Tag Archives: Physics

The Second Law by PW Atkins

Summary

  1. PW Atkins’ beautiful book, The Second Law, defines what the second law means and how it impacts every facet of the world and our lives

Key Takeaways

  1. The Laws of Thermodynamics
    1. The name thermodynamics is a blunderbuss term originally denoting the study of heat, but now extended to include the study of the transformation of energy in all its forms. It is based on a few statements that constitute succinct summaries of people’s experiences with the way that energy behaves in the course of its transformations. These summaries are The Laws of Thermodynamics. Although we shall be primarily concerned with just one of these laws, it will be useful to have at least a passing familiarity with all of them. There are four laws. The third of them, the second law, was recognized first; the first, the zeroth law, was formulated last; the first law was second; the third law might not even be a law in the same sense as the others
      1. Zeroth Law
        1. The zeroth Law was a kind of logical afterthought. Formulated by about 1931, it deals with the possibility of defining the temperature of things. Temperature is one of the deepest concepts of thermodynamics, and I hope this book will sharpen your insight into its elusive nature. Simply, around thermal equilibrium and 
      2. First Law
        1. The first law is popularly stated as “energy is conserved.” 
      3. Second Law
        1. The second law recognizes that there is a fundamental dissymmetry in Nature: the rest of this book is focused on that dissymmetry. All around us are aspects of that dissymmetry: hot objects cool, but cool objects do not spontaneously become hot; a bouncing ball comes to rest, but a stationary ball does not spontaneously begin to bounce. Although the total quantity of energy must be conserved in any process, the distribution of that energy changes in an irreversible manner. The second law is concerned with the natural direction of change of the distribution of energy, something that is quite independent of its total quantity
        2. Energy drops from the hot source to the cold sink, and is conserved; but because we have set up this flow from hot to cold, we are able to draw only some energy off as work; so not all the energy drops into the cold. The cold sink appears to be essential, for only if it is available can we set up the energy fall, and draw off some as work. In every engine, there has to be a cold sink, and that at some stage of the cycle energy must be discarded into it. That little mouse of experience is nothing other than the second law of thermodynamics. All the law seems to be saying is that heat cannot be completely converted into work in a cyclic engine: some has to be discarded into a cold sink. That is, we appear to have identified a fundamental tax: Nature accepts the equivalence of heat and work, but demands a contribution whenever heat is converted into work. Note the dissymmetry. Nature does not tax the conversion of work into heat: we may fritter away our hard-won work by friction, and do so completely. It is only heat that cannot be so converted. Heat is taxed; work is not. 
          1. No process is possible in which the sole result is the absorption of heat from a reservoir and its complete conversion into work.
          2. Similarly, no process is possible in which the sole result is the transfer of energy from a cooler to a hotter body (flow from cold to hot is possible but not natural. Only the spontaneous shift of heat from cold to hot without there being change elsewhere is against nature..)
          3. Natural processes are accompanied by an increase in the entropy of the universe.
        3. The domain of the second law is corruption and decay
        4. One of the most important contributions of 19th century thermodynamics is our comprehension that work and heat are names of methods, not names of things…Both heat and work are terms relating to the transfer of energy. To heat an object means to transfer energy in a special way (making use of a temperature difference between the hot and the heated). To cool an object is the negative of heating it: energy is transferred out of the object under the influence of a difference in temperature between the cold and the cooled. It is most important to realize, and to remember throughout the following pages, that heat is not a form of energy: it is the name of a method of transferring energy. The same is true of work. Work is what you do when you need to change the energy of an object by a means that does not involve temperature difference. Thus, lifting a weight from the floor and moving a truck to the top of a hill involves work. Like heat, work is not a form of energy: it is the name of a method for transferring energy. 
        5. Work into Quality
          1. Suppose we have a certain amount of energy that we can draw from a hot source, and an engine to convert it into work. We know that the second law demands that we have a cold sink too; so we arrange for the engine to operate in the usual way. We can extract the appropriate quantity of work, and pay our tax to Nature by dumping a contribution of energy as heat into the cold sink. The energy we have dumped into the cold sink is then no longer available for doing work (unless we happen to have an even colder reservoir available). Therefore, in some sense, energy stored at a high temperature has a better “quality”: high-quality energy is available for doing work; low-quality energy, corrupted energy, is less available for doing work…Just as the increasing entropy of the universe is the signpost of natural change and corresponds to energy being stored at ever-lower temperatures, so we can say that the natural direction of change is the one that causes the quality of energy to decline: the natural processes of the world are manifestations of this corruption of quality
          2. Here is our first major result of thermodynamics: we now know how to minimize the heat we throw away: we keep the cold sink as cold as possible, and the hot source as hot as possible. That is why modern power stations use superheated steam: cold sinks are hard to come by; so the most economical procedure is to use as hot a source as possible. That is, the designer aims to use the highest-quality energy…There appears to be a limit to the lowness of temperature. The conversion efficiency of heat to work cannot exceed unity, for otherwise the first law would be contravened…Absolute zero appears to be unattainable
            1. Hottest possible source, coldest possible sink. This contrast offers the most efficient system
            2. Some deep thread with velocity, friction, superheated sources and super cooled sinks
          3. Quality must reflect the absence of chaos. High-quality energy must be undispersed energy, energy that is highly localized (as in a lump of coal or a nucleus of an atom); it may also be energy that is stored in the coherent motion of atoms (as in the flow of water)
        6. When we do work on a system, we are stimulating its particles with coherent motion; when we heat a system, we are stimulating its particles with incoherent motion
          1. Deep thread with coherence, superfluidity, work 
        7. Thermal equilibrium corresponds to the most probable state of the universe…So long as a process is occurring in which more chaos is generated than is being destroyed, then the balance of the energy may be withdrawn as coherent motion…The state of more chaos can allow greater coherence locally, so long as greater dissipation has occurred elsewhere…Order on any scale can arise from collapse into chaos: order springs locally from disorder elsewhere. Such is the spring of change. 
        8. Chaos determines not only destiny but also the rate at which that destiny is achieved
      4. Third Law
        1. The third law of thermodynamics deals with the properties of matter at very low temperatures. It states that we cannot bring matter to a temperature of absolute zero in a finite number of steps. 
    1. Fluid flows from a hot, thermally “high” source to a cold, thermally “low” sink
  2. Other
    1. Work and heat are mutually inter-convertible, and heat is not a substance like water
    2. An engine is something that converts heat into work. Work is a process such as raising a weight. Indeed, we shall define work as any process that is equivalent to the raising of a weight. Later, as this theory develops, we shall use our increased insight to build more general definitions and find the most all-embracing definition right at the end. That is one of the delights of science: the more deeply a concept is understood, the more widely it casts its net. 
      1. Work is a way of transferring energy between a system and its surroundings; it is a transfer effected in such a way that a weight could be raised in the surroundings as a result. When work is done on a system, the change in the surroundings is equivalent to the lowering of a weight.
    3. The godfathers of the field are Kelvin, Clausius, Carnot, and Boltzmann

