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  • 发表时间:

    Where does hope come from


    Heisenberg's first paper on quantum mechanics was one of the most profound scientific achievements of all time. Subatomic world is so small, so far away from our concrete experience. How can he formulate a coherent mathematical theory about the subatomic world? 


    In the first paragraph of his paper, he used the word hope twice. In the second paragraph, he stated, "it seems sensible to discard all hope ..." Then he started to present his new ideas. 


    When we are hopeless, don't despair. Hope comes from hopeless. A great dawn is waiting for us tomorrow. 



  • 发表时间:

    How solar cells work?

    First, we will look at hydro dams. Hydro dams are gigantic solar cells.

    The sun shines on water. Some water molecules absorb photons and gain enough energy to jump out of water. They rise to the sky, fall down as rain, and some of them end up in a lake circled by the dam. Then water flows down the dam to generate electricity.

    Solar cells are diodes. They contain PN junctions, which are energy dams.

    The sun shines on solar cells. Some electrons absorb photons and gain enough energy to jump over the dam, or the PN junction. Then those high energy electrons flow over the wires to form electric currents, doing all kinds of works.

    Semiconductors do all sorts of communication works. Solar cells generate electricity from light. LED generate light from electricity. All these devices are based on silicon. All are based on PN junction. 

    In periodic table, silicon is in the same group of carbon, the backbone of life. It is right below carbon. In constructing PN junction, the P (positive) junction uses B, left to the group of carbon and silicon, the N (negative) junction uses P, right to the group of carbon and silicon. So B is in group three. Silicon is in group four. P is in group five. 



    H







     Li

    Be

    B

    C

    N

    O

    F

    Na

    Mg

    Al

    Si

    P

    S

    Cl



  • 发表时间:

    Why LED lights are more efficient?

    There is a big stone. You want it to possess some energy. What you can do? 

    You can push it, push it really hard to make it moving. It gains some speed. But not very high. Or you can put it by a cliff. Give it a gentle push. The stone will fall, fall faster and faster. When it reaches the bottom of the cliff, it will release a big impact.

    For regular lights, electric voltage pushes electrons, pushes them really hard. Electrons gain some speed. But most of them are not very high, not high enough to generate bright light. Most of the energy is released in feeble invisible infrared light. 

    Or you can set up a cliff with LED (Light Emitting Diode). An LED contains a PN junction, which is really an energy cliff, or more accurately an energy dam. Electric voltage gently pushes electrons through the PN junction, or the dam. Electrons fall hard through the dam. When they land at the bottom, they release a big impact in the form of high energy photons.  That is why LED lights are more efficient than regular lights.

    Solar cells work in a similar way. They are also diodes containing PN junctions.


  • 发表时间:

    On inequality

    1. Inequality in nature

    The water level inside a dam is higher than that outside the dam. The difference of water levels drives the movement of electricity generators to produce electricity. The air pressure inside an engine is higher than that outside the engine. The difference of air pressure propels the movement of engine. The biggest source of energy on the earth is from the sun. The temperature on the sun is much higher than the temperature on the earth. The difference in temperature drives much of the atmosphere movement, ocean currents, rainfalls, and photosynthesis on the earth. Without inequality, the world is a dead place.

    From thermodynamic theory, the efficiency of an engine is determined by the difference of temperature inside and outside engine. The higher the temperature differential, the more efficient an engine becomes. This is a general principle. The efficiency of a dam to generate electricity is determined by the height of the dam. The higher the dam, the more electricity can be generated. The efficiency of transmitting electricity over long distance is determined by the voltage differential. The higher the voltage differential, the less energy loss during transmission.

    At the same time, systems with higher differential require higher cost to build. An engine that can withstand higher temperature and pressure is more expensive to build. So are higher dams and high voltage transmission systems. Systems with higher differentials, when they fail, can cause greater damage. A higher pressure engine causes greater damage when they explode. A higher dam causes greater flood when it collapses. A nuclear power plant, which uses high density nuclear energy as fuel, can cause great environmental damage when accidents occur.

