Best 33 quotes of Carlo Rovelli on MyQuotes

An overly pragmatic attitude is not productive on the long run.

Don't trust your teachers.

Einstein’s 1905 paper came out and suddenly changed people’s thinking about space-time. We’re again in the middle of something like that. When the dust settles, time—whatever it may be—could turn out to be even stranger and more illusory than even Einstein could imagine.

I think that physics is about escaping the prison of the received thoughts and searching for novel ways of thinking the world, about trying to clear a bit the misty lake of insubstantial dreams, which reflect reality like the lake reflects the mountains.

I think that the resistance against Darwin is not just the difficulty of seeing the power of a spectacularly beautiful explanation: it is the fear of realizing the extraordinary power that such an explanation has in shattering rests of old world views.

I worry that free imagination is overvalued, and I think this carries risks.

Listening a cultivated person of today that jokes and almost boasts about his scientific ignorance, is as sad as listening a scientist that boasts about not having read any poem.

Rationality and the instinct of collaboration have already given us large regions and long periods of peace and prosperity. Ultimately, they will lead us to a planet without countries, without wars, without patriotism, without religions, without poverty, where we will be able to share the world. Actually, maybe I am not sure I truly believe that I believe this, but I do want to believe that I believe this.

The new coherent picture is not yet available. With all their immense empirical success, G(eneral)R(elativity) and Q(uantum)M(echanics) have left us with an understanding of the physical world which is unclear and badly fragmented. At the foundations of physics there is today confusion and incoherence.

The very foundation of science is to keep the door open to doubt. Precisely because we keep questioning everything, especially our own premises, we are always ready to improve our knowledge. Therefore a good scientist is never ‘certain’. Lack of certainty is precisely what makes conclusions more reliable than the conclusions of those who are certain: because the good scientist will be ready to shift to a different point of view if better elements of evidence, or novel arguments emerge. Therefore certainty is not only something of no use, but is in fact damaging, if we value reliability.

We never really see time. We see only clocks. If you say this object moves, what you really mean is that this object is here when the hand of your clock is here, and so on. We say we measure time with clocks, but we see only the hands of the clocks, not time itself. And the hands of a clock are a physical variable like any other. So in a sense we cheat because what we really observe are physical variables as a function of other physical variables, but we represent that as if everything is evolving in time.

A precious miracle that the infinite play of combinations has unlocked for us, allowing us to exist. We may smile now. We can go back to serenely immersing ourselves in time - in our finite time - to savoring the clear intensity of every fleeting and cherished moment of the brief circle of our existence.

A university student attending lectures on general relativity i the morning and others on quantum mechanics in the afternoon might be forgiven for thinking that his professors are fools, or have neglected to communicate with each other for at least a century.

Change is ubiquitous. Only: elementary processes cannot be ordered along a common succession of instants. At the extremely small scale of the quanta of space, the dance of nature does not develop to the rhythm kept by the baton of a single orchestral conductor: every process dances independently with its neighbours, following its own rhythm. The passing of time is intrinsic to the world, it is born of the world itself, out of the relations between quantum events which are the world and which themselves generate their own time.

General relativity and quantum mechanics are in the end not as incompatible as they seemed. On closer inspection, they shake hands and engage in a beautiful dialogue. The spatial relations that weave Einstein's curved space are the very interactions weaving the relations between the systems of quantum mechanics. The two become compatible and conjoined, two sides of the same coin, as soon as it is recognized that space and time are aspects of a quantum field, and quantum fields can exist without being grounded in an external space.

It is hardly surprising that there are more things in heaven and earth, dear reader, than have been dreamed of in our philosophy - or in our physics.

Le equazioni della meccanica quantistica e le loro conseguenze vengono usate quotidianamente da fisici, ingegneri, chimici e biologi, nei campi più svariati. Sono utilissime per tutta la tecnologia contemporanea. Non ci sarebbero i transistor senza la meccanica quantistica. Eppure restano misteriose: non descrivono cosa succede a un sistema fisico, ma solo come un sistema fisico viene percepito da un altro sistema fisico. Che significa? Significa che la realtà essenziale di un sistema è indescrivibile? Significa solo che manca un pezzo alla storia? O significa, come a me sembra, che dobbiamo accettare l’idea che la realtà sia solo interazione?