What I got out of it

  1. The last half was a bit too technical for me but there were a couple fundamental ideas which were clarified around the second law of thermodynamics. Two of the biggest, for me, are that quality of energy = capacity for work (think this is a fascinating way to think about the elusive idea of “quality”) and the idea that the larger the contrast between the hot source and the cold sink, the more efficient the system is (this is an idea which can be applied to every facet of your life…seek out contrast…, aka competitive advantage…)

Latticework: The New Investing by Robert Hagstrom

Summary

  1. Latticework: success in investing based on a working knowledge of a variety of disciplines

Key Takeaways

  1. Latticework
    1. Latticework is itself a metaphor. And on the surface, quite a simple one at that. Everyone knows what latticework is, and most people have some degree of firsthand experience with it. There is probably not a do-it-yourselfer in America who hasn’t made good use of a four-by-eight sheet of latticework at some point. We  use it to decorate fences, to create shade over patios, and to support climbing plants. It is but a very small stretch to envision a metaphorical lattice as the support structure for organizing a set of mental concepts
  2. Physics – Equilibrium
    1. Physics is the science that investigates matter, energy, and the interaction between them – the study, in other words, of how our universe works. It encompasses all the forces that control motion, sound, light, heat, electricity, and magnetism, and their occurrence in all forms, from the smallest subatomic particles to entire solar systems. It is the intellectual foundation of many well-recognized principles such as gravitation and such mind-boggling concepts as quantum mechanics and relativity.
    2. Equilibrium is defined as a state of balance between opposing forces, powers, or influences. An equilibrium model typically identifies a system that is at rest; this is called “static equilibrium.”
    3. The concept of equilibrium is so deeply embedded in our theory of economics and the stock market, it is difficult to imagine any other idea of how these systems could possible work…One place where the question is being raised is the Santa Fe Institute, where scientists from several disciplines are studying complex adaptive systems – those systems with many interacting parts that are continually changing their behavior in response to changes in the environment…If a CAS is, by definition, continuously adapting, it is impossible for any such system, including the stock market, ever to reach a state of perfect equilibrium. What does that mean for the stock market? It throws the classic theories of economic equilibrium into serious question. The standard equilibrium theory is rational, mechanistic, and efficient. It assumes that identical individual investors share rational expectations about stock prices and then efficiently discount that information into the market. It further assumes there are no profitable strategies available that are not already priced into the market. The counterview from SFI suggests the opposite: a market that is not rational, is organic rather than mechanistic, and is imperfectly efficient. 
    4. The SFI pointed out 4 distinct features they observed about the economy: dispersed interaction, no global controller, continual adaptation, out of equilibrium dynamics. 
  3. Biology – Evolution
    1. What we are learning is that studying economic and financial systems is very similar to studying biological systems. The central concept for both is the notion of change, what biologists call evolution. The models we use to explain the evolution of financial strategies are mathematically similar to the equations biologists use to study populations of predator-prey systems, competing systems, or symbiotic systems. 
    2. Complex systems must be studied as a whole, not in individual parts, because the behavior of the system is greater than the sum of the parts. The old science was concerned with understanding the laws of being. The new science is concerned with the laws of becoming
  4. Social Sciences – Complexity, Complex Adaptive Systems, Self-Organized Criticality
    1. Although Johnson’s maze is a simple problem-solving computer simulation, it does demonstrate emergent behavior. It also leads us to better understand the essential characteristic a self-organizing system must contain in order to produce emergent behavior. That characteristic is diversity. The collective solution, Johnson explains, is robust if the individual contributions to the solution represent a broad diversity of experience in the problem at hand. Interestingly, Johnson discovered that the collective solution is actually degraded if the system is limited to only high-performing people. It appears that the diverse collective is better at adapting to unexpected changes in structure. 
      1. Folly to think you can eliminate every waste, every performer who doesn’t meet the highest bar, and excel and survive. Can shift the entire bell curve to the right, but you still need the full spectrum
      2. Notes: We have observed anecdotal evidence of emergent behavior, perhaps without realizing what we were seeing. The recent bestseller, Blind Man’s Bluff: The Untold Story of american Submarine Espionage, presents a very compelling example of emergence. Early in the book, the authors relate the story of the 1966 crash of a B-52 bomber carrying four atomic bombs. Three of the four bombs were soon recovered, but a fourth remained missing, with the Soviets quickly closing in. A naval engineer named John Craven was given the task of locating the missing bomb. He constructed several different scenarios of what possibly could have happened to the fourth bomb and asked the members of the salvage team to wager a bet on where they thought the bomb could be. He then ran each possible location through a computer formula and – without ever going to sea! – was able to pinpoint the exact location of the bomb based on a collective solution