    Because of the need to maintain differential, systems generally have barriers to separate inside from outside. Engines have combustion chambers that separate inside from outside. Dams are constructed to separate inside from outside. Cells have membranes, where concentration of many materials and the electric potentials are different inside and outside. A system maintaining higher differential need to withstand greater pressure. It is more rigidly built. This is true for engines, dams, or transmission lines.

    2. Inequality in human societies

    There is a strong parallel in human societies. Human societies everywhere are unequal. In businesses, there are supervisors and subordinates. In academics, military and government, there are different ranks. There are rich countries and poor countries.

    Greater inequality often means greater profits. Companies can raise prices when they have great competitive edge. Universities that are more exclusive can charge higher tuitions. Companies often move production facilities to lower wage places to increase profit margins.

    At the same time, systems with higher differentials with respect to the environment are more costly to maintain. At the US Mexico border, US side maintains an expensive border screening system while people can enter Mexico freely. An affluent society requires extensive education system to maintain its social structures.

    For the designers of a system, the choice of the level of inequality depends on the tradeoff between marginal efficiency and maintenance costs. In North America, electric voltage in residential areas is 110 V while in most other parts of the world, the electric voltage is 220 V. To carry the same amount of electric energy in a 110 V system requires much thicker wire than in a 220 V system. However, when accidents occur, 110 V causes less shock than 220 V. In a system with abundant natural resources, such as North America, we often choose less resource efficient but safer options. In systems with scarce natural resources, we often choose more resource efficient but riskier options.

    There is a parallel in social systems. In a social system that controls more resource, its internal inequality is often low. However, such system can utilize abundant resources as “energy slaves” (Nikiforuk 2012) or impose inequality on other weaker social systems. In a social system that controls less resource, its internal inequality is often high. In such system, efficiency is very high for the elites, the designers of the system. However, such systems also have a higher probability of experiencing violent revolution. When factories are located in wealthy countries, much resource is used to control pollution. This lowers the ratio of output over resource input. But when factories are moved to poor countries, where local population has little political power, little resource is allocated to control pollution. This increases the ratio of output over resource input. Pollution is the reduction of chemical potential. Increasing pollution is the increase of inequality in chemical potential. By increasing inequality, the designers of the system gain higher efficiency and obtain cheaper products as a result.

    It requires higher fixed cost to maintain a more unequal society. Dominant parties of a society do not necessarily hope to increase inequality all the time. When the British Empire was expanding rapidly in the 19th century, it abolished slavery, a more extreme form of inequality. By adopting less unequal social systems, Britain was able to maintain and expand a huge empire with relatively little cost and huge profit. The inequality of a system also depends on how long the dominant parties expect the system to last. When we go fishing, we hope to have some inequality over fish. We use a fishing line to hook fish. However, if the general public is allowed to use fishing nets in rivers, lakes and oceans, fish population will decline rapidly in a very short period of time. For an unequal system to last, the level of inequality cannot be too extreme. This applies both in nature and in human societies. When the dominant parties expect the system to end soon, the inequality of the social system tends to increase so that dominant parties can extract more profits while the system lasts.

    In popular terms, the inequality in gravitational potential, chemical potential, electric potential and other potentials is called energy. From thermodynamic theory, inequality in potential, or energy is the driving force in the nature. It is also a destructive force. We all need energy provided by oxygen. At the same time, our body produces many antioxidants to prevent oxygen from reacting with and destroying our tissues. Sugar is a vital energy our body needs. But too much sugar in our blood system, and in cells, will damage our health. When we cannot maintain a low level of sugar in our blood system, we get diabetes.

    Human societies depend very much on high energy input. However, we carefully regulate the energy sources. “Playing with fire” is always considered dangerous. Whenever possible, systems with high gradient, or high inequality are carefully regulated. They are contained in isolated or remote places. Furnaces are usually located in basements. Electric generators are usually placed very far from residential areas.

    3. Inequality in public discussion

    Inequality is everywhere. If so, why most people, especially the richest and the most powerful, claim to fight for equality? This is because most people are at the lower end of the society. Today the richest person has more than a hundred billion asset. Half in the middle is fifty billion. Only few people have more than fifty billion asset. Most people have far less than a billion asset. This is why almost all the public announcements, whose main listeners have very little asset, promote equality. People promoting equality gain higher moral grounds than others. And people with higher moral grounds gain higher social status.

