrieve. Politically, perhaps you have to say that. But it’s not how this world you’ve already created works. That world is your design space now. You can no longer evade the responsibility that comes with it. And you can’t go back. Never.

We are all DiZi. Welcome to World 2.0.


Response to “Girl in Wave : Wave in Girl”

August 22, 2014 in Responses

As a researcher in the field of personalized learning technology, what rings true about “Girl in Wave : Wave in Girl”?

The story referenced using brain data to provide a fine-grained assessment of student capabilities, and this is indeed the sort of research that’s currently being conducted in my field. In addition, the story contains the paradigm of having a mentor work with a child one on one, identify which learning materials to present next, and help the child realize his or her own learning potential. This is both a primary objective of researchers developing personalized learning technologies, and how several educational technology researchers see the role of teachers in the evolving technological environment.

What technical or research questions relevant to your field does this story raise?

The story prompts several relevant research questions:

  1. How could advances in neuroscience be leveraged to accelerate learning?
  2. How can “Mentors” be supported in providing individualized guidance to their students?
  3. If you could build the kind of intervention presented in the story, on who and where should it be used?

Does the story open up new directions for your work?

I am working on a project to assess learning using brain data, and this story does prompt me to further consider a natural extension of that line of research – can the brain be manipulated to accelerate learning? The idea of targeting literacy for such a broad intervention is one that I have been playing with, and I think the story illustrates how effective and important that might be. Finally, the idea of having mentors share memories and experiences with their students is an interesting one. It might be productive to think about how lower-tech versions of that concept can be put in practice.

Erin Walker is an Assistant Professor in the School of Computing, Informatics, and Decision Systems Engineering at Arizona State University. She orchestrates the design and implementation of cutting-edge personalized learning technologies, and then evaluates them for their real-world impact.


Structural Design of the Tall Tower

August 22, 2014 in Responses

The challenge of building tall structures has lured people like me into the profession of structural engineering for a long time. Managing our gravitational well in order to elevate usable space above the surface of the Earth is harder than it looks. And it’s not just gravity holding us down. The ebbs and flows of that thin sheet of fluid that is our atmosphere and ground shifts caused by tectonic movement create a difficult physical environment for building tall.

Despite training for the moment for my entire career, I was a bit stunned when Neal Stephenson asked me if a 20 km tall tower could be built. As a structural engineer I was still basking in the glow of the achievement of the Burj Khalifa—the current world’s tallest building standing 830 m tall. The notion of creating a structure 25 times taller than the tallest structure in the world was at odds with the gradual increments that have long characterized the evolution of tall buildings and long bridges. What? Do that next?

Neal had been inspired by a speculative paper from about a decade earlier—written by scientist and science fiction writer Geoffrey Landis—that claimed a tower 15 to 25 km high could be built from steel. A tower of that height could double the payload to orbit of a conventional rocket, he argued. The proposal that Landis had made appears to have been based on the assumption that, at a given level, the structure need only provide vertical resistance to the accumulated weight of the tower and payload above it. Engineers basically manage force by increase resisting area to reduce stress. In essence, Landis had proposed a vertical column with cross sectional area large enough to keep the stress below the available strength of the material. The weight of the resisting material gets to be a large part of the load. If you add material to reduce stress you also add to the cause of that stress. The result is an exponential cascade of material from top to bottom. Steel is strong, but it is also heavy. This simple model suggests that the total weight of material required is W = P (eµ – 1), where P is the payload at the top and µ = ρh/σ is the ratio of the density times height to the strength of the material—a sort of characteristic number of the tall tower. So the weight of material is basically the payload multiplied by a factor that gets exponentially large as the height goes up. If you want to carry no load then you need no material. One key engineering challenge is to figure out what P should be. How much does Cape Canaveral weigh? The Burj Khalifa weighs 0.5 million tonnes empty. So to put the Burj Khalifa up on top of the tower would require about 5 million tonnes of the best steel you can get. The upshot of these “back of the envelope” figures is that the 20 km tower seems very doable. That might have been the inspiration of Landis’s comment that the tower would be easy to achieve with today’s materials.

The simple Landis model gives us a baseline number for what it might take to realize the tower, but it ignores the lateral forces caused by wind and the possibility of the tower buckling under its own weight. To have lateral stability the tower must have bending resistance. Now, not only is the area of material important, so is its distribution. The tower needs girth.

The main design problem is to determine the shape that minimizes the weight of material while providing adequate strength. We narrowed the design space by considering symmetric towers with circular plans because we had no good reason to assume that the wind would blow in a particular direction, but we allowed for the possibility that the radius of the tower could vary with the height. The tower would need to have a wide base to resist overturning, but should be narrower in the upper reaches to project a smaller area in the most intense winds.

The tall tower will extend into the jet stream—a wind environment far more demanding than any we design for on the surface of the Earth. Some data indicated that the wind velocity would peak at about 90 m/s at about two thirds of the way up from the base. The wind load model we adopted was fairly primitive, but included the variation of air density with height along with the variation of wind velocity. The force on the structure is the accumulation of the forces on each member of the structure. We sought a design that would catch the least wind, narrowing the neck of the tower in the most intense portion of the jet stream.

