Ok, I admit to some of my sins. I picked this up to make myself feel better on my loafing, which is something that keeps happening often! I might be deluding myself... or not.
The fabrics of reality, as we try to understand it now, is described in this book in a visionary language. We are able to follow a journey through centuries, to see links between the greatest mind influencers of all ages.
I do too feel better about myself and my lapses in 'daily toil'. Cheers!!!
Q:
In his youth Albert Einstein spent a year loafing aimlessly. You don’t get anywhere by not ‘wasting’ time – something, unfortunately, which the parents of teenagers tend frequently to forget. He was in Pavia. He had joined his family having abandoned his studies in Germany, unable to endure the rigours of his high school there. It was the beginning of the twentieth century, and in Italy the beginning of its industrial revolution. His father, an engineer, was installing the first electrical power plants in the Paduan plains. Albert was reading Kant and attending occasional lectures at the University of Pavia: for pleasure, without being registered there or having to think about exams. It is thus that serious scientists are made. (c)
Q:
Einstein became a renowned scientist overnight and received offers of employment from various universities. (c)
Q:
It would take ten years to resolve. Ten years of frenzied study, attempts, errors, confusion, mistaken articles, brilliant ideas, misconceived ideas. (c)
Q:
‘The General Theory of Relativity’, his masterpiece and the ‘most beautiful of theories’, according to the great Russian physicist Lev Landau.
There are absolute masterpieces which move us intensely: Mozart’s Requiem; Homer’s Odyssey; the Sistine Chapel; King Lear. To fully appreciate their brilliance may require a long apprenticeship, but the reward is sheer beauty – and not only this, but the opening of our eyes to a new perspective upon the world. Einstein’s jewel, the general theory of relativity, is a masterpiece of this order. (c)
Q:
Undistracted by schooling, one studies best during vacations. vacations. I was studying with the help of a book that had been gnawed at the edges by mice, because at night I’d used it to block the holes of these poor creatures in the rather dilapidated, hippy-ish house on an Umbrian hillside where I used to take refuge from the tedium of university classes in Bologna. Every so often I would raise my eyes from the book and look at the glittering sea: it seemed to me that I was actually seeing the curvature of space and time imagined by Einstein. As if by magic: as if a friend was whispering into my ear an extraordinary hidden truth, suddenly raising the veil of reality to disclose a simpler, deeper order. (c)
Q:
an extraordinary idea occurred to him, a stroke of pure genius: the gravitational field is not diffused through space; the gravitational field is that space itself. (c)
Q:
The student in question, Bernhard Riemann, had produced an impressive doctoral thesis of the kind that seems completely useless. The conclusion of Riemann’s thesis was that the properties of a curved space are captured by a particular mathematical object which we know today as Riemann’s curvature, and indicate with the letter ‘R’. Einstein wrote an equation which says that R is equivalent to the energy of matter. That is to say: space curves where there is matter. That is it. The equation fits into half a line, and there is nothing more. A vision – that space curves – became an equation. (c) I love how this allows a layman (a laywoman in my case) to get a rare glimpse into the inner sanctum: the workings of the mind of a visionary!
Q:
But within this equation there is a teeming universe. And here the magical richness of the theory opens up into a phantasmagorical succession of predictions that resemble the delirious ravings of a madman, but which have all turned out to be true.
To begin with, the equation describes how space bends around a star. Due to this curvature, not only do planets orbit round the star, but light stops moving in a straight line and deviates. Einstein predicted that the sun causes light to deviate. In 1919 this deviation was measured, and the prediction verified. But it isn’t only space that curves; time does too. Einstein predicted that time passes more quickly high up than below, nearer to the Earth. This was measured and turned out to be the case. If a man who has lived at sea level meets up with his twin who has lived in the mountains, he will find that his sibling is slightly older than him. And this is just the beginning. (c)
Q:
In short, the theory describes a colourful and amazing world where universes explode, space collapses into bottomless holes, time sags and slows near a planet, and the unbounded extensions of interstellar space ripple and sway like the surface of the sea … And all of this, which emerged gradually from my mice-gnawed book, was not a tale told by an idiot in a fit of lunacy, or a hallucination caused by Calabria’s burning Mediterranean sun and its dazzling sea. It was reality.
Or better, a glimpse of reality, a little less veiled than our blurred and banal everyday view of it. A reality which seems to be made of the same stuff which our dreams are made of, but which is nevertheless more real than our clouded quotidian dreaming. (c)
Q: Perhaps anyone reading this will still be able to appreciate its wonderful simplicity:
Rab − ½ R gab = Tab
That’s it.