    Almost everything we do is to increase or maintain inequality. However, we avoid the term inequality. We try to stand out, or to be outstanding. We want to obtain and maintain competitive edge. We try to gain knowledge premium to generate higher profit. We produce patents to create monopoly. Our gods and political systems are superior to others.



    水坝越高,发电的效率就越高。同样,电压越高,输电过程中损失越小,效率越高。但是水坝越高,造价也越高。同样,输电线路的电压越高,变电站的造价也越高。社会也是一样,工人的工资越低,资本的效率越高,但同时,工人的不满也越多,维护社会稳定的成本也越高。中国这几十年经济持续高速发展,主要得益于户籍制度,农民工没有多少权力,也没有多少选择,尽管中国对外贸易长期大量顺差,农民工的收入增加很慢,这就保证了中国企业长期的竞争力。但是,大多数底层人士对中国巨大的贫富差距非常不满,使得维稳的成本很高。在世界范围内,美国是唯一的超级大国,享有很多特权,但美国必须在军事上大量花销,以维持其超级大国的地位。


    并非所有时候,人们都会追求短期的高效率。当高压电输送到用户的时候,会把电压降下来,世界上大部分地方是 220 伏,但北美是 110 伏。其中一个原因,是北美资源丰富,所以对效率要求低,对安全要求高。十九世纪,当英国快速扩张,殖民地不断增加的时候,废除了奴隶制。这样,就减少了统治者和被统治者的矛盾,使英国人可以统治更多的地方。香港曾是英国的殖民地,很多港人依然怀念过去的时光。

    任何一个生命系统和和社会系统,都是物理系统的一部分,都服从物理规律。而某些物理系统之所以能成为生命系统和社会系统,在于它们能够自然环境中的不平等,或者梯度。水电站利用了大坝两侧,水位的梯度。植物的光合作用利用了太阳温度和地球温度的梯度。

    卡诺给出了系统的梯度与有用功之间的关系,热量转化为有用功的效率是 1-  T1/T2, T1, T2 是系统两侧的温度,如果两侧的温度相等,系统不能输出任何有用功,两侧的温差越大,转化的效率越高。柴油的燃点高于汽油,所以柴油机的效率高于汽油机,但柴油机的造价也高于汽油机,因为需要承受更高的温度和压力。

    当一个系统,摄取的总资源长期高于消耗的总资源,这个系统就能长期生存下去,否则,就会逐渐衰亡。一个生物如此,一个投资项目如此,一个社会也如此。


    附录:温差与热量转化为有用功的效率的推导


    设想一个内燃机,汽缸内的高温是T2,环境的低温是T1,内燃机对外做功为W,环境和汽缸内的熵值变化分别为 dS1 和 dS2, 汽缸内向外输送的热量是q,由热力学第一定律,我们得到

        -T2dS2 = q = T1dS1 + W, 

    所以

         W = -T2dS2 - T1dS1,

    从热力学第二定律,我们得到

        dS1 + dS2 >= 0

    或者

        dS1 >= -dS2

    所以

        W <= -T2dS2 + T1dS2 = (T1-T2)dS2

    从上面,

        dS2 = -q/T2

    因而

        W <= (T1-T2)(-q/T2) = (1- T1/T2)q

    所以,热功转换效率

       W/q <= 1- T1/T2



  • 发表时间:

    The Big Short

    “Since I was a child, I feel more comfortable being alone.” Michael Burry, the main character in the movie, stated. If he prefers to be alone, how he can succeed in the investment business, or in any business?

    A person alone has a lot of time. He is also under less pressure to conform. He did his own homework, his own analysis and formed his own opinion. For example, he didn’t rely on professional rating agencies to value mortgage bonds. He actually looked into individual mortgage contracts himself. Moody and S&P rated those bonds AAA. But he knows a lot of those mortgages will default. His inability to socialize makes it easy for him to do his own work and to form his own opinion. As a result, he produced stellar investment performance. Others seek his professional service. He doesn’t have to socialize with others.

