All about strings: An interview with Leonard Susskind

Leonard Susskind

Leonard Susskind

Leonard Susskind is considered one of the fathers of string theory in physics. He is the Felix Bloch Professor of Theoretical Physics at Stanford University and Director of the Stanford Institute of Theoretical Physics.This is an edited transcript of an interview with Leonard Susskind (Stanford 13/04/2004)

GZ: What are the big questions in physics today?
LS: The connection between cosmology, gravitation, quantum mechanics and string theory (if it turns out to be the right theory which is probably). For me these are the central questions. Of course there are questions which divide the universe into before year 2000 and after year 2000. There are questions left over from the twentieth century. The questions from the twentieth century are how we understand the pattern of elementary particles and so forth, how we understand what’ s called the Standard Model, how does it fit into something bigger and more complete.
Under 21st century physics I would classify questions that have to do with the structure of universe, as well as the origin of our laws of nature, our laws of physics.

GZ: Could string theory be the “theory of everything” and give all the answers?
LS: I dislike the term “theory of everything” and I would never use it myself and if knew who had said it first I would shoot him. It’s an inflammatory term and all kinds of people correctly say that it is not a theory of everything. It doesn’t explain how the brain works and so it’s a term which I would not use. If it is a theory which can, at some point, explain the origin of the universe and the spectrum of elementary particles and so forth, it remains to be seen. My feeling is that there’s probably only one quantum theory of gravity and string theory appears to be a part of that theory of gravity.
What we are discovering about string theory is very different from what we had expected and hoped for. The original hope of string theory was that it would provide an absolutely unique set of answers to the questions such as: what is the particles’ spectrum, what are the masses of particles. It would have been a very elegant answer, a beautiful mathematical answer and extremely unique. Unique in that we would find that, basically, the world could not be any other way that the way it is. That was the hope. The reality is extremely different. The reality is that the more we study of the theory, the more possible kinds of things we discover it can describe. We discover it’s a theory with a vast number of solutions. We simply find that there are enormous numbers of possible worlds that string theory can describe.

GZ:String theory has often been called a “revolution in physics”…
LS: The word revolution has been tremendously overused. Super and revolution are the most overused words in physics. Everything is a revolution. Is string theory a revolution? We don’t know yet. I think we don’t know what string theory is yet. I think we’ve made very wrong guesses about what string theory will do for us. I think we got it completely wrong. We thought it would give us a unique theory of the elementary particles. Instead it’s giving us perhaps as many as 10500 different possibilities of what the universe could be like. This is very puzzling. What do we make out of it? Do we just randomly pick one of these possible universes? Or all of them are important? What’s going on? My own view for some time now, is that in an inflationary context you could have a patch of this universe, a patch of that, a patch of whatever else is possible. In string theory it looks like 10500 possibilities are possible, each with its own set of particles, set of interactions. My guess is that the universe is just exceedingly big, full of tremendous amount of diversity. All these different possibilities materialize at some place. We simply live where is possible to live, in that part of this giant structure which is not totally hostile or lethal to our existence.

GZ: String theory has captured the public imagination because it refers to hidden dimensions. Of course, science fiction stories have made a lot of hidden dimensions. Why do we need so many extra dimensions to explain nature?
LS: Wish I could give you a simple mathematical explanation, for I’m afraid nobody can explain it simply otherwise. It‘s a very complicated theory which fits together in a consistent way only if the number of dimensions are ten or eleven. Why does physics need them? Elementary particles in the ordinary view of things are point particles. A point can’t have many, many properties. A point is too simple to have properties. However, we know that elementary particles have a lot of properties. They have spin, they have electric charge, they have something called isotopic spin, they have a quantum number called color – it’s not got anything to do with ordinary color – they have generations that they belong to, there are whole catalogs of different kinds of quantum numbers, of different kinds of properties that quarks, electrons, netrinos, or photons have. It sounds unreasonable for a point to have that structure. So the feeling most of us have is that, at some level, if you look deeply enough into things, you‘ll discover that particles aren’t points. That they must have all kinds of internal machinery that gives them these properties. One of those machineries, one of the ingredients into understanding what the quantum numbers of particles are, is the idea of higher dimensions. I‘ll give you an example. The simplest and oldest theory of higher dimensions is called the Kaluza theory. It was invented by Kaluza in 1917. Einstein liked it very much. It postulated one extra dimension, i.e. a particle in the extra dimension could be regarded as a little circular dimension. The idea of Kaluza theory is that the particle can move not only in the usual three directions of space but it can also move around in this extra dimension. Well, the particle which moves around in the extra dimension is different than one that moves differently in the extra dimension. The amount of speed that is going in the extra dimension as well as the direction it goes matter a lot. What is this new option corresponds to? It corresponds to the electric charge of the particle in Kaluza’s theory. So, electric charge becomes motion in another direction, in a new direction. What’s going on now is that these extra directions – all of them – correspond in various kinds of ways to the extra properties that these points have. So I wouldn’t say that we needed the extra dimensions, but we needed the kind of structure, the kind of complexity in space that could explain why these other degrees of freedom are there.

