"What is Life" Reading Notes#
Author: [Austria] Erwin Schrödinger
Reading Duration: 1 hour
These are the notes and excerpts I recorded while reading "What is Life" on WeChat Reading.
What is Life?#
A free person rarely thinks about death; his wisdom is not the silent contemplation of death, but the deep reflection on life.
Existence is eternal; for many laws preserve the treasures of life; and the universe draws beauty from these treasures. — Goethe
The ever-changing phenomena linger, and you will be fixed in eternal thoughts. — Goethe
The increase in mutations is strictly proportional to the dose of radiation, and thus one can indeed say (as I have said) that it is an increasing coefficient.
Therefore, mutations are not an accumulation effect produced by the mutual enhancement of continuous small doses of radiation. A mutation must occur as a single event in a chromosome during the period of radiation.
If you widely change the nature of the rays (wavelength), from soft X-rays to quite hard gamma rays, the coefficient remains unchanged as long as you give the same dose calculated in the so-called roentgen units, that is to say, the dose you use is calculated based on the total number of ions produced in a unit volume of a selected standard substance at the place where the organism is irradiated during the exposure.
If ionization (or excitation) occurs within a range of no more than "ten atomic distances" from a specific point on the chromosome, there is a chance of producing a mutation. We will discuss this in more detail now.
And your spirit's fiery imagination silently conveys an image, a metaphor. — Goethe
Indeed, just as light reveals itself, it also reveals darkness; thus, truth is its own standard, and so is falsehood. — Spinoza, "Ethics," Part II, Proposition 43
The body cannot determine the soul to think, nor can the soul determine the body to move, be still, or engage in other activities. — Spinoza, "Ethics," Part III, Proposition 2
Life seems to be the ordered and regulated behavior of matter; it is not entirely based on its tendency from order to disorder, but is partially based on the existing order that is maintained.
In some very advanced countries (I can't remember if it was Germany or the United States, or both), you will find that in restaurants, the menu not only lists prices but also indicates the energy content of each dish. Needless to say, this is quite absurd. Because the energy contained in an adult organism is as fixed and unchanging as the matter it contains. Since any calorie is of equal value to any other calorie, it is indeed incomprehensible what pure exchange could be useful for.
Therefore, the clumsy expression of "negative entropy" can be replaced with a better phrase: entropy with a negative sign, which is itself a measure of order. Thus, an organism stabilizes itself at a relatively high level of order (equivalent to a relatively low level of entropy) by continuously drawing order from its environment. This conclusion is somewhat more reasonable than it initially appears. However, it may be criticized for being rather cumbersome. In fact, as far as higher animals are concerned, we know this order; they live entirely on it, that is to say, the state of matter in the organic substances of varying complexity that they consume as food is highly ordered. After animals utilize this food, what they excrete is greatly degraded material, but not completely decomposed, because plants can still utilize it. (Of course, plants obtain the most powerful supply of "negative entropy" from sunlight.)
If a person never contradicts himself, it must be because he never says anything. — Unamuno
These facts are undoubtedly the most interesting facts revealed by contemporary science. We may find that they are ultimately not unacceptable. An organism concentrates the "flow of order" within itself, thus avoiding a decline into atomic chaos — "drawing order" from a suitable environment — this astonishing gift seems to be related to the existence of "non-periodic solids," namely, chromosome molecules. These solids undoubtedly represent the highest level of ordered atomic aggregates we know — much higher than the order of ordinary periodic crystals — as each atom and each free radical plays its role within the solid.
In biology, we face a completely different situation. Single clusters of atoms that exist only in one copy orderly produce some events and make incredible adjustments among themselves and with the environment according to the most subtle laws. I say that they exist only in one copy because we still have examples of eggs and unicellular organisms. In the later stages of higher biological development, the number of copies increases, that is true. But to what extent does it increase? I know that in mature mammals, some can reach 10 to the power of 14. What is that? It is only one millionth of the number of molecules in a cubic inch of air. Although the number is quite large, when they coalesce, they only form a small drop of liquid. Look at how they are actually distributed. Each cell contains exactly one of these copies (or two, if we remember diploids), and since we know that the power of this tiny central organ is in isolated cells, doesn't each cell act like a branch of a local government that conveniently communicates messages using a common code throughout the body?
Precisely because such examples have not been previously proposed, our beautiful statistical theories did not include them. Our statistical theories are something to be proud of because they reveal the underlying mechanisms, drawing our attention to the solemn order of precise physical laws derived from the disorder of atoms and molecules; and because they reveal that the most important, most universal, and all-encompassing law of increasing entropy can be understood without special assumptions, since entropy is nothing more than the disorder of molecules themselves.
However, the view that the friction effects and thermal effects in a clock are negligible may be a practical perspective; while the second view that does not ignore these effects is undoubtedly a more fundamental view, even when we are faced with a clock powered by a spring moving regularly, this is still a fundamental view. Because it does not believe that the operating mechanism has truly left the statistical nature of the process. The real physical picture includes the possibility that even a normally functioning clock, by consuming heat energy from the environment, could immediately reverse its motion and work backward, rewinding its spring. The likelihood of such an event, compared to the "Brownian motion outbreak" of a clock without a driving mechanism, is exactly "six of one, half a dozen of the other."
When does a physical system — a combination of atoms — show "dynamical laws" (in the Planck sense) or "characteristics of clockwork"? Quantum theory has a brief answer to this question: at absolute zero. As the temperature approaches zero, the disorder of molecules no longer has significance for physical events. By the way, this fact was not discovered through theory, but was found by carefully studying chemical reactions over a wide range of temperatures and extrapolating the results to zero — absolute zero is practically unattainable — and discovered. This is the famous "thermal theorem" of W. Nernst, which is not an exaggeration to say that this theorem is sometimes honored with the title of "third law of thermodynamics" (the first law is the principle of energy, the second law is the principle of entropy).
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