Physics of grade two in junior high school

Blaise pascal is a French mathematician, physicist and religious philosopher. Pascal's early research in natural science and applied science made important contributions to the manufacture of mechanical calculators and the study of fluids, expanded Torricelli's work and clarified the concepts of pressure and vacuum. Pascal also strongly defended the scientific method. Mathematically, Pascal has made contributions to two important new research fields. He wrote a paper entitled Projective Geometry at the age of 16, and began to discuss probability theory with pierre de fermat at 1654, which greatly influenced the development of modern economics and social sciences.

After a mysterious experience at the end of 1654, he left mathematics and physics to concentrate on meditation and philosophical and theological writing. He is a staunch believer of Ransen Sect, and his humanistic thought is deeply influenced by Montaigne. Lettres provinciales, a religious controversial work, is regarded as a model of French writing, and his notebook was later edited as Pensées.

Pascal's law discovered by Pascal is an important law in fluid mechanics. Pascal also became an international unit of pressure.

Archimedes

Archimedes (α ρ ρ ι μ? δη? 287-2 12), an ancient Greek philosopher, mathematician, physicist and scientist. Born in Syracuse, Sicily. Archimedes has been to Alexandria. It is said that he invented Archimedes screw pump when he lived in Alexandria, and it is still used in Egypt today. During the Second Punic War, Roman troops besieged Syracuse, and finally Archimedes died at the hands of Roman soldiers.

work

Methodology

Floating body

This book discusses the buoyancy of objects and studies the stability of rotating projectiles in fluids.

On balls and cylinders

Starting from several definitions and axioms, this book deduces more than 50 propositions about the area and volume of balls and cylinders.

The balance of a plane figure or its center of gravity

Based on several basic assumptions, this book demonstrates the principle of mechanics through strict geometric methods, and finds out the center of gravity of some plane figures.

Sand counter

This book is mainly about designing a method that can represent any large number.

Lever

On cracked cone surfaces and spheres

Quadrature of parabola

On the spiral

Otto von gehrig (otto von gehrig,1602165438+1October 20th-1may 686 1 1), a German physicist and politician, studied from1. He invented the piston vacuum pump in 1650, and used this invention to design and carry out the famous Madeleine's hemisphere experiment in 1657, which showed the atmospheric pressure and overturned Aristotle's hypothesis that "nature hates vacuum" (that is, there is no vacuum in nature).

Charles robert darwin (English: charles robert darwin, 1809 February 12- 1882 April 19), also known as Darwin, is a famous British biologist and naturalist. Darwin was famous for his geological research in his early days, and later he put forward scientific evidence to prove that all biological species are composed of a few *. In the1930s, Darwin's theory became the main explanation of evolutionary mechanism [1], became the basis of modern evolutionary thought, and could explain biodiversity scientifically and in a consistent and reasonable way, which was the cornerstone of modern biology [2].

While studying medicine at Edinburgh University, Darwin gradually became interested in natural history. He later went to Cambridge University to study theology [3]. Darwin became a geologist after sailing on the Beagle for five years. He observed and put forward theories to support Charles Lyell's viewpoint of uniform change. After returning to England, The Beagle Journey made him a famous writer. Darwin was puzzled by the geographical distribution of creatures and fossils he saw during his voyage. He began to study species transformation and put forward his theory of natural selection in 1838. Because this thought was regarded as heresy at that time, Darwin only revealed these thoughts to his close friends at first, and continued to conduct further research to deal with possible opposition [4]. 1858, alfred russel wallace sent him a paper with a similar theory, which prompted Darwin to decide to publish this theory with him [5].

The Origin of Species was published in 1859, which made the evolution from the same ancestor of * * * an important scientific explanation for the diversity of nature. Later, Darwin explained the role of human evolution and sexual selection in Emotional Expression of Humans and Animals and Origin and Sexual Selection of Humans. He also published a series of books on plant research. In the last book, Darwin discussed the influence of earthworms on soil [6]. In recognition of his outstanding achievements, Darwin was buried next to the tombs of Newton and John Herschel in Westminster Abbey, London, England.

