Thursday, August 26, 2010

Body Worlds

Yesterday, Stefan and I went to see the "Body Worlds" exhibition, which is currently in Offenbach, close to Frankfurt, Germany. Body Worlds is a traveling exhibition that displays human bodies and body parts that have been preserved using a technique called plastination. Basically, it works by removing all bodily fluids and fat from the tissue by washing it out with acetone, and then replacing these fluids with silicone. That is to say, the exhibits are not anatomic models but actually real. The method of plastination used for these purposes was invented by Gunther von Hagens, then at the University of Heidelberg. His work there likely was inspiration for the horror movie "Anatomy," starring Franka Potente, which still causes me the occasional nightmare.

The exhibition itself was absolutely non-nightmarish. It had in fact a high educational value, and at least for me no yuck-factor. Besides that, it also had a missionary theme, that of documenting and explaining the process of aging and not only the complexity but also the fragility of the body. Besides many whole-body exhibits in fancy positions - dancing, playing saxophone, jumping over fences, during intercourse (must be 16 or older to see that) - they had all organs separately, some showing various illnesses and diseases (fatty liver, cancerous uterus, smoker's lung), as well as artificial joints. Some of the organs were cut into small slices or into half, so you could see inside. It is quite amazing really, to see all the muscles, bands, and nerves. Most stunning I found the capillary system that leaves behind the shape of the body after plastination (see picture to the left, more here).

It is not allowed to take photos of the exhibits. The ones you see here are from this and that url and there's some more on the website Alternatively, do a Google image search for Body Worlds and get a nice selection.

What I found somewhat annoying about the exhibition is that in all of the full body exhibits there were necessarily parts missing for better visibility (or possibly because they were just missing? Who knows what these people died from.) To begin with, most of the skin had been removed, but sometimes one or the other muscle, or this or that band. Unfortunately, there was nowhere to find a detailed explanation of what parts had been removed, so I was sometimes left wondering if there shouldn't be another muscle on that leg or another part on that spine or so. Also, I could have done without the photos of happy 100 year old men water skiing, proclaiming that happiness is the key to a long life. On the other hand I learned one or the other thing. For example, I wasn't aware the liver lies to closely below the diaphragm. And did you know that your testicles are doomed to shrink after you've passed your mid 40s? Or, more amusingly, that two centuries ago it was believed sperm is produced in the brain. Because, you see, that's were the soul is located and how could it be produced elsewhere. (Of course today we're more enlightened and know that the male soul sits in the testicles ;-).)

The bodies that are being used for plastination stem from people who donated them during their lifetime by signing the necessary forms. You can indeed donate your own body if you want to be conserved for educational means. Presently, there's more than 10,000 people who have signed up, and I suspect that most of them will not be used for exhibitions but rather for anatomy courses. On the other hand you might become famous post-mortem on Lady Gaga's stage. Apparently, the Lady has expressed interest in a decoration consisting of human bodies. In the exhibition guide, there's a selection of donors summarizing their motivations, which ranges from a love for science over some sort of immortality to admiration of von Hagens' work. The anonymity of the endproduct's origin I guess sorts out most narcissistic motivations. As to me, I'm signed up for organ donation, in various countries, and prefer to maximize my educational value during my lifetime.

Monday, August 23, 2010

Testing the foundations of quantum mechanics

If you know one thing about quantum mechanics, it's Born's rule: The probability of a measurement is the square of the amplitudes of the wave-functions. It is the central axiom of quantum mechanics and what makes it quantum. If you have a superposition of states, the amplitudes are sums of these states. Taking the square to obtain the probability means you will not only get the square of each single amplitude - which would be the classical result - but you will get mixed terms. These mixed terms are what is responsible for the interference in the famous double-slit experiment and yield the well-known spectrum with multiple maxima rather than one reproducing the two slits, as you'd get were the particles classical. (Dr. Quantum shows you what I mean.)

This rule has been implicitly tested countless times since it enters literally every calculation in which quantum effects are relevant. But it is not usually tested for parameterized deviations like, say, Einstein's field equations are tested for such deviations. Now however, a group of physicists (from the Institute for Quantum Computing and Perimeter Institute in Waterloo, Canada, the Laboratoire the Nanotechlogie et d'Instrumentation Optique in Troye, France, and the Institut für Experimentalphysik in Innsbruck, Austria) has tested Born's rule for deviations stemming from higher order interference which serves to constrain possible modifications of quantum mechanics. Their results were published in a recent Science issue:

The short summary is that they haven't found any deviation to a precision of one in a hundred. But their method is really neat and worth spending a paragraph on.