GZ: Skeptics say that string theory will forever remain outside the realm of real science, because it’s not experimentally falsifiable.

LS: I would simply dismiss these people for lack of imagination. There are all these people who are constantly pontificating of what science is and what science isn’t. These people lack of imagination. I also lack of imagination but I have a lot of imagination to know that I lack of imagination. We do not know what people can do in the future. We do not know what the human intelligence is capable of collectively. True, we are in a new course of exploration s studying extremely remote things which are very, very difficult to establish experimentally. But we should not abandon our course.GZ: Let me take you back to what we discussed before about string theory predicting up to 10500 different possible universes. Is this perhaps an answer to the paradox that we live in a universe so finely-tuned. Is this the answer to the Anthropic principle?
LS: That may be. My view is that the fine-tuning of the universe, particularly with regards to the cosmological constant, is so exceptional that we can no longer ignore it. Nevertheless, we have to ask whether the Anthropic principle is really serious business. Different people mean different things by the anthropic principle. Some give a religious depth to that thing, that the Almighty created the universe for no other purpose than people to live there. That’s one theory to which I don’t subscribe. I think it’s the duty of physicists and scientists to take that theory only as an absolutely last resort, when everything else fails. Other people think it’s part of the weirdness of quantum mechanics that somehow we live in the one place we can.
My view is a little different. It’s similar to asking why we live on a planet which is so finely-tuned. Our planet is at just the right distance from the sun so that we do not get boiled or frozen. That’s a very small window of opportunity, it’s a fine tuning. To find the reason why this is so, you need at least two things: a set of very large alternative possibilities and a cosmology which creates all of these different possibilities. So, it wouldn’t be enough to know that the “planet equation” – whatever it is – has many, many solutions with different values of, say, the “right temperature”. I also want to know that the surrounding universe grew and expanded creating lots of planets. Those two ingredients make sense out of this anthropic idea. One, that the theory, whatever it is, has so many solutions that even though it takes a very fine tuning for life, there will still be enough other solutions, so that statistically there will be one. And that, whatever the cosmology of the universe is, it creates always different possibilities some place.GZ: How about string theory then. Does it fit your two requirements for an explanation?
LS: I think that string theory provides us with a space of enormous possibilities. By involving so many mechanisms put together in various combinations the number of possible universe is 10500or something. We don’t what the number is, but it’s vast. The other thing we need is something like Linde’s and Lincoln’s theory of eternal inflation, where inflation takes place constantly and spins off different environments. Their ideas seem to me to be very, very reasonable, that the universe expands to something enormously big and it creates patches of all different kinds of what Alan Guth calls “pocket-universes”.GZ: Could we ever find if that is true?
LS: For the moment it looks impossible because of the horizon problem. Our world has a horizon that we can not see beyond. Presumably these other worlds are behind this horizon. One of the things we’ve learnt from thinking about black holes in the context of string theory, is that at quantum level the horizon is not really a barrier to knowledge. What goes on outside the horizon is also equally well described by the Hawking radiation of the black hole. I suspect that cosmic horizons are scrambled in complicated ways. Cosmic microwave background, which is light Hawking radiation, has this information in it. Can anybody ever extracted it? Certainly not with experimental tools currently available. But as I said never say never. We don’t know what the limits of imagination, or the limits of intelligence, are and that’s something for the future to do. Young smart physicists want to be explorers. They want to explore those things which everybody else says are impossible.GZ: The LHC is underway and will soon start experiments for the Higgs particle . Will they find it?
LS: I think so. I don’t see any other good alternative.