    2. It is when the agents in the system do not have similar concepts about the possible choices that the system is in danger of becoming unstable. And that is clearly the case in the stock market…The value of this way of looking at complex systems is that if we know why they become unstable, then we have a clear path to a solution, to finding ways to reduce overall instability. One implication, Richards says, is that we should be considering the belief structures underlying the various mental concepts, and not the specifics of the choices. Another is to acknowledge that if mutual knowledge fails, the problem may center on how knowledge is transferred in the system. 
  5. Psychology – Mr. Market, Complexity, Information
    1. Another aspect of behavioral finance is what some psychologists refer to as mental accounting – our tendency to think of money in different categories, putting our funds into separate “mental accounts,” depending on circumstances. Mental accounting is the reason we are far more willing to gamble with our year-end bonus than our monthly salary, especially if it is higher than anticipated. It is also one further reason why we stubbornly hold onto stocks that are doing badly; the loss doesn’t feel like a loss until we sell
  6. Philosophy – Pragmatism
    1. Strictly for organizational simplicity, we can separate the study of philosophy into 3 broad categories. First, critical thinking as it applies to the general nature of the world is called “metaphysics”…Metaphysics means “beyond physics.” When philosophers discuss metaphysical questions, they are describing ideas that exist independently from our own space and time. Examples include the concepts of God and the afterlife. These are not tangible events like tables and chairs but rather abstract ideas that metaphysical questions readily concede the existence of the world that surrounds us but disagree about the essential nature and meaning of the world. The second body of philosophical inquiry is the investigation of 3 related areas: aesthetics, ethics, and politics. Aesthetics is the theory of beauty. Philosophers who engage in aesthetic discussions are trying to ascertain what it is that people find beautiful, whether it be in the objects they observe or in the state of mind they achieve. This study of the beautiful should not be thought of as a superficial inquiry, because how we conceive beauty can affect our judgments of what is right and wrong, what is the correct political order, and how people should live. Ethics is the philosophical branch that studies the issues of right and wrong. It asks what is moral and what is immoral, what behavior is appropriate and inappropriate. Ethics makes inquiries into the activities people undertake, the judgments they make, the values they hold, and the character they aspire to achieve. Closely connected to the idea of ethics is the philosophy of politics. Whereas ethics investigates what is good or right at the individual level, politics investigates what is good or right at the societal level. Political philosophy is a debate over how societies should be organized, what laws should be passed, and what connections people should have to these societal organizations. Epistemology, the third body of inquiry, is the branch of philosophy that seeks to understand the limits and nature of knowledge. The term itself comes from two Greek words: episteme, meaning “knowledge,” and logos, which literally means “discourse” and more broadly refers to any kind of study or intellectual investigation. Epistemology, then, is the study of the theory of knowledge. To put it simply, when we make an epistemological inquiry, we are thinking about thinking. When philosophers think about knowledge, they are trying to discover what kinds of things are knowable, what constitutes knowledge (as opposed to beliefs), how it is acquired (innately or empirically, through experience), and how we can say that we know a thing.
    2. For pragmatism, anyone who seeks to determine the true definition of a belief should look not at the belief itself but at the actions that result from it. He called the proposition “pragmatism,” a term, he pointed out, with the same root as practice or practical, thus cementing his view that the meaning of an idea is the same as its practical results. “Our idea of anything, Peirce explained, “is our idea of its sensible effects.” In his classic 1878 paper, “How to Make Our Ideas Clear,” Peirce continued: “The whole function of thought is to produce habits of action. To develop its meaning, we have, therefore, simply to determine what habits it produces, for what a thing means is simply what habits it involves.” 
    3. A belief is true, James said, because holding it puts a person into more useful relations with the world…People should ask what practical effects come from holding one philosophical view over another
    4. If truth ad value are determined by their practical applications in the world, then it follows that truth will change as circumstances change and as new discoveries about the world are made. Our understanding of truth evolves. Darwin smiles.
    5. So we can say that pragmatism is a process that allows people to navigate an uncertain world without becoming stranded on the desert island of absolutes. Pragmatism has no prejudices, dogmas, or rigid canons. It will entertain any hypothesis and consider any evidence. If you need facts, take the facts. If you need religion, take religion. If you need to experiment, go experiment. “In short, pragmatism widens the field of search for God,” says James. “Her only test of probable truth is what works best in the way of leading us.” 
    6. Pragmatism, in summary, is not a philosophy as much as it is a way of doing philosophy. It thrives on open minds, and gleefully invites experimentation. It rejects rigidity and dogma; it welcomes new ideas. It insists that all possibilities should be considered, without prejudice, for important new insights often come disguised as frivolous, even silly notions. it seeks new understanding by redefining old problems. 