The experimental setup that the group has used is a tripe-slit through which pass single photons. If one computes the probability to measure a photon at a particular location on the detector screen in usual quantum mechanics, you square the sum of the wave-functions originating from each of the three slits. You get several mixed terms, but they are all second order in the wave-function. If Born's rule holds, this allows you to express the probability for the three-slit experiment as a sum of probabilities from leaving open only one of the slits and leaving open combinations of two slits. Thus, what the clever experimentalist do is a series of measurements leaving each single slit open, all combinations of two slits open, and leaving all three slits open, and see if the probabilities add up. And they do, to very good precision.

So, there's nothing groundbreaking to report here in terms of novel discoveries, but I very much like the direct test of the foundations of quantum mechanics this experiment constitutes. I think we could use more tests in this direction, and higher precision will come with time.

Friday, August 20, 2010

Book review: You are not a Gadget by Jaron Lanier

You are not a Gadget - A Manifesto
By Jaron Lanier
Knopf (January 12, 2010)

Jaron Lanier is an interdisciplinary computer scientist who doesn't shy away from also crossing borders also to the arts. He could probably be described as a creative intellectual, is known for his work on virtual reality, less known for his music, and now he has written a book. More details on Lanier's bio are on his website.

Lanier is a man with opinions, and that's basically what his book is about: Despite it being called "A Manifesto" what it really is is a collection of opinion pieces. Lanier is a skeptic, and concerned about many developments in software and information technology and their impact on human societies. I am very sympathetic to the points he is trying to make. Unfortunately, he doesn't make them well.

Lanier for example bemoans the "locked in" effect in which a piece of software, despite far from being optimal or even being plain annoying, becomes so wide spread that at some point it is more or less impossible to replace or change it; it simply would be too much effort. That is of course true, but it is hardly a new problem of software in particular. The same problem has hindered and does hinder progress in many other aspects of our life. Take tax laws for example. A mess. You want to throw them out and start all over again from scratch. Yet, too much effort and resistance. In practice, you fiddle something here or something there. Or, even worse, take norms and standards. Surely it would be less annoying if the world could agree on one paper format or one standard for power outlets. But the effort for such a change would be enormous. That is not to say that Lanier isn't making a correct point. It is a good point and one that we should pay more attention to. It's just to say, he misses the larger societal context and complains about an ancient problem without offering any new insight about it.
"If you love a medium made of software, there's a danger that you will become entrapped in someone else's recent careless thoughts. Struggle against that."

Another large concern of his is that the present organization of the internet, the spread of easy-to-use templates as well as making money per advertisement hampers creativity.

About the former point: it is of course true that the availability of default websites has decreased expressions of individual design. On the other hand, it's what allowed the vast majority of people to set up a website in the first place, and let me add that I know plenty of people with a PhD who insist they aren't able to understand html or css-style sheets. It's a matter of convenience. And in addition, it is actually a great relieve that one can generally at least open and read these unindividual websites. Lanier is concerned that making use of imperfect software will change your humanity to adapt to the software instead the other way round. I can't but have the impression that this concern is borne out of observing a specific community of people rather than the average person. In any case, the scientist in me hears the rethoric and waits for the evidence. Yet, there's no evidence to come in Lanier's book.


Don't people also "reduce themselves" by buying a mass-produced car that comes in one of 5 colors and the only option to customize it is put a sticker on the bumper? The vast majority of people on the planet neither has the interest not the skills nor the money to individualize every detail of their average life. The artist might find that sad, but that's reality.

In any case, the latter point is a crucial one of course. You know that I too have frequently warned about the side-effects that the now common way of financing online presentations via adverts has. People often claim the internet is democratic, then they claim this sort of financing per adverts is just capitalism in action. As a matter of fact the internet is neither democratic, nor is what you're seeing a sensible capitalistic system, simply because people are not payed for their work. They are instead being paid by accidental clicks on banners that pop up on the screens of visitors who might have been looking for something entirely different to begin with. It's a feedback mechanism that one has no reason to expect to lead to any outcome that's beneficial for our societies.

Again however, Lanier misses the larger context. He puts forward a concrete proposal for how to allow artists to earn from their work better than is the case today, basically some system of micro-payments. That is all well and nice, but only addresses part of the problem. The problem that frankly concerns me much more than whether Lanier's musical friends can make a living is that the present organization erodes one of the most essential foundations of democratic societies: journalism. This issue is only mentioned in Lanier's book in the passing at some point. More generally, it is well-known that some services, especially those that are essential to the foundations of our societies, are better offered as public services than as private services. For what I am concerned, the best solution is probably a mixture. I find it particularly disingenuous that Lanier then claims "the only alternative [to some version of the proposal he is advocating] would be to establish some form of socialism."

