Its impact has moved me a great deal. There may be objective reasons for this. I could give a more convincing explanation if I could contact every reader separately. I often think that if there was a way of recording readers’ association of ideas and thoughts a new «Autobiography of Light» would emerge – more interesting perhaps and undoubtedly richer than mine. How long did it take you to write the book? Ten years. A short time, given that the same light has been here for 14 billion years. Inside me, of course, I started writing it much earlier. A lonely path Is it a path paved by «Berenice’s Coiffure»? A lonely path, at first. I was unknown then, and few were convinced of the book’s value. But it gained more and more clout with the readers themselves. And this is its 17th year. Of successive editions. A new updated edition is planned with a CD of the narration accompanied by Andreas Georgotas’s music inspired by the book. Your second book moves away from popularizing science. «Cosmographimata» has a more personal tone. Apart from scientific subjects, it also addresses culture and education. An extract from the book was set as an essay topic for the university entrance exams. Yes. I was not surprised but very pleased – but anxious too, of course. At any rate, the popularization of science bothers me. I don’t think I am popularizing science but trying to see it through other eyes and link it to human struggles and passions. How is light speed linked to time, and why is it an impenetrable barrier that allows no ray or matter to pass through? It is a different speed from others. Apart from its incredible magnitude – as we blink light has circled the world seven times – the speed of light remains stable, whether its source or the observer moves. This, of course, goes against Newtonian physics and our logic. Einstein’s genius acknowledged that the speed of light is stable worldwide. In addition, all the laws of physics must be invariable, that is, they have the same mathematical form wherever they are applied: on Earth or on a moving train. These apparently simple admissions have led to a radical upheaval in the way we regard space, time and light, giving rise to a specific theory on relativity, which has a simple, comprehensible structure, but whose consequences are unpredictable and stunning. Time has ceased to be absolute; the size of a particle contracts as its speed increases; mass – that is matter – is equivalent to energy. The speed of light therefore is not just any speed but has become a fundamental property of the universe. The reason is unknown. Only by formulating a uniform theory, which contains all the fundamental processes of the world in just a few equations, will we perhaps find the answer. Why is there an obsession with uniform theory, for a mathematical and rational perception of the world? Physicists are indeed fixated on uniform theory, which is called with some presumption the «theory of the universe.» This theory hopes to interpret the birth and development of the universe, and its natural size on the basis of only a few fundamental particles of matter and the interaction between them. I don’t know whether this quest expresses a psychological or philosophical need, but it is however certainly justified by the progress of science. Thus, Democritus satisfactorily interpreted the complex structure of material bodies with the notion of atoms, an idea incredible for that time. For centuries, electricity and magnetism were believed to be separate and unconnected phenomena; today we know that they are the manifestation of only one interaction, electromagnetism. Later electromagnetic force was integrated with the weak force that causes radioactive fission, maybe in the future school textbooks will call it the electroweak interaction. Even the unification of the electroweak force with the strong force that gives matter its compactness is currently making good progress. Gravity is the badly behaved child that stubbornly refuses to conform, to integrate into a uniform structure. Have you thought of writing the autobiography of that mischievous child? I don’t write easily. «The Autobiography of Light» practically killed me, it was a real slog. An autobiography of gravity is of course highly interesting, as this force dominates the cosmic plane. Today we suspect the existence of anti-gravity that accelerates the distance between the galaxies. But gravity has already been written about by Newton and Einstein. A third biography by someone who does not possess the virtues of the two is perhaps not necessary. Are Newton and Einstein equals? In everyday terms, yes. No one needs a general theory of relativity to calculate how an apple falls from an apple tree or at what speed a car must turn a corner so as not be catapulted off the road. Newton’s laws suffice. Einstein’s theory though, which is very complex mathematically, surpasses the cosmic and aesthetic plane. It is profound in its conception and incorporates the idea of development as well as the beginning of the universe.