(2004-02-06)
Academician Chu Diwen,1born on February 28th, 937, was born in Taicang County, Jiangsu Province. Major in applied physics (atomic physics); 1970 graduated from the university of rochester with a bachelor's degree in mathematics and a bachelor's degree in physics; 1976 received a doctorate in physics from the University of California, Berkeley. The doctoral thesis is "Prohibition of Atomic Thallium, Measurement of Transition M 1, 62P 1/2- 72P 1/2", and the doctoral supervisor is Professor Cummins. Currently teaching physics and applied physics at Stanford University.
award-winning work
The method of cool and trapping atom by laser is developed.
Influence on scientific research
Similar techniques can also be used to study the mechanical properties of DNA or other polymer chains. When he was still in Bell Laboratories, he invented a kind of "optical tweezers", which was a bit like the tail beam in Star Wars. He can manipulate tiny substances with lasers, including bacteria, DNA and so on. They also studied the contraction of muscle protein cells called "molecular motors". Of course, this technology can also manipulate substances in cells or treat rare elements or radioactive elements in closed containers without destroying cell membranes.
Samuel Chao Chung Ting
(2004-02-06)
Ding Zhaozhong's ancestral home is Rizhao County; 1936 was born in Ann Arbor, Michigan, USA; His father is Ding and his mother is Wang Juanying. He studied in a middle school in Taipei, studied undergraduate and graduate students at the University of Michigan, and received his doctorate from 1962. I have been teaching at MIT since 1967. Professor Ding has made many outstanding contributions to particle physics. The most famous one is that 1974 discovered the J particle, which led the new direction of particle physics, and 1976 won the Nobel Prize in physics. In addition, his research on the accuracy of quantum electrodynamics, the properties of leptons, the properties of vector particles, the phenomenon of gluon injection and the interference of Z-γ are all very important contributions. In recent years, Professor Ding set up and led the experimental group to actively build L3 detector, which will be tested on the LEP accelerator of CERN from 1988. This is a great plan, which has mobilized more than 400 experimental physicists around the world, and the construction cost of the detector will exceed 1 100 million US dollars. Professor Ding is one of the most outstanding contemporary experimental physicists. His work is characterized by clear and decisive direction and careful planning.
award-winning work
A new kind of heavy elementary particle, J/ψ particle (now called J particle), was discovered.
Yang Zhenning
(2004-02-06)
Hefei County, Anhui Province, was born on August 22nd, 11th year of the Republic of China. 1928 attended Xiamen Primary School, 1933 attended Chongde Middle School in Beiping, and 1938 attended Kunwan Middle School in Kunming. He was admitted to the Department of Chemistry of National Southwest Associated University, where Tsinghua, Peking University and Nankai were merged, and later changed to the Department of Physics. 1942 graduated from National Southwest Associated University, 1944 graduated from National Southwest Associated University Research Institute, 1945 went to the United States after teaching in the middle school attached to National Southwest Associated University, 1948 completed his Ph.D. from the University of Chicago in the summer, 1949 studied at Princeton University in the autumn, /kloc-0 won the nobel prize in physics in 1957, and/kloc-0 was elected as an academician of academia sinica in 1958. at the invitation of thor, president of the state university of new york, he planned to set up a research department at stony brook, and left Princeton in 1966 to take charge of the institute of physics at the state university of new York at stony brook.