While some data are available on winds in the troposphere, it is generally not tailored to what a structural engineer needs to know. It is a basic truth of structural engineering that the structure will be exposed to the environment all of the time and probably for hundreds of years. There is no instant in all of that time that can be passed off as insignificant. The structure will have to bear it all and while the most intense loads might be rare, the likelihood of occurrence over the lifetime is significant and the consequence of being unable to meet the demands that nature serves up are dire.

To advance the design at a more refined level, we developed a reticulated model, grafted some of the shape assumptions from the simpler models, and added a simple optimization engine to keep the stresses below allowable levels for the material for each member. Even at this more refined level the model blurs many details. Neal had always imagined that the tower would need to have a “fractal” structure (like the Eiffel Tower). What that means is that the tower would comprise mega-members that would be made of smaller members (laced together in some sort of trussed configuration) and those smaller members would be made of members smaller yet. And so on until the members that you actually build with can actually be made (and lifted). One consequence of the fractal geometry is that not all of the material can be oriented in the optimal direction (e.g., vertical for vertical loads). Some of the material must be invested in bracing—the members must be tied together to transmit the forces of wind and gravity over the structure so that it can mobilize its structural resistance.

For the reticulated model we created a design that would allow a variable number of levels (like stories in a tall building except that each “story” in the tower is about the height of the Burj Khalifa) and a variable number of primary columns. We imagined the plan as concentric circles to give the tower a “wall thickness.” At each level we created a truss ring that would transfer the loads at that level across all of the primary columns. The tower radius builds from a broad base (covering about 25 km2 in recent designs); it tapers in the region of the jet stream and blossoms at the top to provide usable real estate. With a four-sided geometry the tower looks a lot like the Eiffel Tower (except for the flair at the top)—an inevitable consequence of the forces it must resist. For a given geometry we optimized the structure with an algorithm that simply put more material in areas where stresses were high and took away material from areas where the stresses were low. Hence, for a given geometry we could find the minimum amount of material required. A recent design suggests that we are in the neighborhood of 250 million tonnes of steel—a healthy fraction of world annual steel production.

The truss geometry provided a sort of “level-zero” layout of the fractal structure, but it did not explicitly model all of the additional fractal levels. For a tower with twenty levels there are about a thousand members. In a fractal structure each member replicates the geometry of the larger structure. Therefore, modeling at the next level of the fractal geometry would have a million members. One more fractal level would give a billion members. An investigation of the fractal nature of the structure revealed an important result—as the number of fractal levels increases the wind area of the members also increases unfavorably. While the fractalization allows the wind to “blow right through the structure” it traps wind on the way in and on the way out. The fractalization thins out the members but there are more of them and member stability requirements at the smallest level determine the exposed fractal area. The implication of this observation is that the main members would likely need to be enclosed in a sheathing to reduce the wind drag. The demands of the wind have fostered interesting speculation about whether or not it is possible to use aerodynamics to help mitigate the wind induced stresses. The wind could be employed as a passive system that mobilizes uplift when needed most.

At present the tower is conceptualized only at the level of broad brush strokes. The design of the tower has opened areas of fundamental inquiry into the nature of the jet stream and the nature of air flow around and through fractal structures. Many design questions remain. A method of construction is yet to be devised—it is difficult to imagine the traditional steel worker toiling at minus 60 Celsius in air so thin that a Nepali Sherpa would be left gasping. That paradigm will need to give way to a robot-based approach (or perhaps even more clever strategies). The foundations of this enormous structure will bring unprecedented challenges to geotechnical engineers. What about transportation? Imagine a train system spiraling around the exterior of the tower. Imagine an airport two kilometers above the surface of the Earth.

It is evident that the lightest structures have the coarsest fractal geometry. But the horizontal bracing members at the first level of a twenty-level tower with five sides are longer than the longest bridge span in the world today. Each member will be a monumental record-shattering design in its own right. We still have to figure out how to do that. And the details are mind-numbingly complex. The basic geometry of how the members come together to form a structural joint capable of transmitting the huge forces is a challenge. A strategy for joining the members to form the structure is not solved and is made more complicated by the very cold temperatures in the upper reaches of the structure. And questions about the integrity of the structure in the event of an attack or natural disaster remain unresolved. The ordinary strategy of adding redundancy brings enormous additional weight.

This journey to wrap my mind around the possibility of the tall tower has caused me to recalibrate nearly everything I have ever thought about building tall. Along the way, every time my engineering sensibilities said “no” I would struggle back to “why not?” The idea is just big enough to keep you from trying to extend what has been done just a little bit further—it is an idea big enough to drive new thought.

Is the Tall Tower possible? Yes, theoretically. Is it feasible? Who is to say? That is more a question of human will than anything else. We still await the flood of ideas for use of the tower, and therein lies the case for building it. Oh, and by the way, if you put more stuff on the tower we will need to increase the size a bit.

Hjelmstad on Stephenson – Structural Design of the Tall Tower

Hjelmstad's research focuses on computational mechanics, earthquake engineering, stability of structures, optimization, structural identification, nondestructive evaluation of large structures, and numerical simulation of complex structures. He is a member of several professional associations for engineers and serves as associate editor of the Journal of Constructional Steel Research and the ASCE Journal of Structural Engineering.