    7. One of the secret to Bill Miller’s success is his desire to take a Rubik’s Cube approach to investing. He enthusiastically examines every issue from every possible angle, from every possible discipline, to get the best possible description – or redescription – of what is going on. Only then does he feel in a position to explain. To his investigation he brings insights from many fields…He continually studies physics, biology, and social science research, searching for ideas that will help him become a better investor…In an environment of rapid change, the flexible mind will always prevail over the rigid and absolute…Because you recognize patterns, you are less afraid of sudden changes. With a perpetually open mind that relishes new ideas and knows what to do with them, you are set firmly on the right path. 
  7. Literature – self-education of a Latticework through books, Adler’s Active Reading
    1. We must educate ourselves and the vehicle for doing so is a book supplemented with all other media both traditional and modern…So we are talking about learning to become discriminating readers: to analyze what you read, to evaluate its worth in the larger picture, and to either reject it or incorporate it into your own latticework of mental models…We can all acquire new insights through reading if we perfect the skill of reading thoughtfully. The benefits are profound: not only will you substantially add to your working knowledge of various fields, you will at the same time sharpen your skill at critical thinking.
    2. The central purpose of reading a book, Adler believes, is to gain understanding…This is not the same as reading for information. 
    3. Reading that makes you stop and think is the path to greater understanding – not solely because of what you are reading but also because of the process of reflection in which you are engaged. You are learning from your own thinking as well as from the author’s ideas. You are making new connections. Adler describes as the difference between learning by instruction and learning by discovery. It’s evident of in the satisfaction we feel when we figure out something on our own, instead of being told the answer. Receiving the answer might solve the immediate problem, but discovering the answer by your own investigation has a much more powerful effect on your overall understanding. 
    4. Adler proposes that all active readers need to keep 4 fundamental questions in mind: what is the book about as a whole, what is being said in detail, is the book true, in whole or in part, what of it? The heart of Adler’s process involves 4 levels of reading: elementary, inspectional, analytical, and syntopical. Each level is a necessary foundation for the next, and the entire process is cumulative. 
      1. Elementary reading is the most basic level, the one we achieve in elementary education
      2. In inspectional reading, the second level, the emphasis is on time and the goal is to determine, as quickly as possible, what the book is about. It has two levels: prereading and superficial reading. Prereading is a fast review to determine whether a book deserves a more careful reading. Look at the table of contents, index, how much can you learn about the main themes through this overview. Next, Adler recommends systematic skimming. Read a few paragraphs here and there, read the author’s conclusion. These two activities should take between 30-60 minutes and help you determine if it is worth your time to read the book
      3. Analytical reading is the most thorough and complete way to absorb a book. Through analytical reading you will answer what is the book about as a whole and in detail and provide you the most complete answer to if the book is true. It has  goals: develop a detailed sense of what the book contains, interpret the contents by examining the author’s own particular point of view on the subject; and to analyze the author’s success in presenting that point of view convincingly. Take notes, make an outline, write in your own words what you think the book is about, write the author’s main arguments
      4. The fourth and highest level is what Adler calls syntopical reading, or comparative reading. In this level of reading, we are interested in learning about a certain subject, and to do so we compare and contrast the works of several authors rather than focusing on just one work by one another. Adler considers this the most demanding and most complex level of reading. It involves two challenges: first, searching for possible books on the subject; and then deciding, after finding them, which books should be read
    5. The challenge for us as readers is to receive that knowledge and integrate it into our latticework of mental models. How well we are able to do so is a function of two very separate considerations: the author’s ability to explain, and our skills as careful, thoughtful readers. We have little control over the first, other than to discard one particular book in favor of another, but the second is completely within our control
    6. I believe in…mastering the best that other people have figured out, [rather than] sitting down and trying to dream it up yourself…You won’t find it that hard if you go at it Darwinlike, step by step with curious persistence. You’ll be amazed at how good you can get…It’s a huge mistake not to absorb elementary worldly wisdom…Your life will be enriched – not only financially but in a host of other ways – if you do. – Charlie Munger, Poor Charlie’s Almanack 
  8. Decision Making – Continuously add more building blocks to your knowledge base in order to build more robust mental models
    1. Failures to explain are caused by our failures to describe
    2. Our institutions of higher learning may separate knowledge into categories, but wisdom is what unites them.

