Cavendish Henry cavendish I. A brief biography of cavendish (henry cavendish,1731.10. ~1810.3.10.) is a British chemist and physicist. Born in Nice, France/KOOC-0/73/KOOC-0/year/KOOC-0/month/KOOC-0/year. 1742 ——1748 He studies at Heikner School near London. 1749- 1753 studied at Peter House College, Cambridge University. After living in London, cavendish worked as an assistant in his father's laboratory and did a lot of electrical and chemical research. His experimental research lasted for 50 years. 1760, cavendish was elected as a member of the Royal Society of London, and 1803 was elected as one of the foreign members of the French Society 18. 10 March 10, cavendish died in London and never married. Second, the contribution of science to Cavendish's talents is manifold. He studied the composition of the air near 1784 and found that nitrogen accounts for four fifths and oxygen accounts for one fifth in ordinary air. He determined the composition of water and proved that water is not an element but a compound. He also found nitric acid. Cavendish rarely published physics papers before his death. It was not until Maxwell reviewed and published his manuscript that people realized that he had made many important discoveries in electricity. He found that the acting force between a pair of charges is inversely proportional to the square of the distance between them, which is part of Coulomb's law later deduced by Coulomb. He proposed that there is "electricity" around every charged body, which is very close to the electric field theory; Cavendish proved that the capacitance of a capacitor is related to the substance inserted into the plate. The concept of electric potential was first put forward by Cavendish and played an important role in the development of electrostatic theory. He also suggested that the potential on a conductor is proportional to the current passing through it. Cavendish has research in thermal theory, thermometry, meteorology and geomagnetism. When he finished his last experiment, he was nearly 70 years old. In physics, his main achievement is to verify Newton's law of universal gravitation through the torsion balance experiment, and to determine the gravitational constant and the average density of the earth. Calculate the density of the earth: cavendish measured the density of the earth by finding the constants in Newton's law of universal gravitation and then calculating the density of the earth. His guiding ideology is extremely simple, using two big shot puts to get them close to two small balls. The mutual attraction between the balls is measured from the torsion angle of the line from which the balls are suspended. According to the law of universal gravitation, the constant g can be found. According to cavendish's many experiments, the average density of the earth is 5.48 1 times that of water (the current value is 5.5 17, and the error is about 0.65253%), and the gravitational constant (the gravitational constant G he measured is (6.754 0.04 1) × 65438) is determined. Known as the first person on earth. Cavendish's experiment to verify the law of gravity used his own "torsion balance" as a tool, which was later called the famous "Cavendish Experiment". Three. Anecdote 1. Cavendish, the richest scholar and the most learned millionaire, is said to have a lot of culture, but he didn't have the gentlemanly demeanor of England at that time. He is untidy, and almost no clothes can't be buttoned; He is unsociable, talkative, never married, and leads a strange reclusive life. In order to do scientific research, Cavendish turned the living room into a laboratory, and there were many observation instruments at the bedside of the bedroom, so as to observe the astronomical phenomena at any time. He inherited a large inheritance from his ancestors and became a millionaire. But he is not stingy at all. Once, one of his servants borrowed money from him because he was ill. Without hesitation, he wrote a check for10,000 and asked if it would be enough. Cavendish likes books very much. He numbered his large collection of books according to different categories and managed them in an orderly way. Whether he borrowed books or even read them himself, he went through the registration formalities without exception. Cavendish can be regarded as a scholar who lived and worked until he was 79 years old and was still doing experiments on the eve of his death. Cavendish won many nicknames in his life, such as Frankenstein, giant of science, the richest scholar and the most learned millionaire. 2. Regard fame and fortune as floating clouds in the sky. Once Cavendish attended a banquet, an Austrian scientist flattered Cavendish to his face. At first, he was embarrassed, but later he was at a loss. Finally, he stood up and rushed out of the room and went home in a carriage. Cavendish is taciturn. He often sits beside visiting guests without saying a word, thinking about scientific problems in his mind, which makes some idle literati feel embarrassed and disappointed. He devoted his life to scientific research and achieved fruitful results, but only published two unimportant papers. (In fact, it is because he is so withdrawn and shy that even he and the housekeeper need to communicate by letter; Even when I attend the weekly party held by the bank, I ask the participants to pretend that he doesn't exist and ask him for advice like no one else's watching. Maybe you can get a vague answer or an angry scream. The people in Cavendish Laboratory specially erected a monument for this great scientist in memory of him. Cavendish worked hard all his life, leaving a lot of legacy after his death, part of which was donated by his family to Cambridge University on 187 1 to establish Cavendish laboratory, which made great contributions to the progress of physical science and trained 26 Nobel Prize winners successively. 4. The manuscript that has been sleeping for a hundred years 18 10 After Cavendish died, his nephew Qizhi left 20 bundles of experimental notes left by Cavendish intact in the bookcase, and no one touched them. Who knows that this manuscript has been kept in the bookcase for 70 years. When it entered 187 1 year, when Maxwell, another electrical master, applied to be a professor at Cambridge University and was responsible for building the Cavendish laboratory, these notes full of wisdom and painstaking efforts got a chance to return to the world. Maxwell carefully read the work of predecessors 100 years ago and was shocked. He even lamented, "Cavendish is perhaps the greatest experimental physicist of all time. He almost foresaw all the great facts in electricity. These facts later became famous through the works of Coulomb and French philosophers. " Since then, McVeigh has decided to put aside some of his own research topics and try to sort out these manuscripts, so that Cavendish's brilliant thoughts can be circulated. It's really a masterpiece, the romance of two generations. Cavendish was born in England in 173 1. He spent his whole life in laboratories and libraries, and made many experimental explorations in chemistry, heat and electricity. However, due to his contempt for honor, he paid little attention to publishing experimental results and gaining priority in discovery, which led to many of his achievements not being published. It was not until the middle of19th century that people found some extremely precious materials from his manuscripts, which proved that he had made great contributions to the development of science. Cavendish's most acclaimed scientific contribution is that he first studied the distribution of charges on conductors and explained the law of electric power interaction with similar experiments in 177 1 year. In his report to the Royal Society in 1777, he said: "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 concentrated near the surface of the object. The electricity is tightly pressed together and the rest of the object is in a neutral state. " At the same time, he also studied the capacity of the capacitor; A group of capacitors with known capacity are manufactured and the capacitance of various instrument samples is measured. The dielectric constants of different substances are predicted, the dielectric constants of several substances are measured, and the concept of "potential" is put forward preliminarily. 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 is that he completed 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 cavendish hung a 6-foot-long wooden pole with a 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 shots with a diameter of 12 inches, measured the swing period caused by gravity between the two shots, and calculated the gravity of the two shots, and then calculated the mass and density of the earth by 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 in March 18 10. 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· Thomson, Rutherford, etc. Has presided over the laboratory.