Sam Z > Sam's Quotes

“For Aristotle, physics works as follows: first, it is necessary to distinguish between the heavens and Earth. In the heavens, everything is made up of a crystalline substance that moves in a circular motion and turns eternally around Earth in great concentric circles, with the spherical Earth at the center of everything. On Earth, on the other hand, it is necessary to distinguish between forced motion and natural motion. Forced motion is caused by a thrust and ends when the thrust ends. Natural motion is vertical—upward or downward—and depends both on the substance and the location. Each substance has a “natural place,” that is to say, a proper altitude to which it always returns; earth at the bottom, water a little way above it, air a little higher still, and fire even higher. When you pick up a stone and let it fall, the stone moves downward because it wants to return to its natural level. Air bubbles in water, fire in the air, or children’s flying balloons move upward instead, again seeking their natural place.”
― Carlo Rovelli, Reality Is Not What It Seems: The Journey to Quantum Gravity

“If we see a child playing on the beach, it is only because between him and ourselves there is this lake of vibrating lines that transport his image to us. Is the world not marvelous?”
― Carlo Rovelli, Reality Is Not What It Seems: The Journey to Quantum Gravity

“We see the world around us in color. What is color? Put simply, it is the frequency (the speed of oscillation) of the electromagnetic wave light is. If the wave vibrates more rapidly, the light is bluer. If it vibrates a little more slowly, the light is redder. Color as we perceive it is our psychophysical reaction of the nerve signal generated by the receptors of our eyes, which distinguish electromagnetic waves of different frequencies.”
― Carlo Rovelli, Reality Is Not What It Seems: The Journey to Quantum Gravity

“Only someone in his twenties can take such delirious propositions seriously. You have to be a twentysomething to believe that they can be turned into a theory of the world.”
― Carlo Rovelli, Reality Is Not What It Seems: The Journey to Quantum Gravity

“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.”
― Carlo Rovelli, Reality Is Not What It Seems: The Journey to Quantum Gravity

“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.”
― Carlo Rovelli, Reality Is Not What It Seems: The Journey to Quantum Gravity

“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.”
― Carlo Rovelli, Reality Is Not What It Seems: The Journey to Quantum Gravity

“This is Dirac’s quantum mechanics: a recipe for calculating the spectra of the variables, and a recipe for calculating the probability that one or another value in the spectrum appears during an interaction.”
― Carlo Rovelli, Reality Is Not What It Seems: The Journey to Quantum Gravity

“What happens between one interaction and the next is not mentioned in the theory. It does not exist.”
― Carlo Rovelli, Reality Is Not What It Seems: The Journey to Quantum Gravity

“Dirac’s quantum mechanics thus allows us to do two things. First, to calculate which values a physical variable may assume. This is called “calculation of the spectrum of a variable”; it captures the granular nature of things.”
― Carlo Rovelli, Reality Is Not What It Seems: The Journey to Quantum Gravity

“Dirac’s quantum mechanics thus allows us to do two things. First, to calculate which values a physical variable may assume. This is called “calculation of the spectrum of a variable”; it captures the granular nature of things. When an object (atom, electromagnetic field, molecule, pendulum, stone, star, and the like) interacts with something else, the values computed are those that its variables can assume in the interaction (relationism). The second thing that Dirac’s quantum mechanics allows us to do is to compute the probability that this or that value of a variable appears at next interaction. This is called “calculation of an amplitude of transition.” Probability expresses the third feature of the theory: indeterminacy, the fact that it does not give unique predictions, only probabilistic ones.”
― Carlo Rovelli, Reality Is Not What It Seems: The Journey to Quantum Gravity

“The present is like the flatness of Earth: an illusion. We imagined a flat Earth because of the limitations of our senses, because we cannot see much beyond our own noses. Had we lived on an asteroid of a few kilometers in diameter, like Antoine de Saint-Exupéry’s Little Prince, we would have easily realized we were on a sphere. Had our brain and our senses been more precise, had we easily perceived time in nanoseconds, we would never have made up the idea of a “present” extending everywhere. We would have easily recognized the existence of the intermediate zone between past and future. We would have realized that saying “here and now” makes sense, but that saying “now” to designate events “happening now” throughout the universe makes no sense. It is like asking whether our galaxy is “above or below” the galaxy of Andromeda: a question that makes no sense, because “above” or “below” has meaning on the surface of Earth, not in the universe. There isn’t an “up” and a “down” in the universe. Similarly, there isn’t always a “before” and an “after” between two events in the universe. The resulting knitted structure that space and time form together, depicted in figures like 3.2 and 3.3, is what physicists call “spacetime” (figure 3.4).”
― Carlo Rovelli, Reality Is Not What It Seems: The Journey to Quantum Gravity

