Reality is not what it Seems
A review of Reality is not what it Seems by Rob Mason
“A living organism is a system which continually re-forms itself in order to remain itself, interacting ceaselessly with the external world. Of such organisms, only those continue to exist which are more efficient at doing so and, therefore, living organisms manifest properties which have suited them for survival. For this reason, they are interpretable, and we interpret them, in terms of intentionality, of purpose. The finalistic aspects of the biological world are therefore the result of the selection of complex forms effective in persisting. But the effective way of continuing to exist in a changing world is to manage correlations with the external world better, that is to say, information; to collect, store, transmit and elaborate information. For this reason, DNA exists, together with immune systems, sense organs, nervous systems, complex brains, language, books, the library of Alexandria, computers and Wikipedia: they maximise the efficiency of information management – the management of correlations favouring survival.
Even from this brief overview it should be clear that the notion of information plays a central role in our attempts to understand the world. From communication to the basis of genetics, from thermodynamics to quantum mechanics and up to quantum gravity, the notion of information is gaining ground as a tool for understanding. The world should not be understood as an amorphous ensemble of atoms – but rather as a game of mirrors, founded on the correlations between the structures formed by combinations of these atoms.
As Democritus said, it is not just a question of these atoms but also of the order in which they are arranged. Atoms are like the letters of the alphabet: an extraordinary alphabet, so rich as to be able to read, reflect and even think about itself.
Democritus gave a strange definition of “man.” ‘Man is what we all know.’ At first sight, this seems rather silly and empty, but it is not so.
Salomon Luria, the major scholar of Democritus, observes that it is not a banality that Democritus is giving us. The nature of man is not his internal structure but the network of personal, familial and social interactions within which he exists. It is these which ‘make’ us, these which guard us. As humans, we are that which others know of us, that which we know of ourselves, and which others know of our knowledge. We are complex nodes in a rich web of reciprocal information.”
Michael Faraday and James Clerk Maxwell: The electromagnetic field
Of all the scientific discoveries, few have had a greater impact on our lives than that of the electromagnetic field. We use it whenever we turn on a radio or television, make a call on a cell phone, or travel in a radar-guided aircraft. It’s hard for us to imagine living in a world where such things don’t exist, yet we rarely give thought to the two men who made them possible. By discovering the electromagnetic field Faraday and Maxwell transformed our everyday lives. Even more significantly, they changed the way that scientists think about the physical world.
Michael Faraday was born in 1791. Son of a poor London blacksmith, he had only rudimentary schooling but took advantage of an apprenticeship with a bookbinder to read all the books on scientific topics that came into the shop and, by skill, flair and determination, rose to become the country’s foremost experimental scientist. In the course of an epic series of experiments, he discovered the principles of the electric motor and the dynamo, and began to form his own theory on why electricity and magnetism behaved as they did. He believed that electric and magnetic "lines of force" existed in space, but the idea was ridiculed by many of his contemporaries. Much as they admired Faraday’s experimental genius, they thought him ill-equipped to theorize because he knew no mathematics. Moreover, he had challenged the strictly mechanical view of the universe that had prevailed since Newton’s time (1643 – 1727).
It took another genius to show that Faraday’s extraordinary idea was correct: space itself held energy and transmitted forces. James Clerk Maxwell was born forty years after Faraday and his upbringing could hardly have been more different. The son of a Scottish laird, he studied at Cambridge University, where he came second in the famous Mathematical Tripos exam. In an astonishing and short career (he died at age forty-eight), Maxwell made fundamental discoveries in every branch of physics he turned his hand to -- he even took the world’s first color photograph -- but, as with Faraday, his greatest work was in electricity and magnetism.
To Maxwell, Faraday’s ideas about lines of force rang true, and he set out to express them in mathematical terms. By using imaginary mechanical models, first of fluid flow and then of tiny spinning cells interspaced with even smaller "idle wheels," he showed not only that all the known properties of electricity and magnetism could be derived mathematically from Faraday’s ideas but also that every time an electric current was switched on or off, a wave of electromagnetic energy would spread out through space at the speed of light. Finally, he dispensed with the models and derived all the equations, including the wave equation, using only the laws of dynamics. Faraday’s lines of electric and magnetic force had become the electromagnetic field.
It is characteristic of genius to be aware of the limitations of its own findings, even in the case of such momentous outcomes as Newton’s discovery of the laws of mechanics and universal gravity. Newton’s theory worked so well, it turned out to be so useful, that for two centuries no one bothered any longer to question it – until Faraday, the reader to whom Newton had bequeathed the unanswered question, found the key to understanding how bodies can attract and repel each other at a distance in a reasonable manner. Einstein will later apply Faraday’s brilliant solution to Newton’s own theory of gravity.
Introducing the new entity – the field – Faraday departs radically from Newton’s elegant and simple ontology: the world is no longer made up only of particles that move in space while time passes. A new actor – the field – appears on the scene. Faraday is aware of the importance of the step he is taking. There are beautiful passages in his book where he asks whether these lines of force could be things with a real existence. After doubts and different considerations, he concludes that he thinks they are indeed real, but with the hesitation that is necessary when faced with the deepest questions of science. He is conscious that he is suggesting nothing less than a modification of the structure of the world, after two centuries of uninterrupted successes for Newtonian physics.
Maxwell quickly realizes that gold has been struck with this idea. He translates Faraday’s insight, which Faraday only in words, into a page of equations. These are now known as Maxwell’s equations. They describe the behaviour of the electric and magnetic fields: the mathematical version of the ‘Faraday’ lines.
Today, Maxwell’s equations are used daily to describe all electric and magnetic phenomena, to design antennae, radios, electric engines and computers . And this is not all: these same equations are needed to explain how atoms function (they are held together by electric forces), and why the particles of the material that forms a stone adhere together, or how the Sun works. They describe an amazing number and range of phenomena. Almost everything that we witness taking place – with the exception of gravity, but little else besides – is well described by Maxwell’s equations.
But wait, there is more. There is still what is perhaps the most beautiful success of science: Maxwell’s equations tell us what light is.
Maxwell realizes that his equations predict that Faraday’s lines can tremble and undulate, just like the waves of the sea. He computes the speed at which the undulations of Faraday’s lines move and the result turns out to be … the same as for light! Why? Mawell understands: because light is nothing other than this rapid trembling of Faraday’s lines! Not only have Faraday and Maxwell figured out how electricity and magnetism work but, with the same stroke, as a collateral effect, they have figured out what light is.
We see the world around us in colour. What is colour? Put simply, it is the frequency (the speed of oscillation) of the electromagnetic wave that light is. If the wave vibrates more rapidly, the light is bluer. If it vibrates a little more slowly, the light is redder. Colour, as we perceive it, is the psychophysical reaction of the nerve signal generated by the receptors of our eyes, which distinguish electromagnetic waves of different frequencies.
Light is a rapid vibration of the spider-web of Faraday’s lines, which ripple like the surface of a lake as the wind blows. “To see” is to perceive light, and light is the movement of Faraday’s lines. If we see a child playing on the beach, it is only because between them and ourselves there is this lake of vibrating lines which transports their image to us.
Carlo Rovelli – Reality is not what it Seems