GZ: So the LHC is money worth spent!
LS: Well, yes, whether we find the Higg’s particle or not. If we find it’s there, that’s wonderful and confirms everything we knew. If it’s not there, it’s even more radical and money will have been even better spent. It will mean that we have been thinking wrong about physics for thirty years now.

GZ: Is time is an illusion?
LS:Space is an illusion. You are an illusion.

GZ:This sounds very Buddhist to me.
LS:Well, physicists don’t think that way because it’s not a useful way to think. We can measure time, just like as we can measure space, just like we can measure electrons. So why pick on time as being an illusion? Everything is an illusion in that view. But it’s not a useful view for a physicist. If you can measure it, if you can describe it, then we regard it as real.

GZ: Let me press this point of illusion a little further. Quantum mechanics introduces the observer into the very fabric in reality. Somehow if you take observers out, if you take consciousness out, “reality” ceases to exist. Does the universe exist when we do not observe it?
LS: I’m not a philosopher and I’m trying not to be philosophical. I’m trying to be more practical. Let’s see…Ask me the question again.

GZ: Is there something that we can call extended reality, a reality outside our perception? Or are we constantly creating reality through our measurements or our observations?
LS: We don’t really know how to understand the world of quantum mechanics. We know how to understand one special set of circumstances, where you can clearly separate the world in observer and system.
But the real world is not like that. We the observers are always part of the system. In the context of the laboratory we can usually make some separations. We cannot make that separation about cosmology of the universe. We are part of it. We influence it. So we do not really understand how to think about a system when we are a part of it, because of quantum mechanics. A very good friend goes so far as to say that he doesn’t think that quantum mechanics is complete because of this. And he thinks underlying the quantum mechanics is something much more deterministic. Most physicists think it’s a screwy idea. My answer is I don’t know.

GZ: When we talk about physics, when we talk about reality, we usually talk about energy, talk about matter, interactions between particles and fields etc. Let me for a moment suggest to you that the universe is not like that at all, the universe is made out of bits and information. Wolfram wrote a book about cellular automata which made quite of sensation. Could you believe in Matrix world? Could the universe be made out of bits, at an elementary level?
LS: Yes I think that it is made out of bits. It is nothing but information .

GZ: Could this notion change our physics?
LS: No, it can explain our physics. With respect to Wolfram, I’ m a physicist who thinks Wolfram’s ideas are interesting. But keep in mind that Wolfram’s ideas have no place for quantum mechanics. And the world is quantum mechanical. Wolfram believes that the world is cellular automata. But he knows that cellular automata are not quantum mechanical. Quantum mechanics has to come from somewhere. Where does it come from I don’t know. So I would say, until you can understand why the world is quantum mechanical, to say that it’s made of cellular automata is servicing a point. No quantum mechanics no cigar.

GZ: Einstein once said that the most inexplicable thing about this universe is that we can explain it. Are we now reaching the limits of our cognitive abilities? Do you believe that there are cognitive limitations to the human mind?
LS: Sure there are limitations. The human mind can not have more bits of information than the whole universe has. There are limitations to the human abilities in general. I would have bet anything on that no human being can play six musical instruments at the same time. I would have bet very much that nobody can jump as high as Michael Jordan. It turns out that the ranges of people have in the very, very far parts of the distribution are so amazing that nobody would have guess that they were possible. When people say such things as we’re reaching the limits, what they really mean is that I ´m reaching my limit. When they say they can’t conceive of anybody solving a certain problem what they really mean is that they can conceive of themselves solving this problem. The limits are probably way beyond what we imagine. They always are. The danger in trying to predict the limits of human abilities is always going in the wrong direction. It’s much more likely to underestimate than to overestimate. As long as it’s physically possible, as long as it doesn’t violate the laws of nature, it means there’s a possibility that human beings can do it. Forget individuals. Collectively human beings have such a diversity of different kinds or ways of thinking, they have the flexibility to be able to bend their own way of thinking about new things. We simply don’t know, but I would guess that when we try to estimate these things we ‘re in much more danger of underestimating to what people can do than overestimate it.