What I got out of it

  1. A beautiful book on how to approach being a multidisciplinary thinker as it applies to investing. 

Six Easy Pieces: Essentials of Physics Explained by Its Most Brilliant Teacher by Richard Feynman

Summary

  1. A distillation of some of the key principles that Feynman covers in his lectures

Key Takeaways

  1. Feynman was a theoretical physicist par excellence. Newton had been both experimentalist and theorist in equal measure. Einstein was quite simply contemptuous of experiment, preferring to put his faith in pure thought. Feynman was driven to develop a deep theoretical understanding of nature, but he always remained close to the real and often grubby world of experimental results.
  2. Feynman diagrams are a symbolic but powerfully heuristic way of picturing what is going on when electrons, photons, and other particles interact with each other. These days Feynman diagrams are a routine aid to calculation, but in the early 1950s they marked a startling departure from the traditional way of doing theoretical physics.
  3. The Feynman style can best be described as a mixture of reverence and disrespect for received wisdom. Physics is an exact science, and the existing body of knowledge, while incomplete, can’t simply be shrugged aside. Feynman acquired a formidable grasp of the accepted principles of physics at a very young age, and he chose to work almost entirely on conventional problems. He was not the sort of genius to beaver away in isolation in a backwater of the discipline and to stumble across the profoundly new. His special talent was to approach essentially mainstream topics in an idiosyncratic way. This meant eschewing existing formalisms and developing his own highly intuitive approach. Whereas most theoretical physicists rely on careful mathematical calculation to provide a guide and a crutch to take them into unfamiliar territory, Feynman’s attitude was almost cavalier. You get the impression that he could read nature like a book and simply report on what he found, without the tedium of complex analysis.
  4. Physics is continually linked to other sciences while leaving the reader in no doubt about which is the fundamental discipline.
  5. Right at the beginning of Six Easy Pieces we learn how all physics is rooted in the notion of law—the existence of an ordered universe that can be understood by the application of rational reasoning. However, the laws of physics are not transparent to us in our direct observations of nature.
  6. A great unifying theme among particle physicists has been the role of symmetry and conservation laws in bringing order to the subatomic zoo.
  7. First figure out why you want the students to learn the subject and what you want them to know, and the method will result more or less by common sense.
  8. “The power of instruction is seldom of much efficacy except in those happy dispositions where it is almost superfluous.” (Gibbon)
  9. You might ask why we cannot teach physics by just giving the basic laws on page one and then showing how they work in all possible circumstances, as we do in Euclidean geometry, where we state the axioms and then make all sorts of deductions. (So, not satisfied to learn physics in four years, you want to learn it in four minutes?) We cannot do it in this way for two reasons. First, we do not yet know all the basic laws: there is an expanding frontier of ignorance. Second, the correct statement of the laws of physics involves some very unfamiliar ideas which require advanced mathematics for their description. Therefore, one needs a considerable amount of preparatory training even to learn what the words mean. No, it is not possible to do it that way. We can only do it piece by piece. Each piece, or part, of the whole of nature is always merely an approximation to the complete truth, or the complete truth so far as we know it. In fact, everything we know is only some kind of approximation, because we know that we do not know all the laws as yet. Therefore, things must be learned only to be unlearned again or, more likely, to be corrected. The principle of science, the definition, almost, is the following: The test of all knowledge is experiment. Experiment is the sole judge of scientific “truth.” But what is the source of knowledge? Where do the laws that are to be tested come from? Experiment, itself, helps to produce these laws, in the sense that it gives us hints. But also needed is imagination to create from these hints the great generalizations—to guess at the wonderful, simple, but very strange patterns beneath them all, and then to experiment to check again whether we have made the right guess. This imagining process is so difficult that there is a division of labor in physics: there are theoretical physicists who imagine, deduce, and guess at new laws, but do not experiment; and then there are experimental physicists who experiment, imagine, deduce, and guess.
  10. Now, what should we teach first? Should we teach the correct but unfamiliar law with its strange and difficult conceptual ideas, for example the theory of relativity, four-dimensional space-time, and so on? Or should we first teach the simple “constant-mass” law, which is only approximate, but does not involve such difficult ideas? The first is more exciting, more wonderful, and more fun, but the second is easier to get at first, and is a first step to a real understanding of the first idea. This point arises again and again in teaching physics. At different times we shall have to resolve it in different ways, but at each stage it is worth learning what is now known, how accurate it is, how it fits into everything else, and how it may be changed when we learn more.
  11. If, in some cataclysm, all of scientific knowledge were to be destroyed, and only one sentence passed on to the next generations of creatures, what statement would contain the most information in the fewest words? I believe it is the atomic hypothesis (or the atomic fact, or whatever you wish to call it) that all things are made of atoms—little particles that move around in perpetual motion, attracting each other when they are a little distance apart, but repelling upon being squeezed into one another. In that one sentence, you will see, there is an enormous amount of information about the world, if just a little imagination and thinking are applied.
  12. This means that when we compress a gas slowly, the temperature of the gas increases. So, under slow compression, a gas will increase in temperature, and under slow expansion it will decrease in temperature.
  13. The difference between solids and liquids is, then, that in a solid the atoms are arranged in some kind of an array, called a crystalline array, and they do not have a random position at long distances; the position of the atoms on one side of the crystal is determined by that of other atoms millions of atoms away on the other side of the crystal.
  14. Most simple substances, with the exception of water and type metal, expand upon melting, because the atoms are closely packed in the solid crystal and upon melting need more room to jiggle around, but an open structure collapses, as in the case of water.