Lanier also has a proposal for how to improve our financial systems that I don't feel competent to judge on. I can't but think that again he has missed the relevant point. The problem is not to come up with some proposal for improvement. Everybody I know seems to have some idea for how to improve our financial system. Just that most of them don't get their ideas printed in books. The problem is not coming up with an idea for improvement. No, the problem is that the present political and economic system has no instance for such proposals to be considered and be tested viable for reality and promising for improvement. The problem lies on a much deeper level.

It goes on like this. Lanier is a computer scientist, all right, and he clearly knows his field, but again and again he fails to put his proposals or arguments into the larger context and contrast them with the realities of politics and social dynamics. For example, he bemoans that the programming language LISP has fallen out of favor, though in his opinion it is essential to realize some of the proposals he is making. It strikes me similar to the complaint that we're not all speaking Esperanto.
"Wikipedia, for instance, works on what I call the Oracle illusion, in which knowledge of human authorship of a text is suppressed in order to give the text superhuman validity. Traditional holy books work in precisely the same way and present many of the same problems."

His criticism of the benefits of using the knowledge of large groups, though strongly expressed, remain superficial. In my opinion, he is throwing out the baby with the bathwater by not clearly explaining exactly what he is critical of and why, where the benefits are and what the drawbacks are. It is not very insightful.

To make matters worse, the book is very incoherently written. It is subdivided in 12 Chapters, that contain vaguely related short subsections to various topics. Ironically, since Lanier is outspoken critical of the blogosphere, the whole thing reads more like a collection of blogposts than a book. I am sure that all these little pieces he is offering fit perfectly together in Lanier's intellectually creative mind, but I had a hard time seeing a line of thought. Somewhere he elaborates on a research project he is working on with a friend on the relation between olfactation and language. That's certainly interesting, but I can't avoid having the impression Lanier just wrote down whatever crossed his mind. The book finally ends unexpectedly, without even so much as an attempt at drawing a conclusion or summarizing the argument. There are pretty much no references in the book to back up his claims or to at least justify his concerns.

That is not to say though that the book is uninteresting. See, having spent the money to buy and the time to read it, I am inclined to find something of value in it now. Lanier touches on many important points, and I hope that the book makes people think. However, exactly because I think that the theme of Lanier's book is important, it is even more disappointing it is so badly argued.

Tuesday, August 17, 2010


At first sight, physicists seem like normal people. But ask what keeps them up at night and you realize the magnitude of their outworldliness. Fellow blogger Steinn for example is kept up by the question whether there is any system of globular clusters which actually traces the underlying stellar light across the underlying galaxy. Richard Easther from Yale, in his FQXi essay, can't sleep because he wonders whether our visible universe is just one pocket in the multiverse. Lee Smolin lists in his book "The Trouble with Physics" the five questions "that keep theoretical physicists up at night," and Perimeter Institute's recent Quantum to Cosmos Festival dedicated a whole discussion session to physicists' insomnia, informing us that, for example David Tong, from Cambridge University, loses sleep over the question how will we ever know if string theory is correct.

What keeps me up at night is the question whether mankind will be able to solve all the problems it is causing, and do so in a timely manner. The question whether, from here on, the suffering on Earth will increase and progress will turn into regress, or whether we will manage to find a sustainable balance. I am wondering how to stabilize our economies, and how to complement them with desperately needed global political institutions.

What keeps me up at night is the question whether the gap between the rich and the poor will ever close, how to ameliorate hunger and disease, war and corruption. Whether climate change will increase the pressure on our political, social, and economic systems so much we'll be tumbling back into the middle ages and our children will speak with awe of the times when everybody had an iPod.

What keeps me up are stories about families losing savings for their children's college education as a consequence of our lacking understanding of the financial systems, stories about people fixing their teeth with glue because they're not able to afford health insurance, and food crisis caused by our inability or unwillingness to comprehend the responsibility a global economy brings. What keeps me up are articles claiming that "a truly free market would enable us to find superior substitutes long before we run out [of oil]," as if anybody could reliably predict successes of creativity and innovation. What keeps me up are people still believing and trusting in the wisdom of some invisible hand, unwilling to realize that there's nobody watching over us and past success is no predictor of future success, unable to learn and to adapt to change they're causing themselves, a species believing itself superior to natural selection, blind to its own stupidity.

