P. Did he have a broader knowledge, more secure and grounded? R. Yes, I wanted to understand, I wanted to understand nature, not only to use it, and immediately applies engineering knowledge to specific sectors. So I decided to study physics.
P. Mr. Cirac, what is reality for a theoretical physicist? R. The reality is very complicated because it depends on the observer. The truth depends on who observes or looks. Is different, in principle, for a person than another. In fact, reality is not defined until the person lives. It's very different from what people usually think that reality is simply there and one apprehends. For quantum physics is an active observer of reality and who adjust.
P. Investigates how a theoretical physicist? Does it define problems? Does it show so apodictic propositions as in mathematics? Is strongly influenced by the possible applications or research only to expand knowledge? R. Usually the first thing is a theoretical physicist ask questions, how things work, how are the nature and the universe, how is the macroscopic world and microscopic, where it comes from and where does the universe. Then try to ask these questions using a very complicated mathematical apparatus. Thereafter, when questions are concretized, try using one hand to answer math and another observation. Applied physicists do experiments and theoretical physicists interpret them and make predictions that are then tested by experimental physicists or applied. In principle, fundamental research is aimed at the mere extension of knowledge, but admit that finding some shade.
P. Mr. Cirac, forgive the flippancy. I understood the concept infinitesimal limit of a sequence of real numbers experienced a joy hard to define ... R. ... No, not arrogance ...
P. ... I appreciate the comment, Mr. Cirac. As I said, he sensed it was a concept that contained a huge potential. By demonstrating a concept formalized in the s. XIX certain infinite series of real numbers converges to one, could be solved analytically and a very elegant way the famous paradox of Zeno wise. And so rigorous that knowledge I can share with any teenager gifted for mathematics. "Theoretical Physics Experiment with deep joy that can only share with your colleagues? R. Yes, the truth is that yes, we really enjoyed the telling physical things between us. However, when a person who is not engaged in quantum physics asks me what I do, I research, the motivations and possible applications of research, maybe fifty years from now, I have to respond in a way very superficial. And yes, it produces a much welcome the resolve to achieve a complete problem, but this is achieved, as I said before, using a complex mathematical methods, so there is no way that the satisfaction of sharing a person who is not engaged it. For So the answer to your question is yes, the joys experienced quantum physicists are not shareable.
P. So, Mr. Cirac, is best understood with a mathematical or physical Thai with me? R. Well, if I talk to them about quantum physics and mathematics from the field, yes, are Thailand, China or Japan. But ... I could not speak Castilian with them (laughs). So it also depends on who you speak, what I mean, how I speak, where I speak, the conditions under which I speak, when to speak and to speak (more laughter, this time shared).
P. What is more difficult to solve a problem or define it? Because I guess to solve previously be defined. R. Both are difficult. The most important thing is to define the problem usually. There are problems whose solution is relatively simple, others are more complicated and there is also unsolvable, from the statement of Gödel's theorem, we know that there are insurmountable problems that less than a century ago were considered solvable. But undoubtedly the most important in physics, and I think also in mathematics, is posing the problem. Really is and put your finger on the pulse.
P. He mentioned to Kurt Gödel. How is possible that a theorem which gives a hack to pure mathematics and the lower pedestal, is nonetheless a milestone required to explain the extraordinary development of mathematics for most of the s. XX? Has something similar happened with the theory of relativity of Einstein and fundamental physics? R. Yes, it is oversimplifying a bit like you say. Since the contributions of Gödel and the statement of the Heisenberg uncertainty principle, we know that we can not prove or know if something is true or not.
P. What is the total encryption of messages? Should we understand that is absolute in the usual sense we have this word? R. I do not know exactly which meaning is concerned.
P. That is, with full guarantees, that does not fit any errors, ehh ... R. Impregnable.
P. Yes, that is, Mr. Cirac, thanks. R. You can set some premises within these premises and there is absolute security. If a sender attempts to send a message to a receiver and that receiver who should be, you can get absolute security. Let me give you a simple example. Imagine you want to send a secret message using quantum cryptography, or other method, a receiver and that receiver is cheating on him by impersonating other and giving a false ID card number. You think that sends the message to the appropriate receiver, when not, and the recipient gets the message wrong. The remarkable thing about the example that I have exposed is that there are ways to cheat. When we talk about total security, it assumes that the receiver is the real recipient and the sender is the real sender. Under this premise, yes you can get a complete and absolutely secure encryption.
P. If I'm not mistaken, there are already two U.S. companies that have implemented the technique of quantum encryption. R. Well, one is in the U.S. and one in Switzerland. There is also a European project to develop and commercialize of these technologies.