[Editor] Early years

Darwin lived in 18 16, and his mother died a year later. Charles Darwin was born in Shrewsbury, Schopenhauer, England on February 1809. He ranks fifth among six children. His father robert darwin is a doctor and his mother Susannah Darwin is a financier. His grandfather Erasmus Darwin was a poet, a doctor and one of the early scholars who put forward similar concepts of evolution. Grandfather josiah Wedgwood is the founder of Wedgwood Ceramics Company.

Although the Wedgwood family once accepted the Anglican Church, most members of these two families belong to monotheism. Robert darwin, a low-key free thinker, baptized Charles in the Anglican Church. But later, Charles and his brothers and sisters followed their mother to attend monotheistic worship. 18 17, Charles entered a day school run by a priest. Charles' mother died in July of that year, when Charles was only 8 years old. Since September 2008, he has been a boarder in a nearby Anglican Shrewsbury School.

Darwin worked as a summer intern at 1825 to help his father treat the poor in Jopshire. That autumn, he entered the University of Edinburgh to study medicine. Darwin hated surgery and neglected his medical courses. However, he learned taxidermy from John Edmonstone, a freed slave who also taught him many legends about the rainforests of South America. Darwin quoted this experience in his later book "The Origin of Man" and explained that although Europeans and blacks are very different in appearance, they are actually very close [9].

In his sophomore year, he joined the burini Society, a student group devoted to natural history [10] and became a student under Robert Edmund Grant. Grant is a supporter of Lamarckianism, which advocates that evolution comes from acquired characteristics. This view put forward by Lamarck once appeared in Darwin's grandfather's works. Darwin then entered Grant's research team to study the life cycle of marine animals in the intertidal zone of Foss Bay. These studies have established evidence of homologous organs. Homology means that all animals have similar organs and indicate that they originated from the same ancestor [1 1].

1827 In March, Darwin published his findings in the burini Institute, which pointed out that the common black object in oyster shells was the eggs of ray leech [12]. He also took a course of Robert jameson, studying stratigraphic geology and plant classification. And assisted the large-scale collection work of Edinburgh University Museum, which was one of the largest museums in Europe at that time [13].

Later, because the father was dissatisfied with his son's academic progress, he sent Darwin to the Christian College of Cambridge University to study for a bachelor of arts course, expecting him to become a well-paid Anglican priest [14]. However, Darwin prefers riding and archery to reading [15], and he and his cousin William Darwin Fox like collecting racial beetles very much [16]. Later, Fox introduced Darwin to John Stevens Henslow. He is a professor of botany and a beetle expert. Soon after, Darwin joined Henslow's natural history course and became Henslow's favorite apprentice. The tutor called him "the man walking beside Henslow" [17][ 18].

When the exam approached, Darwin privately accepted Henslow's instruction, but at the same time focused on his studies. Darwin was particularly keen on William Paley's works, including Telelic Argument [19], which demonstrated the existence of God. 183 1 at the end of February, I got excellent results in theology and could cope with classics, mathematics and physics. Ranked in 178 customs clearance list 10[20].

Darwin stayed in Cambridge until June because of the need for accommodation. He accepted Hanslow's advice and did not immediately become a clergyman. Inspired by alexander von humboldt's personal narrative, he decided to go to Madeira Islands to study tropical natural history with some classmates after graduation. As a preparation, Darwin attended Adam sedgwick's geology course to help study Welsh strata. After spending two weeks in Barmouth with his friends, he went home to look for a letter from Hanslow. Henslow thought Darwin was a qualified naturalist and recommended him to follow robert fitzroy, the captain of the Beagle, without pay. At that time, Fitzroy was preparing to explore South America four weeks later and draw local nautical charts. Darwin's father initially opposed the two-year journey, thinking it was just a waste of time. However, he was later persuaded by his wife's younger brother, josiah Wedgwood II, to allow his son to take part in the voyage.