When I follow these thoughts, I always end up at the same point, at the question whether humans will ever be able to organize their collective actions smartly enough to manage the effects their presence has on this planet, if we are able to make intelligent enough decisions in a world in which events are getting closer connected every day, or if some brainless slime mould will remain ahead of us. I worry if we will ever be able to make this step or if progress will stop here and now, forever being limited by our inability to grasp the dynamics of global social systems.

What keeps me up at night is the question what I can do to help alleviate unnecessary suffering. Not much ever comes to mind - What is a PhD in physics really good for? - except possibly write about it, talk about it. If you open a newspaper, look beyond the stories. Everybody has an opinion on everything and you'll disagree with many of them, but that's not the relevant layer to look at. What's relevant is that it doesn't matter what all these opinions are, as long as there's no way to intelligently use them. It's all talk and no action. It's all well-meant, but no outcome. It's all rhetorics, but no conclusion. It's all, still, trial and error till one day we'll make an error we won't be able to fix.

That's what keeps me up at night. And then there's Stefan's snoring.

What I do in these sleepless moments is to focus on the problems that I understand well. Why is the cosmological constant so small, yet nonzero? Does the universe have the same laws of nature everywhere? What is space and time? Questions to which I'm sure there is an answer, and though I'm unlikely to find one, nobody will die and nobody will suffer if I wake up in the morning and still don't know why the neutrino masses are so small.

And next time we'll talk about these questions that let me sleep at night.

Saturday, August 14, 2010

More recent distractions

This Charming Man
By Marian Keyes

Is an entertaining book about four women who each have their problem with the same charming man. The plots isn't particularly plausible, but certainly not boring. The book however suffers from an overdose of drama and parallel storylines - it combines everything from quitting smoking over domestic violence, cross-dressing and cancer to alcoholism. Not to forget the obligatory love-stories. Keyes is one of these authors that I guess have an almost exclusively female readership.

Black Swan Rising
By Lee Carroll

A mediocre fantasy-story about a women fighting the return of the evil. Involves a collection of fantasy creatures including a dragon and a vampire, as well as demons possessing humans, creatures made of fog or water, and lots of mysterious spells and objects. Upon closer inspection the "author" of the book turns out to be a pseudonym for a husband-wife team, which maybe explains why I found the writing style somewhat clumsy. It's an averagely written book with an average plot. It's not even bad, I just had the impression I've read it a dozen times already.

The Ice Cream Girls
By Dorothy Koomson

A well-written and well-told story about two girls who in their teenage years were charged for murdering one of their teachers. The story is told when they are in their mid 30s, at which time one of them is being released from prison while the other one is fighting psychological problems and trying to save her marriage. This line of the story is interrupted with the events back when they were teenagers. The characters are well-developed and the plot is interesting. Only shortcoming is that the ending is entirely obvious all the time, simply due to lack of characters introduced.

The Time Traveler's Wife
By Audrey Niffenegger

A lovely, yet incredibly sad story about a man who involuntarily jumps through time. It is written partially from his point of view and partly from his wife's. It is the one and only time-travel story that I can recall having read that stayed truthful to its own logic. I didn't see the movie, but the book is well-written and definitely worth reading.

Thanks For the Memories
By Cecelia Ahern

Is an incredibly dumb, annoying and foreseeable story about a women who receives somebody else's memories with a blood transfusion. Obviously the guy whose memories she now has is nice, good-looking and single. Guess what happens. Don't waste your money on that.

Thursday, August 12, 2010

Technology in Higher Education?

Just came across these results from the annual Faculty Survey of Student Engagement as reported in the THE article "Students 'let down' by the academic Luddites." (Who makes up these titles?) The survey is web-based, conducted in the USA, and usually involves of the order 10,000 faculty members at 50 institutions or so. The shocking result: 84 % of faculty members say they don't use blogs and 3% don't even know what it is.

(In contrast to the THE article, the figure caption says they don't only not use blogs, but have never seen one. I have a hard time believing 84% have never seen a video game either, so I guess the caption is wrong. The only way you cannot ever have seen a blog in the year 2010 is if you don't use the internet altogether.)

I think the main reason that still few people in academia make use of the opportunities new technologies offer is that they simply don't know what it's good for, or don't know how to use them, or both.