GZ: As we expand our knowledge of the cosmos through our physics, if we ever reach points that we don’t really understand and we can not possibly falsify, then are we in a danger that science, physics can regresses to religion?
LS: There is such a danger. So, on one hand there is such a danger and in the other hand I also say that you are also in danger of underestimating what people will be able to do in the future. Will they be able to do experiments that now seem to be so completely out of this world that they seem totally impossible? I‘ll give you two examples. The first is the inflationary theory of the universe. Everybody who saw that the first time said “well, that’s very nice Alan Guth, but your own admission of the inflation of the universe wipes out any evidence of itself. Nobody will ever be able to make science out of it”. That’s what everybody said, including Alan. Nobody expected that within twenty-five years people would figure out how to confirm observationally that the inflation theory was right. But it happened. I’ll give you another example. I can easily imagine people telling Darwin “nice theory Charles, but the only way to confirm it will be to go back a billion years and see what’s going on, and that’s simply impossible”. Well, it took a hundred years to make science out of evolutionary theory. It took a hundred years for people to get enough knowledge about biochemistry and genetics, to watch microorganisms evolve. It took a hundred years but it happened. And as I said the two dangers are, falling into a trap of t faith-based physics, but also giving up because it looks too hard.

GZ: Apart from technological development making life more comfortable what is the role of science in the 21st century? With regards to politics, society and perhaps ideologically. Does science play a role in modern world of religious conflict, fanaticism and lack of rationality?
LS: To a certain extent I think physicists have been the keepers of the truth. A case of point would be the Soviet Union during the dark days when the keepers of the truth were physicists, people like Zakharof and Orlof. They were people who simply believed in the concept of the truth. You know what’s happened to the concept of the truth in American society? It’s been replaced by advertising! All kinds of things which tend to make irrelevant to what’s true and what’s not true. Scientists in general are people who recognize what it means for something to be true. They are people who will question when something it’s not true. And their whole mental make up, their whole ideological basis, has to do with finding the truth. That’s necessary for preserving society.

GZ: So you are not a postmodernist?

LS: Postmodernism has some truth but it has been carried too far. It is true that the way humans think about the laws of nature, the words that we use to explain things, are dependent on culture and so forth. When new scientific ideas come into the front a lot of the argument about them tends to be dominated about the language that we should use to describe them. But, eventually, through some filter, what comes out of the other end is pretty much independent of the specific mentalities of the people who discovered it. And so yes, I believe there is real truth in the bottom of all of it, and it’s also true that the language we use to describe things depends on culture. So, that was a good idea, it was an important idea but it got carried too far when it said that there’s no such thing as objective truth.

What banged?

Until recently scientists and priests seemed to be in awkward agreement. Genesis started with a bang! It happened 13.7 billion years ago; and questions like “what caused it?” or “what was there before?” were considered a scientific no-man’s land where no decent, career-minding, physicist dared to venture. After all science is about things that can be measured. How could one measure something before it happened?

This was precisely the subject of the public lecture given by Cambridge physicist Neil Turok on April 17th at the Athens Concert Hall. The daring title was “what banged?” and it aimed to introduce a radical new cosmological theory. Turok, together with Paul Steinhardt of Princeton, have named their theory “the ekpyrotic universe” and explain it in their trade book “Endless Universe” (published in Greece by Avgo Books, According to the pair of authors, there have been countless Big Bangs, followed by long terms of space-time expansion, an endless cycle of universal birth and re-birth. “Only by positing an endless universe can we explain the mysteries of the cosmos,” said Turok like a modern-day Brahman.

Cosmic Puzzles
And there are mysteries aplenty to keep cosmologists on their toes. Following the observational confirmation of the Big Bang theory in 1964 by Penzias and Wilson, scientists had to explain how the universe was so uniform (same average density of matter and energy wherever you chose to turn your telescope). They thus hypothesized something that happened during the first critical moments of the Big Bang, a force field that guaranteed thermal equilibrium across the universe as well as uniformity of matter and energy (think of an electric heater trying to heat up uniformly a room that keeps expanding, and you will understand the difficulty cosmologists were facing). The force field was called “inflationary field”.

In summary, the traditional viewpoint holds that a tiny fraction of time after the Big Bang, the Universe expanded with an amazing rate, doubling itself in size every billionth of a billionth of a second. The cause of this incredible expansion – named “inflation” – was first suggested by Alan Guth, now at MIT. Inflation worked on the early universe only for a very short while and then died out, allowing for a much slower expansion afterwards. It was an elegant, albeit ad hoc, hypothesis that seemed to satisfy observation data – until two new observational puzzles arrived to upset it.