You would, of course, need to study and digest Riemann’s mathematics in order to master the technique to read and use this equation. It takes a little commitment and effort. But less than is necessary to come to appreciate the rarefied beauty of a late Beethoven string quartet. In both cases the reward is sheer beauty, and new eyes with which to see the world. (c)
Q:
Quanta
...
The work of Einstein was initially treated by colleagues as the nonsensical juvenilia of an exceptionally brilliant youth. (c)
Q:
Heisenberg imagined that electrons do not always exist. They only exist when someone or something watches them, or better, when they are interacting with something else. They materialize in a place, with a calculable probability, when colliding with something else. The ‘quantum leaps’ from one orbit to another are the only means they have of being ‘real’: an electron is a set of jumps from one interaction to another. When nothing disturbs it, it is not in any precise place. It is not in a ‘place’ at all.
It’s as if God had not designed reality with a line that was heavily scored, but just dotted it with a faint outline. (c)
Q:
This lesson is made up mostly of simple drawings. The reason for this is that before experiments, measurements, mathematics and rigorous deductions, science is above all about visions. Science begins with a vision. Scientific thought is fed by the capacity to ‘see’ things differently than they have previously been seen. I want to offer here a brief, modest outline of a journey between visions. (c)
Q:
A world of happenings, not of things. (c)
Q:
So, for the moment we have to stay with the Standard Model. It may not be very elegant, but it works remarkably well at describing the world around us. And who knows? Perhaps on closer inspection it is not the model that lacks elegance. Perhaps it is we who have not yet learnt to look at it from just the right point of view; one which would reveal its hidden simplicity. (c)
Q:
A handful of types of elementary particles, which vibrate and fluctuate constantly between existence and non-existence and swarm in space even when it seems that there is nothing there, combine together to infinity like the letters of a cosmic alphabet to tell the immense history of galaxies, of the innumerable stars, of sunlight, of mountains, woods and fields of grain, of the smiling faces of the young at parties, and of the night sky studded with stars. (c)Unexpectedly poetic.
Q:
A university student attending lectures on general relativity in the morning and others on quantum mechanics in the afternoon might be forgiven for concluding that his professors are fools, or have neglected to communicate with each other for at least a century. In the morning the world is curved space where everything is continuous; in the afternoon it is a flat space where quanta of energy leap.
The paradox is that both theories work remarkably well. (c)
Q:
It is not the first time that physics finds itself faced with two highly successful but apparently contradictory theories. The effort to synthesize has in the past been rewarded with great strides forward in our understanding of the world. Newton discovered universal gravity by combining Galileo’s parabolas with the ellipses of Kepler. Maxwell found the equations of electromagnetism by combining the theories of electricity and of magnetism. Einstein discovered relativity by way of resolving an apparent conflict between electromagnetism and mechanics. A physicist is only too happy when he finds a conflict of this kind between successful theories: it’s an extraordinary opportunity. Can we build a conceptual framework for thinking about the world which is compatible with what we have learnt about it from both theories?
Here, in the vanguard, beyond the borders of knowledge, science becomes even more beautiful – incandescent in the forge of nascent ideas, of intuitions, of attempts. Of roads taken and then abandoned, of enthusiasms. In the effort to imagine what has not yet been imagined. (c)
Q:
The illusion of space and time which continues around us is a blurred vision of this swarming of elementary processes, just as a calm, clear Alpine lake consists in reality of a rapid dance of myriads of minuscule water molecules. (c)
Q:
We realize that we are full of prejudices and that our intuitive image of the world is partial, parochial, inadequate. ... If we try to put together what we have learnt in the twentieth century about the physical world, the clues point towards something profoundly different from our instinctive understanding of matter, space and time. Loop quantum gravity is an attempt to decipher these clues, and to look a little further into the distance. (c)
Q:
Why does heat go from hot things to cold things, and not vice versa?
It is a crucial question, because it relates to the nature of time. In every case in which heat exchange does not occur, or when the heat exchanged is negligible, we see that the future behaves exactly like the past. For example, for the motion of the planets of the solar system heat is almost irrelevant, and in fact this same motion could equally take place in reverse without any law of physics being infringed. As soon as there is heat, however, the future is different from the past. While there is no friction, for instance, a pendulum can swing forever. If we filmed it and ran the film in reverse we would see movement that is completely possible. But if there is friction then the pendulum heats its supports slightly, loses energy and slows down. Friction produces heat. And immediately we are able to distinguish the future (towards which the pendulum slows) from the past. We have never seen a pendulum start swinging from a stationary position, with its movement initiated by the energy obtained by absorbing heat from its supports. The difference between past and future only exists when there is heat. The fundamental phenomenon that distinguishes the future from the past is the fact that heat passes from things that are hotter to things that are colder.