Tuesday, August 10, 2010

An update on the status of DSR

Some months back, I summarized for you a paper that I wrote last year about a model called "Deformed Special Relativity" (DSR) with an energy-dependent yet observer-independent speed of light. In my paper, I essentially constructed a scenario that allows one to conclude these models are in conflict with observations to very high precision. Since then, several of you have been asking what happened after that, so here's a brief update.

A short version of my paper was published in PRL, and was mentioned in Science. As you can guess, this made some people quite unhappy. After all, the version of DSR I argued to be ruled out to high precision due to incompatibility with well-confirmed physics of the standard model is the one that's been claimed for a decade to allow a first glimpse on quantum gravitational effects. Frankly, I'm not even happy myself the model doesn't work because I'd very much prefer would we be able to observe something and connect our research to experiment.

Since my paper was published, Giovanni Amelio-Camelia and Lee Smolin, who have both worked on DSR, put out a few papers attempting to find a flaw in my argument. You find these papers here, here and here. My replies to these papers are also on the arxiv, you find them here, here and, the most recent one from today, here. In a nutshell, Amelino-Camelia et al's argument is just wrong due to a mistake in the re-calculation of the constraint. Smolin's two papers are more interesting in that he's doing the smart thing: trying to find an assumption I've made that can be replaced or shown to be not fulfilled to find a way DSR might work. One has to give it to him, he is actually amazingly creative. So far however, neither of his arguments has worked, though they gave me something to think about I hadn't considered in my original paper. Note also that Smolin has meanwhile updated his paper from April, while I haven't come around to update my reply yet, so don't get confused.

In any case, I'm afraid this won't be the end of the story. I'm admittedly quite tired of the whole issue since I have nothing really to win here. I'm either wrong, then I'm wrong, or I'm right, then I'm wasting my time arguing about a model that's wrong. Anyway, if you have any questions about this discussion, that's the place to ask.

Friday, August 06, 2010


    "Look at all these rumors surroundin' me every day
    I just need some time, some time to get away
    From all these rumors, I can't take it no more"

A month ago, Tommaso Dorigo wrote a blogpost Rumors about a light Higgs. I usually just ignore such blogposts. That day, I was in a particularly foul mood and bothered to leave a comment that expressed very clearly my disapproval of such rumor spreading. (You'll find it in the comment section to Tommaso's post, I'm the "not verified B".)

In his post, Tommaso puts forward the opinion that rumors are a handy tool to make science more interesting. I think he's in the first line trying to make himself more interesting. In any case, the topic stayed on my mind. Last week, Dennis Overbye from the NYT wrote a nice essay on rumors in astrophysics that spread at light speed:
"One culprit here is the Web, which was invented to foster better communication among physicists in the first place, but has proved equally adept at spreading disinformation. But another, it seems to me, is the desire for some fundamental discovery about the nature of the universe — the yearning to wake up in a new world — and a growing feeling among astronomers and physicists that we are in fact creeping up on enormous changes with the advent of things like the Large Hadron Collider outside Geneva and the Kepler spacecraft."

The first physics rumor that I can recall hearing of was the discovery of the top quark. It is also one of the very few rumors I've heard that later actually got confirmed. It's not that I don't hear rumors about some alleged signal in some experiment. I certainly find this interesting and thought-stimulating. I think it's quite natural that one talks about this with colleagues, and discusses the probability of it being confirmed and wonders about the implications. But I don't publicly distribute these stories. Nowadays, sooner or later, I'll find that rumor on some blog and then possibly even in a newspaper. Sometimes, by the time I read about it, I already know the rumor wasn't confirmed.

Well, Tommaso's rumor wasn't confirmed either. But the question that stayed with me is whether rumors constitute a valid vehicle to get science across. I don't think so for the following reasons.

First problem is that while it might draw interest in the short run, it erodes trust as well as interest in the long run. Science lives from accuracy more than any other field. The more often people read claims that something maybe was discovered, but then it wasn't, the less attention they'll pay if they read it again. Quantum gravity in cosmic rays! No wait, nothing to find there. Quantum gravity in gravitational wave interferometers! No wait, nothing to find there. Quantum gravity at the LHC. Well, let's see how that goes.

Second problem is one of principle. If rumors are considered a useful tool to draw attention, why not make up a few? It's easy enough, isn't it? Last week for example, I talked to a friend who was just visiting CERN. He doesn't want his name mentioned, but he told me...