The first puzzle is the so-called “dark matter” that accounts for 25% of the cosmos (“normal” matter, the stuff of stars, galaxies, you and me, accounts for only 5%). No one knows what dark matter is, but we do know it is out there, in the same way that we know there is water in a glass even if transparent (light bends when travelling through it). The second weirdness is “dark energy”; it accounts for 70% of the universe, and a few billion years ago started to accelerate the universe’s rate of expansion. The inflationary hypothesis had to be urgently overhauled in order to account for both.

Getting rid of Inflation
Turok and Steinhardt had both worked as theorists on the inflationary model of the Big Bang, but became increasingly disillusioned with its ad hoc character; until they decided to apply the mathematics of string theory to the early universe and see what happens. When they did so all puzzles and weirdness disappeared! No need for an invented inflationary field! Dark matter and dark energy were acounted for and made perfect sense! It was an incredible eureka moment! All you had to hypothesize was that we live in a universe of normal matter that hovers parallel to another universe of dark matter. Between the two parallel universes flows dark energy, pulling and pushing them apart. When the two universes collide a Big Bang occurs; all matter and energy becomes light and a new pair of twin universes is born; the “normal matter universe” expands and cools by pulling away from its “dark matter” twin sister and then, when expansion arrives at its maximum, dark energy pulls the two universes back for another collision – and the whole cycle starts anew.

Ekpyrotic Strings
To understand better the ekpyrotic universe hypothesis you have to understand strings. Since the early 20th century physicists have two wonderful theories to explain everything: the relativity theory of Einstein that deals with gravity and explains natural phenomena from a multi-molecular scale upwards to planets and galaxies and clusters of galaxies – and quantum theory, which explains what happens at a submolecular and subatomic scale. The problem is that scientists cannot reconcile – or “unify” – the two theories together. This is extremely annoying because it suggests that nature is operating different laws at macroscopic and microscopic levels, which is absurd. String theory, rich in exotic mathematics and developed during the past twenty years, comes to the rescue! It suggests that nature is built by tiny, dimensionless strings, objects that look like rubber bands. Depending on the oscillations and twists of those tiny strings, the cosmos behaves in a quantum or relativistic way.

According to string theory our universe can be seen as a three dimensional membrane where space-time is stretched and pulled by dark energy. Think of space-time as the arena and planets and galaxies as the objects inside it. String theory suggests that the sun and Earth spring into existence from within the fundamental geometry of space-time. In other words, everything is the physical realization of mathematical entities. The world is a shadow show of maths-at-work in a multi-dimensional background! Plato, had he been among the audience of Athens Concert Hall that night, would have felt vindicated.

Complexity begets complexity
What I find exceptionally thrilling with string cosmologies such as the Ekpyrotic Universe is that instead of assuming material nothingness as the primal cause of the Universe they presuppose mathematical complexity. Indeed, the mathematical complexity of the vacuum assumed by the ekpyrotic theory – and its parent M theory – is (at least for the time being) enormous, to an extent as yet unimaginable. But we do not need to see the whole mathematical picture in order to appreciate that, the very idea whereby a complex universe – such as the one we inhabit – manifests out of complex mathematical-geometrical entities offers a new and deep insight. Could these complex mathematical-geometrical entities be the natural laws? Could the laws of nature resemble abstract, immaterial casts into which planets, starts and creatures and minds are molded? If that is the true nature of reality, I somehow feel that it makes far more sense than silly ideas such as the Copenhagen Interpenetration, or the Multiple Worlds interpretation of quantum physics.

LISA will test
Turok and Steinhardt applied string mathematics to the early universe and found that the theory works perfectly. But how can they be sure? One must always judge the efficacy of a beautiful scientific idea by the means that can be tested. Can we do so in this case? Surely the only way to tell if the ekpyrotic theory is correct is to peer into the moment of Big Bang itself, to go behind the primal afterglow as sensed by W-MAP. But can we measure anything before radiation was born? According to Turok we can! We can measure gravitational waves, the ripples of cosmic turbulence that travel across space-time, like waves on the surface of a pond when a stone has been tossed. And that is exactly what is going to happen in 2018 when spacecraft LISA (Laser Interferometer Space Antenna), a joint venture of NASA and the European Space Agency, will aim to detect and confirm the existence of gravitational waves. If Turok is right there should be no gravitational waves from the Big Bang.

He certainly believes in his theory, so much that he made a wager with a very famous wager-man who also happens to be Neil’s friend as well as his colleague-down-the-corridor at Cambridge University. “I betted Stephen Hawking I’m right”, he said smiling, to the general applause of the Athenian audience.