    The Big Short is about a bunch of weirdos who foresaw the coming collapse of the financial markets in 2007. They short the market early on. That’s why the movie is called The Big Short.

    “I may be early. But I am not wrong.” Michael Burry defended his investment decisions when questioned by Lawrence, a large investor. Lawrence replied, “They are the same.” Indeed, being early or being wrong, you get the same result. 

    In financial markets, you could be one or two years early. You will be redeemed in one or two years. Major social trends may never reverse, until the society collapses. That might be several generations away. If your ideas differ from the mainstream, you short the society. You had better lie low and try to avoid conflict and confrontation as much as possible.


  • 发表时间:

    Timeline by Michael Crichton

    When your ideas are against the mainstream, when you are not happy about the direction of the society you live in, there are few outlets for your ideas. What you can do? Write attractive stories! Michael Crichton is such a story writer.

    Timeline is a science fiction novel by Michael Crichton. In the novel, some graduate students from Yale were sent, via a quantum system, whatever that is, to medieval France when violent fighting was very common. When running for his life, Chris, one of the graduate students, somehow thinks of the seminar room at Yale where they endlessly debated. He reflected,

    The academics arguments consist of nothing but thin air and hot air. Their empty debates could never be resolved. Yet there is so much intensity, so much passion in these debates.  ... However frightened he was on this night, it was entirely real and in some way reassuring, even exhilarating. (Roughly at 2:09 of part 2 of the audiobook)

    A short time later, when he examined his serious wounds, he pondered, 

    The pain might make him gasp for breath. But the pain didn’t matter. He just felt glad to be alive and facing another day. His familiar complaints, cowered uncertainties seem suddenly irrelevant. In their place, he discovered some source of boundless energy and almost aggressive vitality he could not recall he had ever experienced before. He felt flowing in his body a kind of heat. The world around him seemed more vivid, more sensuous than he could remember before. To Chris, the great dawn took on a pristine beauty. The cool damp air bore a fragrance of wet grass and damp earth. The stone against his back supported him. Even the pain was useful because it burned away all unnecessary feelings. He felt stripped down, alert and ready for anything. This is a different world, with different rules. And for the first time, he was in it, totally in it. (2:30)


    Kate gave some food to a poor old man. The old man grabbed her. He and his fellow bandits tried to rob her. Chris came up to save her. Later Chris asked what happened. Kate said she was trying to help a poor man. Chris said this only happened in fairy tales. In real life, if you help a poor man, you will be robbed and killed. (4:47)

    Andre chose to stay in medieval time and didn’t return to the modern world. His dying word was, “I have children, and a good life.” (7:30)



  • 发表时间:

    Money: Whence it came, Where it went (Quotes and comments)


    John K. Galbraith

     

    The study of money, above all other fields in economics, is one in which complexity is used to disguise truth or to evade truth, not to reveal it.”  P.5

    Comment: In any research, complexity is used to disguise or evade truth, not to reveal it.


    The message from the Americas was not one that brought uniform joy. In Spain the new wealth led also to a bidding up of wages; there wages seem to have keep pace,more or less, with prices. Elsewhere in Europe they lagged far behind, differences in population growth being a possible influence. (P 12)

     

    Not for the last time — and the probably not for the first — inflation had a profound effect on the distribution of income, with a particular tendency to punish most those who had least. The loss of those who receive the lagging wages was in turn the gain of those who paid them and to receive the high and increase in prices. The result was high profits, and the further result was a general quickening of commercial and, in more elementary manifestation, industrial capitalism. Historians have for long talked, often with more grandeur than personal comprehension, of how the American treasure financed, lubricated, stimulated or otherwise enhanced the early development of European capitalism. In one view it was the gold and silver per se that nurtured that capitalism. In fact, it was not the metal but its consequences, and these were not at all mysterious. The high prices and low wages meant high profits. From high profits came high savings and a strong incentive to their investment. additionally the rising prices made it easy to make money, to the natural reward of shrewd trading or efficient manufacture was added the gain, with the passage of time, from the ability to sell the same thing for more. (P. 13)

     

    War, it is well to recall, was an important occupation of the age, with a major claim on public revenue. (Max Weber estimated that in this period about 70 percent of Spanish revenues and around two thirds of the revenues of other European countries were so employe.). P 15

     

    Then, as since, it was uncertain what made a man a monetary expert. P. 36

     

    Comment: It is always uncertain what makes a man an expert. Don’t be intimidated by a so called expert.