Third problem is that these rumors tend to circle around a few presently particularly popular topics or institutions, and if they dominate the news the vast majority of topics remains uncovered. Let's face it, most people on this planet still have no clue how a laser works and are confused by something called the particle-wave-duality. Their understanding of physics is stuck in the middle of the last century, if not some centuries earlier. There's plenty of physics that needs to be brought across more urgently than the latest rumor about dark matter detection. Yes, you might think that's dull. But you think it's dull because you're being fed constantly with the highly speculative, allegedly groundbreaking, maybe-discoveries. I myself would sometimes rather read a useful, popular, introduction about a not-quite-as-hot topic in a field I don't work on rather than quotations about the latest controversy.

Last month, when I saw the July issue of Scientific American on Stefan's doorstep, I was thinking "Oh, no." The headline read "Is the Universe Leaking Energy?" I was thinking, they probably picked some way-out random paper from the arXiv and are trying to proclaim that there's something fishy with energy conservation in General Relativity. Einstein was wrong! Stefan later said, he had exactly the same thought when he saw the headline. Reading the article however, I was pleasantly surprised: Tamara Davis has provided a well-written, insightful and entertaining explanation of, yes, just standard physics knowledge! She writes about symmetries and Noether's laws, conserved quantities, and about time-dependent backgrounds. She explains why there is no conflict between the seeming violation of energy and and accepted physical laws. It's textbook knowledge, yet it made it the title story. That's the sort of articles that we need more of.

Monday, August 02, 2010

Collective Intelligence

On a recent flight I was reading Jaron Lanier's book You Are Not a Gadget: A Manifesto. I got stuck somewhere in the middle and then dozed off watching Avatar. (Brilliant. Best movie I've seen for a long time, even on a tiny in-seat monitor.) This combination got me thinking about a common theme in both: collective intelligence. Lanier is a skeptic. He writes
“The intentions of the cybernetic totalist tribe are good. They are simply following a path that was blazed in earlier times by well-meaning Freudian and Marxists [...] A self-proclaimed materialist movement that attempts to base itself on science starts to look like a religion rather quickly [...] The Singularity and the noospehre, the idea that a collective consciousness emerges from all the users on the web, echo Marxist social determinism and Freud's calculus of perversion.”
And later, in a section “Why It Matters,” he writes “Emphasizing the crowd means deemphasizing individual humans in the design of the society.”

I am very sympathetic to many points Lanier is making, but I dislike the “Manifesto”-style in which he's trying to lead his arguments. In any case, should I make it to the end of his book, I'll write a review. For now however, I want to focus on the topic of collective intelligence, for despite all the words Lanier is quite fuzzy on the use of terminology. I started wondering: What do people actually mean when they talk about collective intelligence? Are they really all talking about the same thing? I came to the conclusion that there's two different notions of collective intelligence, and I thought I'd amuse you with writing about a topic that I know pretty much nothing about.

Setting the Stage

First, let us be clear on what we're talking about: A collective or a group or a crowd will in the following simply be a set with elements. The elements of that set operate on input and create output. I will refer to the input and output likewise as “knowledge.”

I further do not actually want to talk about the “intelligence” of a collective in the common sense for two reasons. One is that a collective can be intelligent one day and stupid the next day. I'd rather focus on one particular process the collective makes instead of assigning a qualifier to it as a whole. A process could be a decision as well as a direct action. Second reason is that using the term intelligent isn't useful without defining it. Thus, I would instead like to talk about collective processes that are beneficial for the collective. That's basically because I don't think measures like the IQ are particularly meaningful to assess intelligence since they also test for knowledge. Sure, the both are in humans correlated with each other because both draw upon the functionality of the same brain, but in principle it's different things: The one, knowledge, is the input a system has to work with, the other one, intelligence, is the procedure by which the input is processed. Clearly, to make good decisions both is needed. That's true for individuals as much as for groups. Consequently, to make beneficial decisions the collective needs to be well-informed as well as have a good way to process that information. Googeling doesn't make you more intelligent. It gives you more information.

Thus, what I will mean in the following with “collective intelligence” is the ability of a set of elements operating on some input to perform processes that are beneficial for the collective. Note that you'll have to define what your set is before you can make any statements. I know, it sounds pretty abstract, but it will be useful in its generality for the following.

Collective Intelligence Type I

The first sort of collective intelligence is simply the gain in knowledge that you can get when you bring many elements of your set together. If every element brings some knowledge, you've now trivially more knowledge together. But that isn't the interesting aspect. The interesting aspect is that you can give the elements of your set the possibility to operate on each other's output, which means that you can create more knowledge than you could have done had they be disconnected.