  15. As we decrease the temperature, the vibration decreases and decreases until, at absolute zero, there is a minimum amount of vibration that the atoms can have, but not zero. This minimum amount of motion that atoms can have is not enough to melt a substance, with one exception: helium. Helium merely decreases the atomic motions as much as it can, but even at absolute zero there is still enough motion to keep it from freezing. Helium, even at absolute zero, does not freeze, unless the pressure is made so great as to make the atoms squash together. If we increase the pressure, we can make it solidify.
  16. The other processes so far described are called physical processes, but there is no sharp distinction between the two. (Nature does not care what we call it, she just keeps on doing it.)
  17. Carbon attracts oxygen much more than oxygen attracts oxygen or carbon attracts carbon. Therefore in this process the oxygen may arrive with only a little energy, but the oxygen and carbon will snap together with a tremendous vengeance and commotion, and everything near them will pick up the energy. A large amount of motion energy, kinetic energy, is thus generated. This of course is burning; we are getting heat from the combination of oxygen and carbon. The heat is ordinarily in the form of the molecular motion of the hot gas, but in certain circumstances it can be so enormous that it generates light. That is how one gets flames.
  18. if we look at very tiny particles (colloids) in water through an excellent microscope, we see a perpetual jiggling of the particles, which is the result of the bombardment of the atoms. This is called the Brownian motion.
  19. Everything is made of atoms. That is the key hypothesis. The most important hypothesis in all of biology, for example, is that everything that animals do, atoms do. In other words, there is nothing that living things do that cannot be understood from the point of view that they are made of atoms acting according to the laws of physics. This was not known from the beginning: it took some experimenting and theorizing to suggest this hypothesis, but now it is accepted, and it is the most useful theory for producing new ideas in the field of biology.
  20. A few hundred years ago, a method was devised to find partial answers to such questions. Observation, reason, and experiment make up what we call the scientific method.
  21. What do we mean by “understanding” something? We can imagine that this complicated array of moving things which constitutes “the world” is something like a great chess game being played by the gods, and we are observers of the game. We do not know what the rules of the game are; all we are allowed to do is to watch the playing. Of course, if we watch long enough, we may eventually catch on to a few of the rules. The rules of the game are what we mean by fundamental physics…If we know the rules, we consider that we “understand” the world.
  22. At first the phenomena of nature were roughly divided into classes, like heat, electricity, mechanics, magnetism, properties of substances, chemical phenomena, light or optics, x-rays, nuclear physics, gravitation, meson phenomena, etc. However, the aim is to see complete nature as different aspects of one set of phenomena. That is the problem in basic theoretical physics today—to find the laws behind experiment; to amalgamate these classes.
  23. Some historic examples of amalgamation are the following. First, take heat and mechanics. When atoms are in motion, the more motion, the more heat the system contains, and so heat and all temperature effects can be represented by the laws of mechanics. Another tremendous amalgamation was the discovery of the relation between electricity, magnetism, and light, which were found to be different aspects of the same thing, which we call today the electromagnetic field. Another amalgamation is the unification of chemical phenomena, the various properties of various substances, and the behavior of atomic particles, which is in the quantum mechanics of chemistry. The question is, of course, is it going to be possible to amalgamate everything, and merely discover that this world represents different aspects of one thing? Nobody knows. All we know is that as we go along, we find that we can amalgamate pieces, and then we find some pieces that do not fit, and we keep trying to put the jigsaw puzzle together. Whether there are a finite number of pieces, and whether there is even a border to the puzzle, are of course unknown. It will never be known until we finish the picture, if ever. What we wish to do here is to see to what extent this amalgamation process has gone on, and what the situation is at present, in understanding basic phenomena in terms of the smallest set of principles. To express it in a simple manner, what are things made of and how few elements are there?
  24. Because the chemical properties depend upon the electrons on the outside, and in fact only upon how many electrons there are. So the chemical properties of a substance depend only on a number, the number of electrons.
  25. Magnetic influences have to do with charges in relative motion, so magnetic forces and electric forces can really be attributed to one field, as two different aspects of exactly the same thing.
  26. X-rays are nothing but very high-frequency light.
  27. The mechanical rules of “inertia” and “forces” are wrong—Newton’s laws are wrong—in the world of atoms. Instead, it was discovered that things on a small scale behave nothing like things on a large scale. That is what makes physics difficult—and very interesting. It is hard because the way things behave on a small scale is so ”unnatural“; we have no direct experience with it. Here things behave like nothing we know of, so that it is impossible to describe this behavior in any other than analytic ways. It is difficult, and takes a lot of imagination. Quantum mechanics has many aspects. In the first place, the idea that a particle has a definite location and a definite speed is no longer allowed; that is wrong.
  28. there is a rule in quantum mechanics that says that one cannot know both where something is and how fast it is moving.
  29. Another most interesting change in the ideas and philosophy of science brought about by quantum mechanics is this: it is not possible to predict exactly what will happen in any circumstance.
  30. One of the consequences is that things which we used to consider as waves also behave like particles, and particles behave like waves; in fact everything behaves the same way. There is no distinction between a wave and a particle. So quantum mechanics unifies the idea of the field and its waves, and the particles, all into one.
  31. We have been seeking a Mendeléev-type chart for the new particles. One such chart of the new particles was made independently by Gell-Mann in the USA and Nishijima in Japan. The basis of their classification is a new number, like the electric charge, which can be assigned to each particle, called its “strangeness,” S. This number is conserved, like the electric charge, in reactions which take place by nuclear forces.