Our moral values, our emotions, our loves are no less real for being part of nature, for being shared with the animal world, or for being determined by the evolution which our species has undergone over millions of years. Rather, they are more valuable as a result of this: they are real. They are the complex reality of which we are made. Our reality is tears and laughter, gratitude and altruism, loyalty and betrayal, the past which haunts us and serenity.

Science is born from this act of humility: not trusting blindly in our past knowledge and our intuition. Not believing what everyone says. Not having absolute faith in the accumulated knowledge of our fathers and grandfathers. We learn nothing if we think we already know the essentials, if we assume that they were written in a book or known by the elders of the tribe. The centuries in which people had faith in what they believed were the centuries in which little new was learned. Had they trusted the knowledge of their fathers, Einstein, Newton, and Copernicus would never have called things into question and would never have been able to move our knowledge forward (259, trsl. Carnell & Segre)

Se non si perde tempo non si arriva da nessuna parte, cosa che i genitori degli adolescenti purtroppo dimenticano spesso.

Si noti il meraviglioso «Mi sembra...» iniziale, che ricorda l’«Io penso...» con cui Darwin introduce nei suoi taccuini la grande idea che le specie evolvono, o l’«esitazione» di cui parla Faraday quando nel suo libro introduce la rivoluzionaria idea di campo elettrico. Il genio esita.

The atoms of our body, as well, flow in and away from us. We, like waves and like all objects, are a flux of events; we are processes, for a brief time monotonous

[T]he elementary form of the mechanics of the world...does not need to mention 'time.' The world without a time variable is not a complicated one. It's a net of interconnected events, where the variables in play adhere to probabilistic rules that, incredibly, we know for a good part how to write. And it's a clear world, windswept and full of beauty as the crests of mountains; aridly beautiful as the cracked lips of the adolescent you loved.

The entropy of the world in the far past appears very low to us. But this might not reflect the exact state of the world: it might regard the subset of the world' s variables with which we, as physical systems, have interacted. It is with respect to the dramatic blurring produced by our interactions with the world, caused by the small set of macroscopic variables in terms of which we describe the world, that the entropy of the universe was low.

The very foundation of science is to keep the door open to doubt.

.... the world is made entirely from quantum fields. These fields do not live *in* spacetime; they live, so to speak, one on top of the other: fields on fields. The space and time that we perceiv in large scale are our blurred and approximage image of one of these quantum fields: the gravitational field (193).

This is time for us. Memory. A nostalgia. The pain of absence. But it isn't absence that causes sorrow. It is affection and love. Without affection, without love, such absences would cause us no pain. For this reason, even the pain caused by absence is in the end something good and even beautiful. Because it feeds on that which gives meaning to life.

To the very last, the desire to challenge oneself and understand more. And to the very last: doubt.

To trust immediate intuitions rather than collective examination that is rational, careful, and intelligent is not wisdom: it is the presumption of an old man who refuses to believe that the great world outside his village is any different from the one that he has always known.

Undistracted by schooling, one studies best during vacations

We are a species which is naturally moved by curiosity, the only one left of a group of species (the genus Homo) made up of a dozen equally curious species. The other species in the group have already become extinct; some, like the Neanderthals, quite recently, roughly thirty thousand years ago. It is group of species which evolved in Africa, akin to the hierarchical and quarrelsome chimpanzees -- and even more closely akin to the bonobos, the small, peaceful, cheerfully egalitarian and promiscuous type of chimps. A group of species which repeatedly went out of Africa in order to explore new worlds, and went far: as far, eventually, as Patagonia -- and as far, eventually, as the moon. It is not against our nature to be curious: it is in our nature to be so.

When Einstein died, his greatest rival, Bohr, found for him words of moving admiration. When a few years later Bohr in turn died, someone took a photograph of the blackboard in his study. There’s a drawing on it. A drawing of the ‘light-filled box’ in Einstein’s thought experiment. To the very last, the desire to challenge oneself and understand more. And to the very last: doubt

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.