Quotes About Quantum

I think that the obscurity of the theory is not the fault of quantum mechanics but is rather due to the limited capacity of our imagination. When we try to "see" the quantum world, we are rather like moles used to living underground, to whom someone is trying to describe the Himalayas. Or like the men imprisoned at the back of Plato's cave.

Therefore, the first meaning of quantum mechanics is the existence of a limit to the information that can exist within a system: a limit to the number of distinguishable states in which a system can be. This limitation upon infinity, this granularity of nature glimpsed by Democritus, is the first central aspect of the theory. Planck's constant h measures the elementary scale of this granularity.

Remember that a key result of quantum mechanics is precisely the fact that information is finite. The number of alternative results that we can obtain measuring a physical system* is infinite in classical mechanics; but thanks to quantum theory, we have understood that, in reality, it is finite. Quantum mechanics can be understood as the discovery that information in nature is always finite.

The entire formal structure of quantum mechanics can be in large measure expressed in two simple postulates:1 The relevant information in any physical system is finite. You can always obtain new information on a physical system.

Carlo Rovelli

A handful of elementary ingredients that act like bricks in a gigantic Lego set, and with which the entire material reality surrounding us is constructed. The nature of these particles, and the way they move, is described by quantum mechanics.

The world described by the theory is thus further distanced from the one with which we are familiar. There is no longer space that "contains" the world, and there is no longer time "in which" events occur. There are only elementary processes wherein quanta of space and matter continually interact with one another.

The origin of time may be similar to that of heat: it comes from averages of many microscopic variables. Let's see this in detail.

When we say that the volume of a room is, for example, one hundred cubic meters, we are in effect counting the grains of space-the "quanta of the gravitational field"-that it contains. In a room, this number has more than one hundred digits. When we say that the area of this page is forty-five square inches, we are actually counting the number of links in the web, or loops, that traverse the page. Across the page of this book, there is a number of quanta with more or less seventy digits.

Even if we observe a small, empty region of space in which there are no atoms, we still detect a minute swarming of these particles.

the gravitational field is not diffused through space; the gravitational field is that space itself.

Quantum gravity is the discovery that no infinitely small point exists. There is a lower limit to the divisibility of space.

The "quantum leaps" from one orbit to another constitute their way of being real: an electron is a combination of leaps from one interaction to another.

Despite certain obscurities,

The theory also gives information on which value of the spectrum will manifest itself in the next interaction, but only in the form of probabilities. We do not know with certainty where the electron will appear, but we can compute the probability that it will appear here or there.

The physical substratum that determines duration and physical intervals—the gravitational field—does not only have a dynamic influenced by masses; it is also a quantum entity that does not have determined values until it interacts with something else. When it does, the durations are granular and determinate only for that something with which it interacts; they remain indeterminate for the rest of the universe.

the "singularity" that classic general relativity anticipated disappears as soon as we take quantum gravity into account.

Why are precisely these elements listed there, and why does the periodic table have this particular structure, with these periods, and with the elements having these specific properties? The answer is that each element corresponds to one solution of the main equation of quantum mechanics. The whole of chemistry emerges from a single equation.

The apparent determinism of the macroscopic world is due only to the fact that the microscopic randomness cancels out on average, leaving only fluctuations too minute for us to perceive in everyday life.

Loop theory describes this atomic and granular quantum structure of space in a precise mathematical form. It is obtained by applying the general equations of quantum mechanics written by Dirac to Einstein's gravitational field. In particular, loop theory specifies that volume (for example the volume of a given cube) cannot be arbitrarily small. A minimum volume exists. No space smaller than this minimum volume exists. There is a minimum "quantum" of volume: an elementary atom of space.

The world of quantum mechanics is not a world of objects: it is a world of events.

the obscurity of the theory is not the fault of quantum mechanics but is rather due to the limited capacity of our imagination.

In quantum mechanics no object has a definite position, except when colliding headlong with something else. In order to describe it in mid-flight, between one interaction and another, we use an abstract mathematical formula that has no existence in real space, only in abstract mathematical space.

More than a hundred years have passed since we learned that the "present of the universe" does not exist.