Carlo Rovelli quotes

Carlo Rovelli is an Italian theoretical physicist known for his work on quantum gravity and the philosophy of science. His research has contributed significantly to our understanding of loop quantum gravity and the nature of time. He is also a bestselling author, making science accessible and fascinating to a broad audience. Here are 28 of his quotes:

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.

Carlo Rovelli

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

Carlo Rovelli

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.

Carlo Rovelli

Children grow up and discover that the world is not as it seemed within the four walls of their homes. Humankind as a whole does the same.

Carlo Rovelli

In his youth Albert Einstein spent a year loafing aim- lessly. You don't get anywhere by not ‘wasting' time – something, unfortunately, which the parents of teenagers tend frequently to forget.

Carlo Rovelli

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.

Carlo Rovelli

Don't trust your teachers.

Carlo Rovelli

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.

Carlo Rovelli

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.

Carlo Rovelli

The World is Made of Events, not Things.

Carlo Rovelli

Time is... the expression of our ignorance of the full microstate.

Carlo Rovelli

[T]ime is much more elastic than our intuition of this rigid passage... The time interval between one point and another... depends on where you are.

Carlo Rovelli

If we had a starship, we could move near a black hole, stay there for a half hour and then come out. Outside hundreds of years could have gone. So we could... come away from the black hole into the far future easily.

Carlo Rovelli

The difference between past and future... cause and effect... memory and hope... regret and intention... in the elementary laws that describe the mechanisms of the world, there is no such difference.

Carlo Rovelli

If we formulate the fundamental theory of nature in a timeless language, we have then the problem of recovering the familiar notion of time.

Carlo Rovelli

General relativity has changed our understanding of space and time. ...The spacetime of general relativity ...is likely to be just a classical approximation that loses its meaning in the quantum theory, for the same reason the trajectory of a particle does.

Carlo Rovelli

I... interpret mechanics as a theory of relations between variables, rather than the theory of the evolution of variables in time.

Carlo Rovelli

[I]n a fundamental description of nature we must "forget time"... this can be done in the classical and in the quantum theory.

Carlo Rovelli

The notion of time familiar to us may... be reconstructed in special physical situations, or within an approximation, as... the "surface of a liquid" disappears ...[at] the atomic level, or "temperature" ...makes sense only in certain physical situations and when there are enough degrees of freedom.

Carlo Rovelli

While non-relativistic time is the observable quantity measured (or approximated) by physical clocks, in general relativity clocks measure s along their worldline, not t. The relativistic... t is a freely chosen label with no direct physical interpretation. ...The physical content of a solution of Einstein's equations is not in its dependence on t, but ...in what remains once the dependence on t (and x) has been factored away.

Carlo Rovelli

The way evolution is treated in general relativity, is... subtle... Change is not described as evolution of physical variables as a function of a preferred independent observable time variable. Instead, it is described in terms of a functional relation among equal footing variables... as... (T1,T2)... In general relativity, there isn't a preferred and observable quantity that plays the role of independent parameter of the evolution... General relativity describes the relative evolution of observable quantities, not the evolution of quantities as functions of a preferred one. ...[w]ith general relativity we have understood that the Newtonian "big clock" ticking away the "true universal time" is not there.

Carlo Rovelli

The thermal time hypothesis. In nature, there is no preferred physical time variable t. There are no equilibrium states ρ0 preferred a priori. Rather, all variables are equivalent; we can find the system in an arbitrary state ρ; if the system is in a state ρ, then a preferred variable is singled out by the state of the system. This variable is what we call time.

Carlo Rovelli