Seth Lloyd

Seth Lloyd The Computational Universe, in „Information and the Nature of Reality“, From Physics to Metaphysics, ed. Paul Davies/Niels Gregersen, Oxford 2010

92 Seth Lloyd The computational universe:

We are in the midst of an information-processing revolution based on electronic computers and optical communication systems. This revolution has transformed work, education, and thought, and has affected the life of every person on earth.

The effect of the digital revolution on humanity as a whole, however, pales when compared with the effect of the previous information-processing revolution: the invention of movable type. The invention of the printing press was an information-processing revolution of the first magnitude. Movable type allowed the information in each book, once accessible only to the few people who possessed the book‘s hand-copied text, to be accessible to thousands or millions of people. The resulting widespread literacy and dissemination of information, completely transformed society. Access to the written word empowered individuals not only in their intellectual lives, but in their economic, legal, and religious lives as well.

Similarly, the effect of the printed word is small when compared with the effect of the written word. Writing - the discovery that spoken words could be put into correspondence with marks on clay, stone, or paper - was a huge information-processing revolution. The existence of complicated, hierarchical societies with extended division of labour depends crucially on writing.

Just as printing is based on writing, writing stems from one of the greatest information-processing revolution in the history of our planet: the development of the spoken word. Human language is a remarkable form of information-processing, capable of expressing, well, anything that can be put into words. Human language includes within it the capacity to perform sophisticated analysis, such as mathematics and logic, as well as the personal calculations that underlie the complexity of human society. Although other animals have utterance, it is not clear that any of them possess the same capacity for universal language that humans do. Ironically, the entities that possess the closest approximation to human language are our own creations: digital computers, whose computer languages possess a form of universality bequeathed to them by human language. It is the social organisation stemming from human language (together with the written language, the printed word, computers, etc) that have made human beings so successful as a species.

Before turning to even earlier information-processing revolutions, it is worth to saying a few words about how human language came about. Who discovered human language? Fossil skulls suggest that human brains underwent significant change over a period of time, with the size of the cortex expanding tenfold. The result was our species, Homo sapiens: „man with knowledge“ (literally, man with taste). 94 Once you can reason, there is great pressure to develop the form of utterance that embodies that reason. Groups of Homo sapiens who could elaborate their way of speaking to reflect their reasoning would have a substantial evolutionary advantage over other groups who were incapable of complex communication and who were therefore unable to turn their thoughts into concerted action.

95 The mother of all information-processing revolution is life itself. However it came about, the mechanism of storing genetic information in DNA, and reproducing the variation, is a truly remarkable invention that gave rise to the beautiful and rich world around us. Life is the original information-processing revolution. Or is it? Life arose on Earth sometime in the last five billion years. Meanwhile, the universe itself is a little less than fourteen billion years old. Were the intervening nine billion years completely devoid of information-processing revolutions? The answer to this question is „No“. Life is not the original information-processing revolution.

The very first information-processing revolution, from which all other revolution stem, began with the beginning of the universe itself. The big bang at the beginning of time consisted of huge numbers of elementary particles, colliding at temperatures of billions of degrees. Each of these particles carried with it bits of information, and every time two particles bounced off each other, those bits were transformed and processed. The big bang was a bit bang.Starting from its very earliest moments, every piece of the universe was processing information. The universe computes. It is this ongoing computation of the universe itself that gave rise naturally to subsequent information-processing revolutions such is life, sex, brains, language, and electronic computers.

96 the computational universe
102 It has been known since the end of the 19th century that if the universe can be regarded as a machine (the mechanistic paradigm), it is a machine that processes information. In the 1990s, researchers in quantum computation showed that the universe was capable of full-blown digital computation at its most microscopic levels: the universe is, technically, a giant quantum computer.

The computational paradigms for the universe supplements the ordinary mechanistic paradigm: the universe is not just a machine, it is a machine that processes information. The universe computes. The universe is a physical system that can be programmed at its most microscopic level to perform universal digital computation. Quantum mechanics is constantly injecting fresh, random bits into the universe. Because of its computational nature, the universe processes and interprets those bits, naturally giving rise to all sorts of complex order and structure.

Aristotle, when he had finished writing his Physics, wrote his Metaphysics: literally „the book after physics“. This chapter has discussed the physics of the computing universe and its implications for the origin of complexity and order. Let us use the physics of the computing universe as a basis for its metaphysics.

Seth Lloyd at Perimeter Institute - 2011
photosythesis – qantum algorithm – quantum computation – quantum search
qubit – is 0 and 1 at the same time – quantom multitasking
classical random walk – quantum random walk: more efficient
quantum tunnelling – quantum decoherence – temperature range – entangled states – quantum coding
robins can sense the magnetic field of the earth
Smell – receptors – I smell a quantum - vibrations – frequency
life uses quantum effects