  32. What is this “zero mass”? The masses given here are the masses of the particles at rest. The fact that a particle has zero mass means, in a way, that it cannot be at rest. A photon is never at rest; it is always moving at 186,000 miles a second.
  33. In fact, there seem to be just four kinds of interaction between particles which, in the order of decreasing strength, are the nuclear force, electrical interactions, the beta-decay interaction, and gravity.
  34. Physics is the most fundamental and all-inclusive of the sciences, and has had a profound effect on all scientific development. In fact, physics is the present-day equivalent of what used to be called natural philosophy, from which most of our modern sciences arose. Students of many fields find themselves studying physics because of the basic role it plays in all phenomena.
  35. Statistical mechanics, then, is the science of the phenomena of heat, or thermodynamics.
  36. There was an interesting early relationship between physics and biology in which biology helped physics in the discovery of the conservation of energy, which was first demonstrated by Mayer in connection with the amount of heat taken in and given out by a living creature.
  37. Thus most chemical reactions do not occur, because there is what is called an activation energy in the way. In order to add an extra atom to our chemical requires that we get it close enough that some rearrangement can occur; then it will stick. But if we cannot give it enough energy to get it close enough, it will not go to completion it will just go partway up the “hill” and back down again.
  38. Physics is of great importance in biology and other sciences for still another reason, that has to do with experimental techniques. In fact, if it were not for the great development of experimental physics, these biochemistry charts would not be known today. The reason is that the most useful tool of all for analyzing this fantastically complex system is to label the atoms which are used in the reactions.
  39. Proteins have a very interesting and simple structure. They are a series, or chain, of different amino acids. There are twenty different amino acids, and they all can combine with each other to form chains in which the backbone is CO-NH, etc. Proteins are nothing but chains of various ones of these twenty amino acids. Each of the amino acids probably serves some special purpose.
  40. If our small minds, for some convenience, divide this glass of wine, this universe, into parts—physics, biology, geology, astronomy, psychology, and so on—remember that nature does not know it! So let us put it all back together, not forgetting ultimately what it is for.
  41. There is a fact, or if you wish, a law, governing all natural phenomena that are known to date. There is no known exception to this law—it is exact so far as we know. The law is called the conservation of energy. It states that there is a certain quantity, which we call energy, that does not change in the manifold changes which nature undergoes.
  42. In order to verify the conservation of energy, we must be careful that we have not put any in or taken any out. Second, the energy has a large number of different forms, and there is a formula for each one. These are gravitational energy, kinetic energy, heat energy, elastic energy, electrical energy, chemical energy, radiant energy, nuclear energy, mass energy. If we total up the formulas for each of these contributions, it will not change except for energy going in and out.
  43. We call the sum of the weights times the heights gravitational potential energy—the energy which an object has because of its relationship in space, relative to the earth.
  44. The general name of energy which has to do with location relative to something else is called potential energy. In this particular case, of course, we call it gravitational potential energy.
  45. Elastic energy is the formula for a spring when it is stretched. How much energy is it? If we let go, the elastic energy, as the spring passes through the equilibrium point, is converted to kinetic energy and it goes back and forth between compressing or stretching the spring and kinetic energy of motion.
  46. other conservation laws there are in physics. There are two other conservation laws which are analogous to the conservation of energy. One is called the conservation of linear momentum. The other is called the conservation of angular momentum.
  47. The laws which govern how much energy is available are called the laws of thermodynamics and involve a concept called entropy for irreversible thermodynamic processes.
  48. What is this law of gravitation? It is that every object in the universe attracts every other object with a force which for any two bodies is proportional to the mass of each and varies inversely as the square of the distance between them. This statement can be expressed mathematically by the equation
  49. Galileo discovered a very remarkable fact about motion, which was essential for understanding these laws. That is the principle of inertia—if something is moving, with nothing touching it and completely undisturbed, it will go on forever, coasting at a uniform speed in a straight line. (Why does it keep on coasting? We do not know, but that is the way it is.) Newton modified this idea, saying that the only way to change the motion of a body is to use force. If the body speeds up, a force has been applied in the direction of motion. On the other hand, if its motion is changed to a new direction, a force has been applied sideways. Newton thus added the idea that a force is needed to change the speed or the direction of motion of a body.
  50. Any great discovery of a new law is useful only if we can take more out than we put in.
  51. Why can we use mathematics to describe nature without a mechanism behind it? No one knows. We have to keep going because we find out more that way.
  52. We conclude the following: The electrons arrive in lumps, like particles, and the probability of arrival of these lumps is distributed like the distribution of intensity of a wave. It is in this sense that an electron behaves “sometimes like a particle and sometimes like a wave.”
  53. “It is impossible to design an apparatus to determine which hole the electron passes through, that will not at the same time disturb the electrons enough to destroy the interference pattern.” If an apparatus is capable of determining which hole the electron goes through, it cannot be so delicate that it does not disturb the pattern in an essential way. No one has ever found (or even thought of) a way around the uncertainty principle. So we must assume that it describes a basic characteristic of nature. The complete theory of quantum mechanics which we now use to describe atoms and, in fact, all matter depends on the correctness of the uncertainty principle.
  54. We would like to emphasize a very important difference between classical and quantum mechanics. We have been talking about the probability that an electron will arrive in a given circumstance. We have implied that in our experimental arrangement (or even in the best possible one) it would be impossible to predict exactly what would happen. We can only predict the odds!