     

     

    By far the most memorable participant in this debate was a London stockbroker of Jewish provenance who, unknown to himself or anyone else, was, by this discussion, launching one of the most famous careers in economic thought. Some would later count him as the greatest of all economists. This was David Ricardo.   P. 37

     

    Comment: When we have ideas about something, we should join the discussion and write them down, we should develop them into a concrete product. It is through discussion that we clarify our thinking. It is through producing a poem, a video, an app that we develop our skills. It is by solving math problems that we become brilliant at thinking. If we let ourselves be suppressed, our seeds of ideas will not grow into great trees.

     

    Few phrases have ever been endowed with such mystery as open market operations, the bank rate, the rediscount rate. This is because economists and bankers have been proud of their access to knowledge that even the most percipient of other citizens believe beyond their intelligence. Open market operations are the sale of securities just mentioned by the central bank which removes the loanable cash or reserves from the commercial or ordinary banks. The bank rate and the rediscount rate are the same; they are what prevent the banks from too painlessly recouping their cash by borrowing from the central bank. This is it.  P 40.

     

    Paper money ... was a substitute for taxation. P. 46

     

    On the whole, older communities are less inclined to monetary experiments than newer ones.  P. 56

     

    Comment: On the whole, older communities are less inclined to any experiments than newer ones. 



    The Congress was without direct power of taxation; one of its first acts was to authorize a note. Issue. More states now authorized more notes. It was by these notes that the American Revolution was financed. ... Overwhelmingly the Revolution was paid for with paper money.  P. 59



    Thus the United States came into existence on a full tide not of inflation but of hyper-inflation— the kind of inflation that ends only in the money becoming worthless. What is certain, however, is the absence of any alternative.   ...  It was not a thought to which later historians were attracted. As in the case of the colonial paper, the influential historians were men for whom hard money and the gold standard were matters not of economics but of morality. The exigent needs of a new country were secondary to what was right. P. 60



    In the accepted, and it must be added, far from inspiring view of the monetary history of the United States, the years after 1832 were deplorable. Free banking, the resulting bank failures, then greenbacks, agitation for more greenbacks and the pressure, partly successful, for the coinage of cheap silver combined with the recurrent panic to make the financial system of the United States, as Andrew Carnegie held, “the worst in the civilized world”.


    yet not everything could have been wrong. For those who spoke most despairingly of the monetary aberrations of the United States in the last century spoke always admirably  and sometimes ecstatically of the nation’s economic development. Nothing like it had ever been seen before. One of two things must be true. The monetary arrangements must have some redeeming aspect. Or else they were exceptionally unimportant.

     

    In a more serious and slightly deeper view, the hundred years from 1832 on were ones of basic compromise. There existed, in effect, a dual monetary system. Each of the parts fitted the needs or predilections of the part of the country or economy that is served. Between the parts was an uneasy coexistence interrupted by occasional conflicts. Peace was based, in the main, on the inability of each side to destroy the system favored by the other. On each side this incapacity was the source of much righteous regret.

     

    For the growing financial, trading and creditor community, mostly of the East but as always with the passing decades extending its influence west and south, the arrangement provided a basic hard money – gold and silver. And for this community, first under state, then under Federal regulation, there were increasingly reliable banks …

     

    For the new parts of the country as they open up, there was the right to create banks at will and therewith the notes and deposits that results from their loans. No central bank tested the ability of these banks to redeem their notes; while there were state regulations specifying the cash to be held in reserve against notes and deposits, these were enforced with a light and gracious hand.  …

     

    It was an arrangement which reputable bankers and merchants in the East viewed with extreme distaste. … Men of economic wisdom, then as later expressing the views of the reputable business community, spoke of the anarchy of unstable banking. And they explained that the settlers, in their urge to get hold of bank notes and with their primitive view of economics, were confusing money with capital. The men of wisdom missed the point.