1957, in cooperation with Li Zhengdao, he overthrew Einstein's "parity conservation law" and won the Nobel Prize in physics. Their contributions are highly praised and considered as one of the milestones in physics. Although he has become an American citizen, he is also a "Chinese-American" and China people are proud of news. Yang is also proud of the China culture and education he received in Tao Wei. When they accepted the Nobel Prize that year, he delivered a speech on their behalf. In the last paragraph, he said, "I am deeply aware of the fact that, broadly speaking, I am the product of China culture and western culture, and the product of harmony and conflict between the two sides. I want to say that I am proud of my China tradition, and I am also committed to modernization. After teaching 17 years, Yang left Princeton University on 1966 and went to the State University of New York at Stony Brook to take charge of the research work of the Institute of Theoretical Physics. He thought he "walked out of the ivory tower" and started over. The scientific community is expecting and optimistic about the possibility of his winning the Nobel Prize again. Mrs. Yang was born in a famous family, worked for General Du, specialized in literature, and had high attainments in both Chinese and English. She has taught English in Taiwan Province Province and Chinese in the State University of New York at Stony Brook. She has three children, the eldest is Yang Guangnuo, a computer engineer, the second is Yang Guangyu, a chemist, and Yang Youli is a doctor.
award-winning work
It is found that parity is not conserved in weak interaction: if parity conservation is not established in weak interaction, parity concept cannot be used in the decay process of θ and τ particles, so θ and τ particles can be considered as the same particle.
Influence on scientific research
The theory of Yang Zhenning and Li Zhengdao overthrew the law of parity conservation that existed in physics for 30 years. This discovery enabled the Swedish Academy of Royal Science to immediately award the Nobel Prize in Physics in 1957 to Dr. Yang Zhenning and Dr. Li Zhengdao, because they corrected the serious mistakes made by scientists in the past, and even started the research on some laws of the "weak exchange" of elementary particles, which made mankind's understanding of the inner layer of material structure take a big step forward.
Henry cavendish.
(2004-02-06)
Cavendish is an English physicist and chemist. 173 1 year 1 month 1 was born in Nice, France. 1749 was admitted to Cambridge university, 1753 studied in Paris before graduation. After that, he returned to live in London and did a lot of electrical and chemical research in his father's laboratory. 1760 was elected as a member of the royal society. 1803 was elected as a foreign academician of French Academy of Sciences. Cavendish devoted his whole life to scientific research and engaged in experimental research for 50 years. He was withdrawn and rarely contacted with the outside world. Cavendish's main contributions are as follows: 178 1 year produces hydrogen for the first time, and its properties are studied. Experiments show that it produces water after burning. However, it is a great pity that he once mistook the discovered hydrogen for phlogiston. 1785, cavendish discovered the existence of inert gas by introducing electric sparks into the air. He has done many successful experimental studies in chemistry, heat, electricity and gravity, but rarely published them. A century later, Maxwell sorted out his experimental papers and published a book entitled "Dear Henry cavendish's Electrical Research" in 1879. Only then did people know that Cavendish had done many electrical experiments. Maxwell said: "These papers prove that Cavendish foresaw almost all the great facts in electricity, which became famous in the scientific community through Coulomb and the works of French philosophers."
Long before Coulomb, Cavendish had studied the charge distribution on the conductor. 1777, he reported to the Royal Society: "The attraction and repulsion of electricity are probably inversely proportional to the square of the distance between charges. If so, almost all the excess electricity in the object is accumulated near the surface of the object, and the electricity is tightly pressed together, and the rest of the object is in a neutral state. " He also proved the force between charges through experiments. He proved through experiments that before Faraday, the capacitance of a capacitor depended on the substance between two plates. He first established the concept of potential, pointing out that the potential at both ends of a conductor is directly proportional to the current passing through it (Ohm's law is established in 1827). It was impossible to measure the current intensity at that time. It is said that he bravely used his body as a measuring instrument to estimate the current intensity by feeling the electric vibration from his fingers to his arms.