What I got out of it

  1. A fun introductory lesson into some key physics ideas and a great view into Feynman’s thinking process

Genius: The Life and Science of Richard Feynman by James Gleick

Summary

  1. Gleick goes into the fascinating history, personality, and accomplishments of Richard P. Feynman

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Key Takeaways

  1. Feynman was an unusually original thinker, someone with enormous horsepower who wanted to think and build from first principles – sometimes to an exaggerated degree which wasted a lot of his time and lead to many lost hours. However, this was also responsible for his intuitive leaps and orthogonal way of attacking problems
  2. Nature uses only the longest threads to weave her patterns, so each small piece of her fabric reveals the organization of the entire tapestry
  3. Feynman had a deep belief in nature, a skepticism of experts, and a distinct impatience for mediocrity
  4. To Feynman, knowledge was not something used to explain but was pragmatic, something that helped you accomplish things 
  5. He was a true Renaissance man – having had breakthroughs in physics and mathematics and enjoyed playing the drums, picking up women, learning languages, breaking into safes, and more. He was playful, idiosyncratic, independent, and had a chaotic streak in him
  6. If, in some cataclysm, all of scientific knowledge were to be destroyed, and only one sentence passed on to the next generation of creatures, what statement would contain the most information in the fewest words? I believe it is the atomic hypothesis that all things are made of atoms — little particles that move around in perpetual motion, attracting each other when they are a little distance apart, but repelling upon being squeezed into one another. In that one sentence, you will see, there is an enormous amount of information about the world, if just a little imagination and thinking are applied.
  7. Innovation is simply imagination straightjacketed – this was Feynman’s way of thinking through problems. He set barriers, limitations, boundaries on the problem set and then went about solving within this limitations 
  8. Feynman so thoroughly practiced formulas, integrations, and thought experiments that he developed a deep intuition for how they function and apply in the real world. People often joked that his intuition was so spot on that if he wanted to understand how an electron behaves he would simply ask himself, “If I were an electron, how would I behave?”
  9. In high school he had not solved Euclidean geometry problems by tracking proofs through a logical sequence, step by step. He had manipulated the diagrams in his mind: he anchored some points and let others float, imagined some lines as stiff rods and others as stretchable bands, and let the shapes slide until he could see what the result must be. These mental constructs flowed more freely than any real apparatus could. Now, having assimilated a corpus of physical knowledge and mathematical technique, Feynman worked the same way. The lines and vertices floating in the space of his mind now stood for complex symbols and operators. They had a recursive depth; he could focus on them and expand them into more complex expressions, made up of more complex expressions still. He could slide them and rearrange them, anchor fixed points and stretch the space in which they were embedded. Some mental operations required shifts in the frame of reference, reorientations in space and time. The perspective would change from motionlessness to steady motion to acceleration. It was said of Feynman that he had an extraordinary physical intuition, but that alone did not account for his analytic power. He melded together a sense of forces with his knowledge of the algebraic operations that represented them. The calculus, the symbols, the operators had for him almost as tangible a reality as the physical quantities on which they worked. Just as some people see numerals in color in their mind’s eye, Feynman associated colors with the abstract variables of the formulas he understood so intimately. “As I’m talking,” he once said, “I see vague pictures of Bessel functions from Jahnke and Emde’s book, with light tan j’s, slightly violet-bluish n’s, and dark brown x’s flying around. And I wonder what the hell it must look like to the students.
  10. It is not enough to be able to simply repeat, manipulate, and recall mathematical equations. A deep physical intuition of nature and reality is necessary to make the types of leaps that Feynman and Einstein made 
  11. Our knowledge of things is inextricably linked to our language and analogies. Words and phrases that we use cannot be decoupled from our knowledge
  12. Better to have a jumbled bag of tricks than one orthodox tool – imprecise shortcuts and hacks are more effective than rigid planning
  13. Feynman also had tremendous influence in a number of fields outside of particle physics including nanotechnology, genetics, molecular biology, and more. 
  14. Several different times throughout his life, Feynman tried to map his knowledge, the interconnections, and how they influence each other, creating a mental map of his understanding of his world. This would help him understand where his understanding was limited, where connections and interconnections happened, where the edge of the field and new opportunities might be.
  15. Feynman struggled for a long time to figure out which problems to work on. He rarely pursued ideas to their end, even when he was encouraged to do so and the results would likely to lead to breakthrough findings and research papers
  16. Only when you truly understand what an explanation is (not the name, but the nature) can you begin thinking about more subtle questions

What I got out of it

  1. A really enjoyable book which helped me better understand Feynman – how curious, playful, and smart he was but also his temper and his inability to follow through on many papers and experiments. What sticks with me though was how deeply he wanted to understand things – not the name, but the nature. I would also love to see how he mapped his knowledge in his journals. I think this would be a hugely beneficial process to better understand what we truly know, see how things interconnect, where we are lacking knowledge, where the opportunities might lie, etc..

Surely You’re Joking, Mr. Feynman! by Richard Feynman

Summary

  1. Richard Feynman takes us through his fun and at times eccentric life – from art and bongo drums to nuclear physics. Very enjoyable read

If you’d prefer to listen to this article, use the player below.

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Key Takeaways  

  1. Feynman’s life told through his point of view
  2. Worked on the Manhattan project in 1943
  3. Was obsessed with radios as a young kid and figured out how to build and fix broke ones
  4. Had amazing curiosity and solved things by thinking through them before it was taught to him, even things like trigonometry. This series got him in trouble with adults since he wouldn’t simply listen and do – he actually thought and sometimes came up with better ways of doing things but he adults didn’t like that since it wasn’t their way
  5. People don’t learn by understanding, they learn by rote. Their knowledge is so fragile
  6. Put himself in uncomfortable situations a lot of the time because he was trying to figure out a better way to do things or simply learn something new
  7. People often the idea of how they felt but not the exact word or details
  8. Was able to perfectly observe his dreams and control them. He wanted to understand how we were able to see things without any outside stimulation
  9. When somebody is explaining something new to him he always comes up with examples in his mind that would fit the conditions
  10. In life you learn from your mistakes. Don’t make them again. And that’s the end of you
  11. Feynman got really into art and eventually got good enough where he had an agent and was able to sell some of them
  12. Hates arrogant fools more than anything
  13. Sees things so logically and is so curious that it causes problems often and puts him in difficult situations
  14. Wins the Nobel but doesn’t want to deal with all the hassle but ends up accepting it
  15. Becomes incredibly adept at cracking safes
  16. Simply an incredibly curious person who enjoyed solving things and being with other people. Seemed very pragmatic and disliked arrogance of any kind

  What I got out of it  

  1. Feynman’s genuine curiosity and love of life is admirable. Seems like such a carefree person who pursued his curiosity and his desire to learn and teach. He was able to explain things more simply and elegantly than most, learning deeply about things most people simply take for granted or don’t care enough to truly think about.