There's many examples for this sort of collective knowledge. It's what you count on if you bring smart people together and let them talk to each other. They'll exchange ideas, they will build on each others' conclusions, and that way they can produce something genuinely new, say, a groundbreaking paper. I'll count that as a process that's beneficial for the collective. (A recent meeting of this sort is this one, report unfortunately in German.) It is this sort of collective intelligence that has become vastly easier to make use of with the internet, web2.0 and other advances of information technology. It is much easier today than it was two decades ago to give people with shared interests a platform to exchange their ideas.

Note that I carefully wrote that you can get a gain of knowledge by better connectivity. It is however not a given. Just providing a possibility to share knowledge is not necessarily a way to arrive at a good decision, conclusion, or even useful creation of knowledge. Under certain circumstances, too much sharing of knowledge actually dumbs down a group because it reduces heterogeneity. Besides, human cognitive processes are messy and affected by all sorts of biases. As a consequence, the benefit of sharing knowledge depends on how the knowledge is shared, for example because judgement about the truth-value of a piece of knowledge is often dependent on the source it came from. These are some pitfalls that Surowiecki pointed out in his book The Wisdom of Crowds (read my review here). To exploit the additional knowledge gain you get from connecting groups of people you thus have to do some research about the effects and side-effects of social interactions.

You, and you, and you and I, we are some sort of collective and we exchange knowledge. If you give me a piece of information that's useful for my work or if you learn something from me, it's beneficial and I would argue we're thus part of an collective intelligence in that sense. Clearly, the internet has opened a vast potential for this. There's all sorts of unused possibilities in connecting billions of people online which we have only begin to explore. However promising, this sort of collective intelligence is at the same time of a very trivial sort. We're not actually doing anything new here. People have talked to each other and exchanged ideas as long as humans have wondered how to best skin a bear. The difference is just that now we're connecting more people faster and easier.

A mathematical example for this sort of collective intelligence is a group with some basis elements and operators acting on them to create the full group. The basis elements are in this case the knowledge you start with. The operators are the collective. If you only allow each operator to repeatedly act on the same element (his own “knowledge”) you'll generate only a small part of what you'll generate if you allow all operators to act on all elements (use all knowledge).

Collective Intelligence Type II

The first type of collective intelligence is common and readily found in human groups, but in my opinion actually not the interesting type. The interesting type of collective intelligence is one in which knowledge is created by the collective as a whole and not by any of its elements. An example for that is your brain. Your brain is some sort of collective. It consists of neurons that process input and create output. Yet the thought processes that allow you to make conclusions are circuits in your brain that are not assigned to any specific neuron. The steps of your decision can not be broken down to processes on the elements simply because they don't exist on that level. Your intelligence is a truly emergent feature. It doesn't make sense on the level of a neutron.

Note how very different this is to the first example of bringing together elements that create knowledge individually. The first type of collective intelligence is very common among human groups, the latter isn't. Wikipedia is an example of the first sort of (trivial) collective intelligence: It thrives from adding up the knowledge of many individuals. It doesn't actually collectively create anything truly new. The same is the case for crowdsourcing: Posing a problem to a large group of people allows you to use all their knowledge as well as their intelligence. Yet you're not creating anything that wasn't previously there already.

A simple example of actual collective intelligence of type II is the starting point of Surowiecki's book. Have a group of people estimate something like the number of marbles in a jar or the weigh of an ox or something like that. Then take the average value. It will generally give a pretty good result, basically because individual errors average out. (This is an example that does not work well if you allow people to exchange their guesses in advance, it will skew the result. Recall above cautionary note about how to exploit collective wisdom.) What's new here is that one has added a process that was not previously there, a procedure to aggregate individual knowledge other than just adding it up. Note here that it's relevant to first define what you mean with the collective you're talking about before you decide what sort of intelligence you're dealing with. You could easily enough add Bob to your ox-estimating group and what Bob does is that he asks everybody for their guess and takes the average value. Now who is intelligent: Bob or the group? It would depend on whether you did count Bob with his input processing as being part of the group originally, so one has to be precise. Anyway, in this simple case one is just taking an average value, not a very sophisticated aggregation of knowledge, but there are less trivial cases.

For example our economic system, according to the standard general equilibrium theory, the well-known interplay of supply and demand that, ideally, results in pricing products in such a way that the economy runs maximally efficient. The equilibrium that one works towards is not something known by anybody participating in that system. The aggregation mechanism is a free market economy. Now one can debate how well that actually works and under which circumstances the model doesn't apply, but that's not really the point here. The point is that this “invisible hand” of optimization is a features that adds something truly new, some intelligence that is not present on the individual level.