One of Cavendish's great contributions was to complete the torsion balance experiment for measuring gravity in 1798, which was later called the Cavendish experiment. He improved the torsion balance designed by the British mechanic Michel (John Lin Kewei, 1724 ~ 1793), added a small plane mirror to its suspension system, and used a telescope for remote operation and measurement outdoors, thus preventing air disturbance (there was no vacuum equipment at that time). He hung a 6-foot-long wooden pole with 39-inch silver-plated copper wire, fixed a small shot with a diameter of 2 inches at each end of the wooden pole, attracted them with two large fixed shot with a diameter of 12 inch, measured the swing period caused by gravity between the shots, and calculated the gravity of the two shots, and then calculated the mass and density of the earth from the calculated gravity. He calculated that the density of the earth is 5.48 1 times that of water (the modern value of the density of the earth is 5.5 17g/cm3), from which the value of the gravitational constant g can be calculated as 6.754×10-1N2/kg2 (. British physicist J.H. Poynting once commented on this experiment: "It initiated a new era of weak force measurement".
Cavendish published a paper on artificial air in 1766, and won the Copley Medal of the Royal Society. He made pure oxygen and determined the contents of oxygen and nitrogen in the air, which proved that water is not an element but a compound. He is called "Newton in chemistry".
Cavendish worked in his own laboratory all his life and was called "the richest scholar and the most learned millionaire". Cavendish died on 18 10 on February 24th.
Later, his descendants' relative, S.C. cavendish, Duke of Devon VIII, donated a fortune to Cambridge University on 187 1 to build a laboratory. It was originally a teaching laboratory of physics department named after H. Cavendish, and later it was expanded into a research and education center including the whole physics department, and was named after the whole Cavendish family. The center pays attention to independent, systematic and group pioneering experiments and theoretical exploration, in which the key equipment advocates independent control. In the past century, the number of Nobel Prize winners trained by Cavendish Laboratory has reached 26. Maxwell, Rayleigh, J.J. Tang Musun, Rutherford and others all presided over this laboratory.
degree kelvin
(2004-02-06)
Kelvin is a famous British physicist and inventor, formerly known as W. Tang Musun. He is one of the greatest figures in this century, a great mathematical physicist and electrician. He is regarded as the first physicist in the British Empire and is appreciated by other countries in the world. He won all possible honors in his life. And all this is worthy of him, and he gained it through practical efforts in his long life. These efforts not only made him famous and rich, but also won a wide reputation.
1824 Kelvin was born in Belfast, Ireland on June 26th. He was smart and studious since he was a child, and he entered Glasgow University Preparatory School at the age of 10. /kloc-at the age of 0/7, Zeng Lizhi said that "where science leads, there will be constant climbing". 1845 graduated from Cambridge University, and won the second prize of Langer Prize and the first prize of Smith Prize during the university. After graduation, he went to Paris and worked with physicist and chemist V. Regnaud for a year. 1846 was employed as a professor of natural philosophy (another name for physics at that time) at the University of Glasgow for 53 years. Due to the meritorious service of installing the first Atlantic submarine cable, the British government knighted him in 1866 and promoted him to Lord Kelvin in 1892, hence the name Kelvin. 1890 ~ 1895 chairman of the royal society of London. 1877 was elected as an academician of the French Academy of Sciences. 1904 was the president of Glasgow University until 1907+ 17 died in Neshall, Scotland in February.
Kelvin's research has a wide range, and he has made contributions in the fields of heat, electromagnetism, fluid mechanics, optics, geophysics, mathematics and engineering applications. He published more than 600 papers in his life and obtained 70 kinds of invention patents. He enjoyed a high reputation in the scientific community at that time and was highly respected by scientists and scientific groups in Britain, Europe and America. His research on heat, electromagnetism and its engineering application is the best.
