Seven Brief Lessons on Physics

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. Nature is behaving with us like that elderly rabbi to whom two men went in order to settle a dispute. Having listened to the first, the rabbi says: ‘You are in the right.’ The second insists on being heard, the rabbi listens to him and says: ‘You’re also right.’ Having overheard from the next room the rabbi’s wife then calls out, ‘But they can’t both be in the right!’ The rabbi reflects and nods before concluding: ‘And you’re right too.’

The confusion between these two diverse human activities—inventing stories and following traces in order to find something—is the origin of the incomprehension and distrust of science shown by a significant part of our contemporary culture. The separation is a subtle one: the antelope hunted at dawn is not far removed from the antelope deity in the night’s storytelling.
The border is porous. Myths nourish science, and science nourishes myth. But the value of knowledge remains. If we find the antelope, we can eat.

“A handful of types of elementary particles, which vibrate and fluctuate constantly between existence and nonexistence 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.“

Pretty nebulae.... because look how cool they are!

¹ Apparently time flows² faster up high - faster in the mountains than at the sea level.

² Except that time doesn’t really *flow*. Or exist. It’s just that our consciousness is limited. Also, heat is involved.

“Ever since we discovered that Earth is round and turns like a mad spinning-top, we have understood that reality is not as it appears to us: every time we glimpse a new aspect of it, it is a deeply emotional experience. Another veil has fallen.“

“When we talk about the big bang or the fabric of space, what we are doing is not a continuation of the free and fantastic stories that humans have told nightly around campfires for hundreds of thousands of years. It is the continuation of something else: of the gaze of those same men in the first light of day looking at tracks left by antelope in the dust of the savannah—scrutinizing and deducting from the details of reality in order to pursue something that we can’t see directly but can follow the traces of. In the awareness that we can always be wrong, and therefore ready at any moment to change direction if a new track appears; but knowing also that if we are good enough we will get it right and will find what we are seeking. This is the nature of science.”

The heat of black holes is like the Rosetta Stone of physics, written in a combination of three languages – Quantum, Gravitational and Thermodynamic – still awaiting decipherment in order to reveal the true nature of time.

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.

Ma c'è di peggio: questi salti con cui ogni oggeto passa a un'interazione all'altra non avvengono in modo previsibile, ma largamente a caso. Non è possibile prevedere dove en elettrone comparirà di nuovo, ma solo calcolere la probabilità che appaia qui o lì. La probabilità fa capolino nel cuore della fisica, là dove sembrava tutto fosse regolato da leggi precise, univoche e inderogabile.

But this is ?the point?: these jumps with which each object passes from one interaction to another do not happen in a predictable way, but largely by chance. It is not possible to predict where an electron will ?turn up? again, but only calculate the probability that it appears here or there. Probability makes ?? in the heart of physics, there where it seemed all was regulated by laws precise, unequivocal and unbreakable.