Other examples for human collectives are arguably political decision making processes. Again, one can debate how well these work and how beneficial the outcome really is, more research is clearly needed, but it suffices to say here that at least they work better than nothing at all. The thing is however that for human collectives you need some mechanism to bring back the insight gained from the aggregate to the individual level, either by communicating the result of a decision or directly by converting it into an action or recommendation. Just leaving it standing inaccessibly at the aggregate level isn't useful because actions are still made by the individuals.

I want to add another example of human collectives here which is the academic system. In the academic system we do not have written down rules to aggregate knowledge, neither do we have a model for how it works. However, if you look at the history of science, we nevertheless de facto have some aggregation mechanism. It's not like there was ever a vote whether or not Coulomb's (wrong) magnetic field law should be kept in the textbooks, yet here we are without it. I think Smolin in his book The Trouble with Physics (read my review here) summarized it well:
“Science has succeeded because scientists comprise a community that is defined and maintained by adherence to a shared ethics.”

The shared ethics Smolin is talking about is basically some sort of scientific method. Again one can debate whether Smolin's suggestion is the best way to set up the system, but that isn't the point here. He's right in that, written law or not, scientists have used some sort of ethics and that's what made the scientific community more than just a bunch of smart people. It has created a solid and growing body of knowledge that spreads though educational systems and is the driver of innovation. Note however that this sort of collective intelligence does not create a theory, it (ideally) merely singles out the ones to be kept.

Another example for this sort of collective intelligence outside the human realm is the DNA of the bacterium Escherichia Coli containing information in its topology and not only in its sequence. That's not some “knowledge” that any of the elements of the DNA string encodes - it can only be read off from the whole string. An example of the mathematical sort might be a manifold. Consider every point of the manifold the knowledge and parallel transport by some infinitesimal step the elements of your collective. If you only look at the local surrounding you'll never figure out additional information in the topology of the whole thing. You'll have to do something more for that, like looking for closed loops.


Clearly for me as a scientist the interesting question is what can collective intelligence do for scientific progress. I think we're doing well with the first type of collective intelligence. It is frequently used. The second type of intelligence is however one that does not exist for the creation of scientific knowledge and I am not sure it ever will.

What would it mean, this collective intelligence of type 2 in science? Consider a large group of scientists, maybe thousands, working on a notoriously difficult problem, possibly for decades. They'll collect and publish many pieces of knowledge. Collective intelligence of type 2 would be an aggregation process not working on the individual level that finds a solution to this difficult problem from the pieces scientists have found. However, the aggregation process that commonly worked for this is an individual finding the right pieces and being able to draw the right conclusions, thus type 1 of collective intelligence. Remember what I said earlier, as long as our society is run by the actions of individuals you need some way to bring back collective knowledge to the individual level, otherwise it's useless. But what mechanism do we have for that in science other than a scientist?

There are some few cases in which indeed scientific conclusions have been drawn by aggregation of accumulated knowledge. For example finding relations between seemingly distinct (medical) topics from citation analysis. But these examples are rare and I'm not sure how far one can ever get with this. This then opens the following question: Can it happen that we will not be able to arrive at some insights simply due to the limitations of the human brain to recognize knowledge that is not present at the individual level? And what is the next step of evolution? Can we ever go beyond that?

(Related: See also my post We are Einstein)


I've argued there's two types of collective intelligence: One in which bringing together elements of a group and connecting them creates output that was not possible to create without the connections. In this case however, the output is still created by the single elements, it's just that the connections allow more of it and thus making them can open unused potential. This is the trivial, type 1, sort of collective intelligence. The second, more interesting, sort of collective intelligence one has when the knowledge is not present at the individual level at all. It is contained on the collective level, and its production cannot be assigned to any element of the group in particular.

For what groups of humans are concerned, the first sort of collective intelligence is already well in use and with a better understanding of social dynamics and psychology we will be able to exploit more unused potential. For what the second type is concerned, I think one should rightfully be skeptic. It is questionable how much can be achieved by it, and unclear how it can be created or used. We're a long way from global collective intelligence like that connecting the lifeforms on Pandora.

In his book, Lanier offers the reader a list with suggestions for “what each of us can do” featuring the item “Write a blog post that took weeks of reflection before you heard the inner voice that needed to come out.” Well, I report that I've been reflecting on this for some weeks, though not continuously. After all, I have a job to do. My inner voices are typically busy with some other things than wanting to come out, like reminding me I should put the laundry into the dryer now. In any case, I hope it won't take you several weeks to read it ;-)