Kelvin is one of the main founders of thermodynamics and has made a series of great contributions in the development of thermodynamics. According to the theories of Gay-Lussac, Kano and clapper Long, he founded the thermodynamic temperature scale in 1848. He pointed out: "The characteristic of this temperature scale is that it is completely independent of the physical properties of any special substance." This is the standard temperature scale in modern science. He is one of the two main founders of the second law of thermodynamics (the other is Clausius). In 185 1, he put forward the second law of thermodynamics: "It is impossible to absorb heat from a single heat source and make it completely useful without other influences." This is the accepted standard expression of the second law of thermodynamics. It is also pointed out that if this law is not established, it must be admitted that there can be a perpetual motion machine, which can obtain mechanical work indefinitely by cooling seawater or soil, which is the so-called second perpetual motion machine. He asserted from the second law of thermodynamics that energy dissipation is a universal trend. 1852 cooperated with Joule to further study the internal energy of gas, improved the free expansion experiment of Joule gas, conducted the porous plug experiment of gas expansion, and found Joule-Thomson effect, that is, the temperature change phenomenon caused by adiabatic expansion of gas through porous plug. This discovery has become one of the main methods to obtain low temperature and is widely used in low temperature technology. In 1856, he predicted a new thermoelectric effect in theory, that is, when current flows through a conductor with uneven temperature, the conductor will absorb or release some heat (called Tang Musun heat) in addition to generating irreversible Joule heat. This phenomenon was later called Thomson effect.
In electricity, Tang Musun studied all kinds of problems skillfully, from static electricity to transient current. He revealed the similarity between Fourier heat conduction theory and potential theory, discussed the concept of Faraday's electric action propagation, and analyzed the oscillating circuit and its alternating current. His article influenced Maxwell, and Maxwell asked him for advice, hoping to study the same subject with him and gave him a high evaluation.
Kelvin has made outstanding achievements in electromagnetic theory and engineering application. 1848, he invented the electric image method, which is an effective method to calculate the electrostatic field problem caused by the charge distribution of a conductor with a certain shape. He deeply studied the discharge oscillation characteristics of Leiden bottle, published a paper "Oscillating Discharge of Leiden Bottle" in 1853, and calculated the oscillation frequency, which made a pioneering contribution to the theoretical research of electromagnetic oscillation. He discussed the essence of electromagnetic field with mathematical method, and tried to unify electric power and magnetic force with mathematical formula. 1846 "moving image method of force, magnetism and current" was successfully completed, which is already the embryonic form of electromagnetic field theory (if we go further, we will have a deeper understanding of electromagnetic wave problems). He once wrote in his diary: "If I can re-examine the state of objects related to electromagnetism and current in a more special way, I will definitely go beyond what I know now, but that is of course something to come." His greatness lies in that he can introduce all his research results to Maxwell without reservation, and encourage Maxwell to establish electromagnetic phenomena's unified theory, which laid the foundation for Maxwell to finally complete the electromagnetic field theory.
He attaches great importance to integrating theory with practice. 1875 predicted that cities would use electric lighting, and 1879 proposed the possibility of long-distance power transmission. His ideas will come true in the future. 188 1 year, he reformed the motor and greatly improved its practical value. In electrical instruments, his main contribution is to establish accurate unit standards of electromagnetic quantities and design various precision measuring instruments. He invented mirror galvanometer (which greatly improved the measurement sensitivity), double-arm bridge, siphon recorder (which can automatically record telegraph signals) and so on, which greatly promoted the development of electric measuring instruments. According to his suggestion, the British Science Association established the Electrical Standards Committee in 186 1, which laid the foundation for the modern unit standards of electrical quantities. In engineering technology, from 65438 to 0855, he studied the signal propagation in cables and solved a series of theoretical and technical problems of long-distance submarine cable communication. After three failures and two years of research and experiment, Kelvin finally helped to install the first Atlantic submarine cable at 1858, which is a well-known work. He is good at combining teaching, scientific research and industrial application, and pays attention to cultivating students' practical working ability in teaching. At Glasgow University, he established the first extracurricular laboratory for students in Britain.
Tang Musun also applied physics to completely different fields. He studied the source of solar heat energy and the heat balance of the earth. His method is reliable and interesting, but just because he doesn't know that the energy of the sun and the earth comes from nuclear energy, it is impossible to get a correct conclusion. He tried to explain the source of solar heat energy by meteorite falling on the sun or gravitational contraction. 1854 or so, he estimated that the "age" of the sun is less than 5× 108, which is only one tenth of the value we know now.