So, again, why, as time goes by, does heat pass from hot things to cold and not the other way round?
The reason was discovered by Boltzmann, and is surprisingly simple: it is sheer chance.
Boltzmann’s idea is subtle, and brings into play the idea of probability. Heat does not move from hot things to cold things due to an absolute law: it only does so with a large degree of probability. The reason for this is that it is statistically more probable that a quickly moving atom of the hot substance collides with a cold one and leaves it a little of its energy, rather than vice versa. Energy is conserved in the collisions, but tends to get distributed in more or less equal parts when there are many collisions. In this way the temperature of objects in contact with each other tends to equalize. It is not impossible for a hot body to become hotter through contact with a colder one: it is just extremely improbable. (c)
Q:
Einstein wrote a moving letter to Michele’s sister: ‘Michele has left this strange world a little before me. This means nothing. People like us, who believe in physics, know that the distinction made between past, present and future is nothing more than a persistent, stubborn illusion.’ (c)
Q:
Within the immense ocean of galaxies and stars we are in a remote corner; amidst the infinite arabesques of forms which constitute reality we are merely a flourish among innumerably many such flourishes. (c)
Q:
Myths nourish science, and science nourishes myth. But the value of knowledge remains. If we find the antelope we can eat. (c)
Q:
The information which one physical system has about another has nothing mental or subjective about it: it’s only the connection that physics determines between the state of something and the state of something else. A raindrop contains information on the presence of a cloud in the sky; a ray of light contains information on the colour of the substance from which it came; a clock has information on the time of day; the wind carries information about an approaching storm; a cold virus has information of the vulnerability of my nose; the DNA in our cells contains all the information in our genetic code (on what makes me resemble my parents); and my brain teems with information accumulated from my experience. The primal substance of our thoughts is an extremely rich gathering of information that’s accumulated, exchanged and continually elaborated. (c)
Q:
It is not against nature to be curious: it is in our nature to be so.
One hundred thousand years ago our species left Africa, compelled perhaps by precisely this curiosity, learning to look ever further afield. Flying over Africa by night, I wondered if one of these distant ancestors setting out towards the wide open spaces of the North could have looked up into the sky and imagined a distant descendant flying up there, pondering on the nature of things, and still driven by the very same curiosity. (c)
Q:
I believe that our species will not last long. It does not seem to be made of the stuff that has allowed the turtle, for example, to continue to exist more or less unchanged for hundreds of millions of years; for hundreds of times longer, that is, than we have even been in existence. We belong to a short-lived genus of species. All of our cousins are already extinct. What’s more, we do damage. The brutal climate and environmental changes which we have triggered are unlikely to spare us. For the Earth they may turn out to be a small irrelevant blip, but I do not think that we will outlast them unscathed – especially since public and political opinion prefers to ignore the dangers which we are running, hiding our heads in the sand. We are perhaps the only species on Earth to be conscious of the inevitability of our individual mortality. I fear that soon we shall also have to become the only species that will knowingly watch the coming of its own collective demise, or at least the demise of its civilization.
...
And it’s certainly not the first time that this will have happened. The Maya and Cretans, amongst many others, have already experienced this. We are born and die as the stars are born and die, both individually and collectively. This is our reality. Life is precious to us because it is ephemeral. And as Lucretius wrote: ‘our appetite for life is voracious, our thirst for life insatiable’ (De rerum natura, III, 1084). But immersed in this nature which made us and which directs us, we are not homeless beings suspended between two worlds, parts of but only partly belonging to nature, with a longing for something else. No: we are home.
Nature is our home, and in nature we are at home. This strange, multicoloured and astonishing world which we explore – where space is granular, time does not exist, and things are nowhere – is not something that estranges us from our true selves, for this is only what our natural curiosity reveals to us about the place of our dwelling. About the stuff of which we ourselves are made. We are made of the same stardust of which all things are made, and when we are immersed in suffering or when we are experiencing intense joy we are being nothing other than what we can’t help but be: a part of our world. (c)
Q:
It is part of our nature to love and to be honest. It is part of our nature to long to know more, and to continue to learn. Our knowledge of the world continues to grow.
There are frontiers where we are learning, and our desire for knowledge burns. They are in the most minute reaches of the fabric of space, at the origins of the cosmos, in the nature of time, in the phenomenon of black holes, and in the workings of our own thought processes. Here, on the edge of what we know, in contact with the ocean of the unknown, shines the mystery and the beauty of the world. And it’s breathtaking. (c)