Quotes from Carlo Rovelli

Clues put us on the right path toward a correct theory. Strong evidence is that which subsequently allows us to trust whether the theory we have built is a good one or not. Without

Perhaps the rivers of ink that have been expended discussing the nature of the "continuous" over the centuries, from Aristotle to Heidegger, have been wasted. Continuity is only a mathematical technique for approximating very finely grained things. The world is subtly discrete, not continuous. The good Lord has not drawn the world with continuous lines: with a light hand, he has sketched it in dots, like the painter Georges Seurat.

And it is at this point that 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. This is the idea of the general theory of relativity. Newton's "space," through which things move, and the "gravitational field" are one and the same thing.

Perhaps it is we who have not yet learned to look at it from just the right point of view, one that would reveal its hidden simplicity.

The entropy of a system depends explicitly on blurring. It depends on what I do not register, because it depends on the number of indistinguishable configurations. The same microscopic configuration may be of high entropy with regard to one blurring and of low in relation to another.

Time is our ignorance.

The fact that we live at the bottom of a deep gravity well, on the surface of a gas-covered planet going around a nuclear fireball 90 million miles away, and think this to be normal, is obviously some indication of how skewed our perspective tends to be.'104

Quanta of space mingle with the foam of spacetime, and the structure of things is born from reciprocal information that weaves the correlations among the regions of the world.

Empowered by new conceptual tools and by mathematics, Einstein writes the equations which describe Democritus's void and finds for its 'certain physics' a colourful and amazing world where universes explode, space collapses into bottomless holes, time slows down in the vicinity of a planet, and the boundless expanses of interstellar space ripple and sway like the surface of the sea

Poetry and science are both manifestations of the spirit that creates new ways of thinking the world, in order to understand it better. Great science and great poetry are both visionary, and sometimes may arrive at the same insights. The culture of today that keeps science and poetry so far apart is essentially foolish, to my way of thinking, because it makes us less able to see the complexity and the beauty of the world as revealed by both.

Too often scientists sell hypothetical theories to the large public, as if they were established theories. I have seen this often done, for instance, with string theory. I think this is a great mistake, because it questions the credibility itself of science. We scientists live out of public money and it is our duty to be fully honest in reporting what we know and what we do not know. We are paid to dream, but we must not sell our dreams for established realities.

All of this, I believe, indicates that in order to grasp the basic grammar of the world, we need to merge three basic ingredients, not just two: not just general relativity and quantum mechanics, but also the theory of heat, that is, statistical mechanics and thermodynamics, which we can also describe as "information theory.

The mystery of time has always troubled us, stirring deep emotions. So deep as to have nourished philosophies and religions.

Our "present" does not extend throughout the universe. It is like a bubble around us.

What Copernicus, Newton, Einstein, and many others did was to build upon preexisting theories that synthesized empirical knowledge across vast fields of nature, and to find a way of combining and rethinking them, to improve the general picture.

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.

It is in order to escape this anxiety that we have imagined the existence of "eternity," a strange world outside of time that we would like to be inhabited by gods, by a God, or by immortal souls.

We must distinguish between clues and strong evidence. Clues are what set Sherlock Holmes on the right track, allowing him to solve a mysterious case. Strong evidence is what the judge needs to sentence the guilty. Clues put us on the right path toward a correct theory. Strong evidence is that which subsequently allows us to trust whether the theory we have built is a good one or not. Without clues, we search in the wrong directions. Without evidence, a theory is not reliable.

quantum mechanics cannot deal with the curvature of spacetime, and general relativity cannot account for quanta. This is the problem of quantum gravity.

Los dioses se alejan cada día un poco más en sus cielos. El hombre se queda solo, a merced de un mundo en revolución. Las líneas que Jaynes escribe sobre este período son muy bellas. En ellas percibimos el eco del célebre lamento [Tablilla «Ludlul bel nemeqi», figura 19]: Mi dios me abandonó y desapareció. Mi diosa me visita con menos frecuencia y se mantiene distante. El ángel bueno que caminaba a mi lado se fue…

Wonder is the source of our desire for knowledge,1 and the discovery that time is not what we thought it was opens up a thousand questions.

Undistracted by schooling, one studies best during vacations

I chose as my supervisor a professor who allowed me to continue to study what I wanted.

Probability does not refer to the evolution of matter in itself. It relates to the evolution of those specific quantities we interact with.