P. Are we talking about more affordable prices or astronomical? R. We talked about numbers around one hundred thousand €. Are prices that can not currently compete in the market with traditional methods of encryption.
P. What time would be speaking for quantum encryption, in all its applications, was technically feasible to any terrestrial distance? R. It is difficult to predict. May be five or twenty years.
P. Is it still true in Spain, the phenomenon of brain drain? R. I think the phenomenon of the brain drain out of focus. The brain drain does not hide in my view no pejorative connotation, but it is good and necessary. It is a phenomenon that occurs everywhere. German scientists are to be U.S., U.S. scientists to be Japanese, English scientists are going off and it would be good to have foreign scientists who come to Spain. Let me explain. The main problem is that a country can not have cutting-edge research in all fields of knowledge, this is impossible, you have to specialize. In the air in which you specialize, you have to strive for the best, regardless of whether they are English or foreign. And that's what happens in the USA, Germany and other countries. There is no fear that English scientists go out, because that is a sign that in Spain there is a good training in basic research and is working properly and seriously.
P. How many fellows do you have now at the Max Planck Munich and how many were English? R. In group I lead is about twenty scientists, ten Ph.D. and make the rest do a post-doctoral, what we call assistants and aides. At the moment I have two PhD students and four English English scientists in post-doctoral stay.
P. More of a quarter. It is a very encouraging for English science, right? R. I do not know if it will be a unique example or not. The truth is that the English are very well trained in theoretical physics. Everyone I have in the Max Planck scientists are very good, really special.
P. I guess that also be because the English public universities that offer degrees in theoretical physics or fundamental are very good. R. I know all the English public universities. In some, the training given in theoretical physics is excellent and is the best in the world, no doubt.
P. What would you say to a young pre-university you are reading this interview, a young, well, explained that curious about natural phenomena that have good skills in abstract reasoning and mathematics, that dude from fundamental physics to study or discipline concrete and immediate? I do not know, maybe because his parents or his girlfriend prefer to be a top engineer. R. I would say go ahead. It is a privilege and a luxury to work on something you like. You probably have to travel a lot and will be difficult to obtain a permanent position working. But with effort and dedication, the ability to work in the field of theoretical research is very real.
P. What about the topic, so prevalent in many environments, the alleged incompatibility between scientific knowledge and transcendental truths and supernatural? R. Well, I think there is a barrier, that is, science can not enter into that world. You can discard a number of things, tweak a little in others, but I think that scientists have no advantage over other people to be able to speak more authoritatively on these issues.
P. That is, in principle means that the process of knowledge are distinct and separate. R. Yes physicist making is to propose and experiment. Experience on the transcendent issues is very difficult, or impossible, at least in the way we do physics.
P. In his opinion, why is so little fruitful dialogue between theoretical physicists and people who grow other disciplines, as philosophers? R. Sometimes there are language barriers. It is difficult to communicate with someone who is not your specialty. Sometimes the questions are the same, or have converged aspects, but to answer sights are different. To give one example, physicists try to answer the question consisting of where we came from and where we go, how life formed and how life will end. And I suppose that philosophers are also trying to find one or more answers to this question. To do this, physicists use a scientific method to propose experimental laws, etc .- and philosophers believe that do not follow a method like ours. In that sense, physicists are very deformed, and as we do not show it with experiments and mathematically, we are not convinced. And I suppose that philosophers are not convinced.
P. I thought surely my ignorance, Mr. Cirac, theoretical physicists occupied a privileged hill to rule on these issues. R. No, do not think so.
P. How important in the work of you the passion for the pursuit of truth? R. It's really important. We feel and experience that passion for the pursuit of truth, but it is objective truth, the truth of what can be experienced. We can not talk about things that can not be experienced.
P. They say that behind every great man is a great woman. What does his wife, his two daughters and his son? R. What can you say a husband of his wife and children? I find it difficult to express in an interview. The word, which does not come out, would indicate a sense very noble and elevated, as you may suppose. They have helped me a lot, especially my wife. I have understood and been able to withstand a lot. Put up all this time, supporting my long stay in the U.S., support the sense of rootlessness that a person suffers when he went to live first Austria and then Germany with little knowledge of German. And my children also, of course.
P. Do you explain his extraordinary career in the field of quantum optics without his marriage to Eva Monteagudo? R. It is difficult to answer. Since then, Eva has helped me, supported and very supportive. Perhaps another woman would not have accepted the sacrifice that involve decisions difficult I had to make in order to continue my research work quantum.