(This article commissioned was published in “The Athens News”)

A Wh(ITER) elephant?

Imagine a machine that you can throw in a few grams of hydrogen – which abounds in the Earth’s oceans – crank it a few times, and harvest massive amounts of cheap energy. And all that thanks to fusion, a physical process where the nuclei of two elements (for example deuterium and tritium, which are kinds of hydrogen) fuse together to produce a new element (helium). The new, fused, nucleus is somewhat less than the sum of the two original nuclei, and the residual mass becomes energy (called “thermonuclear”) according to Einstein’s famous formula E=mc2. And that’s all the physics you need to solve Earth’s energy problems!

Fusion sounds too good – and because it is also true – it has led to ITER, the “International Thermonuclear Experimental Reactor”, a 10billion dollar megaproject, jointly funded by the EU, Russia, US, Japan, South Korea, China and India. ITER’s long and turbulent history began in 1985 as a political-cum-scientific gesture towards easing Cold War tensions. The West and the Soviet Union, each one having developed their own thermonuclear technologies, decided to put them together for the benefit of all mankind. The Soviet Union collapsed but ITER survived. After much politicking and dramatic bargaining over the ensuing decades, its location has been finally decided: Cadarache, near Marseille.

ITER will take 10 years to construct, and 20 more years to operate. It will build upon experience gained from previous experiments, such as JET (The “Joint European Taurus”), and will test new ideas and designs for a reactor. Although the science is well-known and straight-forward, the engineering is a daunting task evermore. For nuclear fusion to occur elements have to be stripped off their electrons. This state of “electron-less” matter is called “plasma”. The Sun is a fireball of plasma and its radiant energy is theorized to be the result of naturally occurring fusion. Plasma only exists in extremely high temperatures and therefore no material container can contain it. So engineers must develop something “immaterial”; a magnetic field powerful enough to hold plasma at 100 million degrees centigrade. By 2018 the hope to fuse half a gram of hydrogen, sustain the generated plasma for 400 seconds, and produce 500MW of energy. (By comparison, in 1997 JET managed to sustain plasma for half a second only and produce 16.1MW). Commercial thermonuclear reactors are envisaged by 2050.

The promise of ITER is environmentally benign, widely applicable, essentially inexhaustible electricity. Criticism from environmental groups focuses mainly on safety and waste disposal; however safety is inherent in fusion reactors (if plasma cools, even slightly, reactions stop at once) and the only waste is water. Fusion reactors may become radioactive but much less so than commercial nuclear reactors currently in use; and tested technologies to safely manage decommissioning already exist. Indeed, faced with the huge challenge to drastically cut down on greenhouse emissions, thermonuclear energy seems god-sent. Economic growth, which lifts people out of poverty, increases prosperity and guarantees peace, is based on the assumption of cheap, renewable, and widely available, energy resources. Such resources do not exist on our planet. Solar, wind and hyrdo cannot keep pace with the required rates of economic growth. Thermonuclear, with its zero emissions, inherent safety, minimum waste management overheads, and Mega-watt energy output is seen, by ITER’s supporters, as the only real alternative.

Nevertheless, serious scientific skepticism points to the fact that, although the uranium-fission bomb that obliterated Hiroshima and Nagasaki in 1945 has found peaceful use in nuclear reactors, the hydrogen-fusion bomb of 1952 has not. Containing the plasma at 100 million degrees for any economically meaningful period, may be an impossible engineering feat. Furthermore, the prevailing theory that the Sun is a gigantic fusion reactor is currently in dispute because it does not comply with new measurements of solar radiation. NASA is scheduling missions to investigate alternative explanations for the Sun’s mysterious energy cycle.

Could ITER be a White Elephant? A multi-billion megaproject which will result in nothing but water?

Questions such as these have led the US to vacillate in and out of ITER, and Canada to let go for good. The current political climate does not help either. The reasoning behind any “blue-sky” exploration smacks against the “precautionary principle”, an idea dominating contemporary political discourse. In a risk-averse society, playing with an expensive toy full of radioactive plasma may sound like an abomination. And yet we humans have managed to survive thus far by taking risks, by going out there and hoping to discover something new. Stifling potentially vital innovation on the grounds that it is “very difficult” to produce any results, or that it may incur “risk”, may be a far more dangerous proposition.

This article was commissioned for the Athens News