“Between the past and the future of an event (for example, between the past and the future for you, where you are, and in the precise moment in which you are reading), there exists an “intermediate zone,” an “extended present”; a zone that is neither past nor future. This is the discovery made with special relativity. The duration of this “intermediate zone,”* which is neither in your past nor in your future, is very small and depends on where an event takes place relative to you, as illustrated in figure 3.2: the greater the distance of the event from you, the longer the duration of the extended present. At a distance of a few meters from your nose, the duration of what for you is the “intermediate zone,” neither past nor future, is no more than a few nanoseconds: next to nothing (the number of nanoseconds in a second is the same as the number of seconds in thirty years). This is much less than we could possibly notice. On the other side of the ocean, the duration of this “intermediate zone” is a thousandth of a second, still well below the threshold of our perception of time, the minimum amount of time we perceive with our senses, which is somewhere on the order of a tenth of a second. But on the moon, the duration of the “extended present” is a few seconds, and on Mars it is a quarter of an hour. This means we can say that on Mars there are events that in this precise moment have already happened, events that are yet to happen, but also a quarter-of-an-hour of events during which things occur that are neither in our past nor in our future. They are elsewhere. We had never before been aware of this “elsewhere” because next to us this “elsewhere” is too brief; we are not quick enough to notice it. But it exists, and is real. This is why it is impossible to hold a smooth conversation between here and Mars. Say I am on Mars and you are here; I ask you a question and you reply as soon as you’ve heard what I said; your reply reaches me a quarter of an hour after I had posed the question. This quarter of an hour is time that is neither past nor future to the moment you’ve replied to me. The key fact that Einstein understood is that this quarter of an hour is inevitable: there is no way of reducing it. It is woven into the texture of the events of space and of time: we cannot abbreviate it, any more than we can send a letter to the past. It’s strange, but this is how the world happens to be.”
― Carlo Rovelli, Reality Is Not What It Seems: The Journey to Quantum Gravity

“The present is like the flatness of Earth: an illusion. We imagined a flat Earth because of the limitations of our senses, because we cannot see much beyond our own noses. Had we lived on an asteroid of a few kilometers in diameter, like Antoine de Saint-Exupéry’s Little Prince, we would have easily realized we were on a sphere. Had our brain and our senses been more precise, had we easily perceived time in nanoseconds, we would never have made up the idea of a “present” extending everywhere. We would have easily recognized the existence of the intermediate zone between past and future. We would have realized that saying “here and now” makes sense, but that saying “now” to designate events “happening now” throughout the universe makes no sense. It is like asking whether our galaxy is “above or below” the galaxy of Andromeda: a question that makes no sense, because “above” or “below” has meaning on the surface of Earth, not in the universe. There isn’t an “up” and a “down” in the universe. Similarly, there isn’t always a “before” and an “after” between two events in the universe. The resulting knitted structure that space and time form together, depicted in figures like 3.2 and 3.3, is what physicists call “spacetime” (figure 3.4). Figure 3.4 What is the world made of?”
― Carlo Rovelli, Reality Is Not What It Seems: The Journey to Quantum Gravity

“Democritus himself, who had placed empty space at the basis of his world where atoms course, certainly wasn’t crystal clear on the issue: he wrote that empty space is something “between being and non-being”:”
― Carlo Rovelli, Reality Is Not What It Seems: The Journey to Quantum Gravity

“during the war”
― Truman Capote, Breakfast at Tiffany's

“Let me build you a drink.”
― Truman Capote, Breakfast at Tiffany's

“A gentleman from Japan.”
― Truman Capote, Breakfast at Tiffany's

“She was still on the stairs, now she reached the landing, and the ragbag colors of her boy’s hair, tawny streaks, strands of albino-blond and yellow, caught the hall light. It was a warm evening, nearly summer, and she wore a slim cool black dress, black sandals, a pearl choker. For all her chic thinness, she had an almost breakfast-cereal air of health, a soap and lemon cleanness, a rough pink darkening in the cheeks.”
― Truman Capote, Breakfast at Tiffany's

“She played very well, and sometimes sang too. Sang in the hoarse, breaking tones of a boy’s adolescent voice.”
― Truman Capote, Breakfast at Tiffany's

“Listen, you can throw me out if you want to. I’ve got a gall barging in on you like this.”
― Truman Capote, Breakfast at Tiffany's

“information is the measure of the number of possible alternatives for something. For example, if I throw a die, it can land on one of six faces.”
― Carlo Rovelli, Reality Is Not What It Seems: The Journey to Quantum Gravity

“For Plato, forms exist by themselves, in an ethereal ideal world of forms, a world of “ideas.” The idea of a horse exists prior to and independently of any actual horse. For Plato, a real horse is nothing but a pale reflection of the idea of a horse. The atoms that make up the horse count for little: what counts is the “horseness,” the abstract form.”
― Carlo Rovelli, Reality Is Not What It Seems: The Journey to Quantum Gravity

“Boltzmann was not taken seriously. At the age of fifty-six, in Duino, near Trieste, he committed suicide. Today he is considered one of the geniuses of physics.”
― Carlo Rovelli, Reality Is Not What It Seems: The Journey to Quantum Gravity

“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.”
― Carlo Rovelli, Reality Is Not What It Seems: The Journey to Quantum Gravity

“Any description of a system is therefore always a description of the information a system has about another system, that is to say, the correlation between the two systems. The”
― Carlo Rovelli, Reality Is Not What It Seems: The Journey to Quantum Gravity

“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, Reality Is Not What It Seems: The Journey to Quantum Gravity

“It from bit”
― Carlo Rovelli, Reality Is Not What It Seems: The Journey to Quantum Gravity

“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.”
― Carlo Rovelli, Reality Is Not What It Seems: The Journey to Quantum Gravity

“It is always heat and only heat that distinguishes the past from the future.”
― Carlo Rovelli, Reality Is Not What It Seems: The Journey to Quantum Gravity