From the temperature gradient near the earth's surface, Tang Musun tried to calculate the history and age of earth heat. His estimate is still too low, only 4× 108, while the actual value is about 5× 109. According to the evolution of geological phenomena, geologists soon found that his estimate was wrong. They can't refute Tang Musun's mathematics, but they are sure that his hypothesis is wrong. Similarly, biologists have found that the time course given by Tang Musun is contrary to the latest concept of evolution. This argument lasted for many years, and Tang Musun didn't understand that other people's opposition was correct. Finally, it was not until radioactivity and nuclear reaction were discovered that the premise of Tang Musun's hypothesis was completely denied.
Fluid mechanics, especially vortex theory, has become one of Tang Musun's favorite subjects. Inspired by Helmholtz's work, he found some valuable theorems. One of the gains of his voyage was that he invented a special compass suitable for iron ships in 1876, which was later adopted by the British navy until it was replaced by a modern gyro compass. Tang Musun's enterprise has produced many magnetic compasses and water depth detectors, from which huge profits have been made.
According to his practical experience and theoretical knowledge, Tang Musun felt an urgent need to unify electrical units. The introduction of metric system made the French Revolution a big step forward, but electrical measurement brought new problems. Gauss and Weber laid the theoretical foundation of absolute unit system. "Absolute" means that they have nothing to do with specific substances or standards, but only depend on universal physical laws. How to determine the proportion in the absolute unit system, how to choose the appropriate multiple factor to make it easy to be applied to industry, and how to persuade the scientific and technological community to accept this unit system are all important and difficult tasks. 186 1 year, the British Science Association appointed a committee to start this work, and Tom Musun was one of them. They worked hard for many years until 188 1, when an international congress led by Tang Musun and Helmholtz was held in Paris, and another congress was held in Chicago in 1893, they formally accepted this new unit system and adopted volts, amperes, farads and ohms as electrical units, and they were widely used since then. However, the problem of the unit system was not solved, and later some meetings changed the definitions of some standard quantities, and their actual values also changed, although the changes were small.
Kelvin was modest and diligent all his life, strong-willed, not afraid of failure and indomitable. Regarding the problem of dealing with difficulties, he said: "We all feel that difficulties must be faced squarely and cannot be avoided; We should keep it in mind and hope to solve it. In any case, every difficulty must have a solution, although we may not find it in life. " His spirit of unremitting struggle for the cause of science throughout his life will always be admired by future generations. 1896 at the meeting to celebrate his 50th anniversary as a professor at Glasgow University, he said, "There are two words that can best represent my struggle in scientific research in the past 50 years, and that is' failure'." This is enough to show his modesty. In order to commemorate his scientific achievements, the international metrology conference called the thermodynamic temperature scale (that is, the absolute temperature scale) Kelvin temperature scale, and the thermodynamic temperature is in Kelvin, which is one of the seven basic units in the current international system of units.
Kelvin's life is very successful. He can be regarded as one of the greatest scientists in the world. When he died on 1907 12 17, almost all scientists in Britain and all over the world mourned him. His body was buried next to Newton's tomb in Westminster Abbey.
Wei Gena
(2004-02-06)
Wei Gena (1880- 1930) is a German meteorologist and geophysicist. He was born in Berlin in June 1880+065438+ 10/,1 930+01.
Before the19th century, people did not begin to systematically study the geological structure of the whole earth, and did not form a fixed understanding of whether the oceans and continents have changed. 19 10, when Alfred Wegener, a German geophysicist, accidentally looked through the world map, he found a strange phenomenon: the west coasts of Europe and Africa on both sides of the Atlantic Ocean are far away from the east coasts of North and South America, and the outline is very similar, so the protruding part of one continent can just make up for the sunken part of the other continent; If we cut the two continents from the map and put them together, we can connect them into a roughly consistent whole. Comparing the contours of South America and Africa, we can clearly see this: the protruding part of Brazil, which goes deep into the South Atlantic, can just be embedded in the concave part of the Gulf of Guinea on the west coast of Africa.