P. What is the first thing I did upon learning of the award of the Prince of Asturias? R. Phone call to my wife. After seven hours I was addressing journalists in many countries, often with both hands, with an earpiece in each ear (smile, Mr. Cirac fluent in several languages \u200b\u200bother than Castilian).
P. What is the value attached to education and culture of the effort in childhood and adolescence? R. The effort is important. In our field, if you dedicate yourself to Physics and research in a serious way, it takes much effort and work. And that also entails sacrifices and privations. You often have to put in the background many personal things that sometimes are very important, like family, and sometimes not so: for example, I would have more time to read about topics that are not my specialty .
P. And have you noticed at some point, Mr. Cirac, that excessive devotion to her sister wrong with having a family? Did his wife has ever complained? The question is in jest, of course (add awkwardly). R. No, the truth is that it is one of the things I have to thank Eva. She never has accused me and was able to understand. Has understood that he married someone who has a peculiar work. But I guess the wife of a fisherman will be the same.
P. Mr. Cirac, is there an imbalance in Western man from his extraordinary intelligence operations and moral heritage? Is easily manipulated? What do you think? R. I made a rather philosophical question that has nothing to do with theoretical physics. I will respond in a personal capacity, not as a quantum physicist. I think yes, it is easily manipulated.
P. What about the imbalance between the high operational and analytical capacity and moral heritage, ie the power to make decisions for yourself in these three or four truly great issues of our existence? I know it's an unusual question, Mr. Cirac, I know it very well could tell me where I was welcomed to speak kindly of his contributions to quantum optics. R. No, no, okay. We'll see. I recognize that the question is interesting but far-reaching. There are currently raised a related issue. It is, as I say, a matter of much depth to which I do not know how to respond and, if I mistake not, scientists either. Is there really free will? Put another way, is there a possibility to decide on people? I put a simple example, schematic, elementary: if atoms together conveniently and these atoms do a liver, heart and brain, can have life?, "" It "could decide?, Is there really" something "that enclose the power to decide, "something" that is independent of itself, and mere physical body? You see, my argument is circular. As I do not know to answer this question because I do not know if it is as I say or not, obviously I can not answer that you raised me.
P. Well, Mr. Cirac, are questions which I believe do not support a physical demonstration. Consciousness, What is for you the human conscience, Mr. Cirac? R. Well, one can think of an experiment. Imagine I put a blank card and a yellow and say that you choose one of the two and noticed that every time I send a signal to the brain more often choose the yellow than white. What would that mean? Maybe it means that the decisions we make are based on physical phenomena, perhaps in areas of active or less active in our brain ...
P. (I've been so reckless that I interrupted Mr. Cirac. Transcribe the dialogue I realized my mistake. Is the first time that I make, the interrupt, it is understood. Moreover, almost from the beginning of the interview I waive scripts and prepared questions. I do not see the slightest bitterness in Mr. Cirac for having interrupted, quite the contrary.) ... This reminds me of Pavlov's experiment (Shall I not been myself a victim of the Pavlov experiment? is the first thing that popped into my mind at that moment in a flash!). I do not deny that we are conditioned by many circumstances when making decisions, even accept part of the theory of the unconscious of Freud in perspective, since I believe that we are often not as aware as we of our own actions. In some scientific circles, perhaps now less, it is postulated behavioral determinism human. Do you believe in human freedom, Mr. Cirac? R. I would tend to say yes, but precisely what I was talking about is conditioning, perhaps not only the total conditioning, determinism, but also partial. Is there a total conditioning or only partial? I would think that is only partial, even I would think that sometimes there is no such conditioning, but as a physicist not answered. I guess the concept of freedom is closely related to conditioning. In addition quantum mechanics is not deterministic. Sure you know Einstein's famous phrase: "God does not play dice." As I said at the beginning of the interview, in quantum physics, every time you look, the reality is changing in a more or less random, not deterministic But the truth is that all these concepts have now scientifically isolated, the concept of life, consciousness, freedom, etc. We can not connect to each other. And I like that they can be connected scientifically, but as I say are concepts that currently have them isolated.
P. In short, Mr. Cirac, please let us a comment as a final thought. R. Just wanted to thank you for your kindness. It has been an unusual interview, but I enjoyed it.
P. Mr. Cirac, has been a pleasure to keep this interview with you. I must confess that I also enjoyed. I blame that what began as an interview has been transformed into a dialogue. Congratulations for winning the Prince of Asturias Award for Technical and Scientific Research 2006. We hope and we wish Mr. Cirac, which is not the last to add to his extraordinary scientific career. R. For me too it was a pleasure, really. Thank you. ______________________
Vicente Fernández María Desantes 