     

    The anarchy served the frontier far better than a more orderly system that kept a tight hand on credit could have done. And no naive confusion of capital and money was involved. For the settler the notes he got from the bank were capital, for they got him capital. It is not often that people misjudge their pecuniary interest on a large scale over a long time. ... what is called sound economics is very often what mirrors the needs of the respectably affluent. P. 86



    In the United States one important tradition in economics runs less to conservatism than to a comfortable conformity.  ... the desire of numerous Harvard faculty members of much professional distinction to commute from home, wife and issue in an amiable suburb to office, computer and classroom with no disturbance or dismay from controversy, criticism or even unsettling thought. This preference for comfort excludes evidence when it is in conflict with convenience. ... Academic life would not, for certain, be improved if all its participants shared a compulsion to shake or change the world. P. 118

     

    The effect of both corporate concentration and union strength was to make radically more unreliable the adjustments which were assumed to sustain Say’s Law and the full employment equilibrium. P. 221

     

    “Hitler already found how to cure unemployment before Keynes had finished explaining why it occurred.” ... Thus the effect of The General Theory was to legitimize ideas that were in circulation. What had been the aberration of cranks and crackpots became now respectable scholarly discussion. To suggest that there might be oversaving now no longer cost a man his degree or, necessarily, his promotion. That the proper remedy for oversaving was public spending financed by borrowing was henceforth a fit topic for discussion — although it continued to provoke bitter rebuke. ...

     

    Keynes was taken up, in the main, by younger scholars. Economists are economical, among other things, of ideas; most make those of their those of their graduate days do for a lifetime. So change comes not from men and women changing their minds but from the change from one generation to the next. P. 227

     

    The difficulty was that market power and price administration were not a problem of a few firms; they were pervasive in the American economy. So the remedy required a complete restructuring of that economy. … And not many in the New Deal were willing to propose the logical companion step, which was to disintegrate the trade unions.  P. 229

     

     

     

     

     

     

     

     





  • 发表时间:

    Money supply and wealth distribution 

    A person prints a million dollar counterfeit money. If he is not busted, he will own a million dollar wealth. A person prints a million dollar real money. He can’t be busted. He will own a million dollar wealth. How much money is out there? The following are the ratio of money supply (M2) to GDP in some countries.

    US: 0.7,   Canada:  0.7, France:  1,  Korea: 1.6,  Japan: 1.9, China: 2.2. 

    Among these countries, US and Canada have the least amount of money related to their economic output, China has the greatest amount of money issued. US doesn’t exactly run a tight ship. It practices quantitative easing. But for the sake of simplicity, we assume the amount of money issued by US, 70% of GDP, is just enough for economic activities. The rest are profits for money issuance agencies, such as central banks.

    In China, money supply is 2.2 times of the amount of GDP. 2.2 - 0.7 = 1.5. This indicates the surplus money is 1.5/2.2, or about 2/3, of the total money supply, which is 182 trillion Chinese Yuan. So the monetary wealth owned by the issuing agencies is roughly 120 trillion Yuan. Suppose China is controlled by about one thousand families. These families have direct or indirect access to the money issued. On average, each family would possess 120/1000 = 0.12 trillion or 120 billion Yuan of wealth.

    There is no official statistics of wealth owned by the most prominent Chinese families. Last time, a minister of the Chinese government fell out of favor. It was reported that his family has more than 100 billion asset. So the estimated number of 120 billion Yuan (over 10 billion USD) per family is probably close.

    Where is the vast amount of wealth from China originated? On average, Chinese workers work 2200 hours a year, compared with 1610 hours by US workers. 


  • 发表时间:

    Duo and double means two


    Doubt: When there are two possibilities, you are in doubt.

    Dubious: When one works for two sides, he is dubious.

    Duel: When two persons, two companies or two countries are contending for dominance, the outcome will be determined by a deadly duel. 

    Duplicity: Duplicity is double dealing. It is cheating.