According to his own investigation experience, Wei Gena thought it was no coincidence, and made a bold assumption: it was inferred that 300 million years ago, all continents and islands on the earth were connected to form a huge primitive continent called Pangu Land. Pan-continent is surrounded by a wider primitive ocean. Later, from about 200 million years ago, cracks appeared in many places in Pangea. Both sides of each crack move in opposite directions. When cracks expand and seawater invades, a new ocean is created. On the contrary, the primitive ocean is gradually shrinking. The divided land mass drifted to the present position, forming the familiar land distribution state today.
When Wei Gena was a teenager, he was eager to explore the North Pole. Because of his father's prevention, he failed to join the expedition after graduating from high school, but entered the university to study meteorology. 1905 After receiving his doctorate in meteorology with excellent results, he devoted himself to the research of high-altitude meteorology. 1906, he and his brother flew in the air for 52 hours in a high-altitude balloon, breaking the world record at that time. Later, he took part in an expedition to Greenland. The extremely deep impression left by the huge iceberg moving slowly on the island may have catalyzed his association and interest in the map of generate world. He began to use his spare time to collect geological data and look for evidence of sea-land drift.
1912 65438+16 October, Wei Gena delivered a speech entitled "the origin of the continent and the ocean" and put forward the hypothesis of continental drift. After that, I went to Greenland for the second time to study glaciology and paleoclimatology. In the subsequent World War I, his research work was interrupted and he was seriously injured on the battlefield. During his illness, he published the book Origin of Land and Sea in 19 15, which systematically expounded the theory of continental drift. In his immortal book The Formation of the Continent and the Ocean, he tried to restore the relationship between geophysics, geography, meteorology and geology that was cut off by the professional development of various disciplines, and demonstrated the continental drift with a comprehensive method. Wei Gena's research shows that science is an exquisite human activity, not a mechanical collection of objective information. When people are used to explaining facts with popular theories, only a few outstanding people have the courage to break the old framework and put forward new theories. However, due to the limitation of the scientific development level at that time, continental drift was criticized by orthodox scholars because of the lack of reasonable dynamic mechanism. Wei Gena's theory has become an idea that transcends the times.
As soon as the theory of continental drift was put forward, it caused an uproar in the field of geology. The younger generation cheered for this theory, thinking that it had created a new era of geology, while the older generation did not recognize this new theory. Wei Gena continued to collect evidence against his theory, so he visited Greenland twice and found that Greenland was still drifting relative to the European continent. He measured the drift speed of about 1 m per year. 1930165438+1October 2, when Wei Gena visited Greenland for the fourth time, he was hit by a snowstorm and fell on the vast snowfield, which was the second day of his 50th birthday. It was not until the following April that the search team found his body.
From 65438 to 0968, French geologist Lei Bixiong put forward the viewpoint of six plates on the basis of previous studies, namely Eurasia plate, Africa plate, America plate, India plate, Antarctic plate and Pacific plate. Plate theory solved the problem of drift dynamics that Wei Gena could not solve before his death, and made geology comprehensive to a new height. With the establishment of plate movement as the basic form of earth geological movement, earth science has entered a new stage of development. The continents will unite and separate for a long time, and the oceans will sometimes expand and close, which has become a recognized crustal structure map. In 1980s, people really thought that the theory of continental drift and the establishment of plate theory constituted a great revolution in the field of modern earth science.
Thirty years after Wei Gena's death, the theory of plate tectonics swept the world, and people finally realized the correctness of the theory of continental drift. It can be seen that a correct theory is often abandoned as a mistake in the initial stage, or rejected as a view opposite to religion, and accepted as a creed in the later stage. But in any case, what people still remember about Wei Gena today is not his cold reception and excitement after his death, but his scientific spirit of pursuing truth, facing the facts squarely, being brave in exploration and devoting all his life.