Quotes About Entropy

Entropy derives from the Greek "conversion", "mutation", "evolution", but also "confusion" and "shame" (this latter meaning one finds in the writings of Hippocrates in the form ).

In 1877 he published his paper "Probabilistic foundations of heat theory", in which he formulated what Einstein later called the Boltzmann principle; the interpretation of the concept of entropy as a mathematically well-defined measure of what one can call the "disorder" of atoms, which had already appeared in his work of 1872, is here extended and becomes a general statement.

It is entropy, not energy, that keeps stones on the ground and the world turning.

We are stories, contained within the twenty complicated centimeters behind our eyes, lines drawn by traces left by the (re)mingling together of things in the world, and oriented toward predicting events in the future, toward the direction of increasing entropy, in a rather particular corner of this immense, chaotic universe.

if nothing else around it changes, heat cannot pass from a cold body to a hot one......This is the only basic law of physics that distinguishes the past from the future.

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 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.

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.

There is no preferred direction of time without heat.

a star must ignite for hydrogen to begin to burn there into helium. What causes stars to ignite? Another process that increases entropy: the contraction due to gravity of one of the large clouds of hydrogen that sail throughout the galaxy.

is Entropy, not Energy, that Drives the World

The difference between past and future exists only when there is heat. The fundamental phenomenon that distinguishes the future from the past is the fact that heat passes from things

The difference between past and future exists only 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.

The growth of entropy is nothing other than the ubiquitous and familiar natural increase of disorder.

This is what Boltzmann understood. The difference between past and future does not lie in the elementary laws of motion; it does not reside in the deep grammar of nature. It is the natural disordering that leads to gradually less particular, less special situations.

The difference between past and future exists only 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. So,

We observe the universe from within it, interacting with a minuscule portion of the innumerable variables of the cosmos. What we see is a blurred image. This blurring suggests that the dynamic of the universe with which we interact is governed by entropy, which measures the amount of blurring. It measures something that relates to us more than to the cosmos.

Heat, entropy, and the lower entropy of the past are notions that belong to an approximate, statistical description of nature.

This is the disconcerting conclusion that emerges from Boltzmann's work: the difference between the past and the future refers only to our own blurred vision of the world. It's a conclusion that leaves us flabbergasted: Is it really possible that a perception so vivid, basic, existential—my perception of the passage of time—depends on the fact that I cannot apprehend the world in all of its minute detail?

It isn't true, as is sometimes stated, that life generates structures that are particularly ordered, or that locally diminish entropy: it is simply a process that degrades and consumes the low entropy of food; it is a self-structured disordering, no more and no less than in the rest of the universe.

Later on, I will delve into the mystery of this blurring, to see how it is tied to the strange initial improbability of the universe. For now, I will end with the mind-boggling fact that entropy, as Boltzmann fully understood, is nothing other than the number of microscopic states that our blurred vision of the world fails to distinguish.

In tutti i casi in cui non viene scambiato calore, infatti, oppure quando il calore scambiato è trascurabile, noi vediamo che il futuro si comporta esattamente come il passato.

it is simply a process that degrades and consumes the low entropy of food; it is a self-structured disordering, no more and no less than in the rest of the universe.

The crucial point here is the difference from what happens with falling bodies: a ball may fall, but it can also come back up, by rebounding, for instance. Heat cannot. This is the only basic law of physics that distinguishes the past from the future.