[Editor] The Beagle Tour

The Beagle explored for five years, during which Darwin spent two-thirds of his time on land. He carefully recorded a large number of geographical phenomena, fossils and organisms, and systematically collected many specimens, many of which were new species in science. Every once in a while, he sent the specimens collected during these voyages and the letters recording these discoveries to Cambridge University, and soon he became a famous naturalist. Darwin's detailed exploration records showed the amazing talent of a theoretical pioneer and became the theoretical basis of his later works. The first edition of his travel notes for his family was later published as A Journey to Beagle, which described and summarized the customs of aborigines and colonies in detail from the perspectives of sociology, politics and anthropology. [22]

Darwin fell ill during the voyage. [23] 1833 10, he suffered from severe fever in Argentina. 1834 In July, on his way back to Valparaiso from the Andes, he fell down again and lay in bed for a month. [24]

Before they leave, Robert? Fitzroy gave Darwin a roll of Charles? Charles Lyell's Principles of Geology (he got the second volume in South America). This book interprets topography as the result of gradual evolution over a long historical period. When Darwin arrived in Cape Verde, Santiago, the first stop of his journey, he noticed that there was a layer of white sediment high on the volcanic cliff there, which contained many exposed coral and shell fragments. This explains Ryle's theory well, gives Darwin a new perspective to think about the geological history of islands, and makes him decide to write a book on geology. [25] In the following journey, Darwin made more discoveries, many of which were remarkable. [1] In Patagonia, he saw boulders and seashells distributed in the secondary direction, which were actually raised beaches. After the earthquake in Chile, he found that the mussel bed was stranded on the tide, which showed that the land had risen. High in the Andes, he found a fossil tree standing on the beach, surrounded by shells. After Biegel explored the Corcos Islands, he came to the conclusion that these coral islands were formed on sunken volcanoes. [26]

In South America, Darwin discovered and excavated some extinct giant mammal fossils, and quite a few of them were not in the geological layers with signs of bad weather changes and disasters. In his view, an animal's skull belongs to an African rhinoceros. In addition, he judged that some animal nail fragments came from a prehistoric giant armadillo two to three times the size of the common armadillo in this area, but he was misled by the Dictionnaire classique of Bory de Saint-Vincent, and he turned to believe that it was part of the remains of the genus ground sloth found around him. . [27] In the second volume of Ryle's book, the creation of all things belongs to the "creation center", and Darwin, who has been ahead of the times, is puzzled by this. [28]

During Berger's last visit to Tierra del Fuego, three Indians (Native Americans) were sent back to their hometown and became missionaries. During their two years in Britain, they were educated by the British tradition and entered the familiar "civilized society". However, their relatives were "incorrigible insulting scum" to Darwin. [29] A year later, the missionary's mission was forgotten by them, and only Jamie Barton told them that he would rather live a hard life than return to England. Because of this, Darwin re-examined human beings. He came to the conclusion that although human beings are higher animals, the nature of animals has never been lost as his friends said. He understands that the evolution of every civilization is different and is not determined by race. When he saw the atrocities committed by European colonists against the aborigines in South America, New Zealand and Australia, he strongly opposed slavery and felt sad for these barbaric acts. [30]

Captain fitzroy has been writing the official diary of the Beagle trip. At the end of the trip, he read Darwin's diary, and then asked him to revise it again for the third volume of natural history. [3 1]

1809 was born in a doctor's family in Shrewsbury, England.

From 1825 to 1828, he studied medicine at Edinburgh University, and then studied theology at Cambridge University.

183 1 After graduating from Cambridge University in, he traveled around the world for five years (183 1- 1836) as a naturalist.

French physicist André-Marie Ampère (1775- 1836) has made outstanding achievements in the research of electromagnetic action. Ampere, the international unit of current, is named after its surname.

[Editor] Life

1778 was born in Lyon, France. It is said that Ampere was found to be brilliant in his early years. Ampere's father taught him Latin at first, but soon found that Ampere's mathematical talent was particularly outstanding, so he turned to teach him mathematics. However, in order to learn the works of Euler and Bernoulli, Ampere insisted on completing the study of Latin. As I recall, all his mathematical knowledge was basically completed at the age of 18. Ampere has a wide range of interests, including history, travel, poetry, philosophy and natural science.

Ampere met his wife on 1796 and got married on 1799. 1806, he was hired as a professor of physics and chemistry at Borg College, so he had to be separated from his young son and his sick wife. 1804, his wife died, which was a great blow to Ampere. In the same year, he began to teach at the Paris Institute of Technology, and 1807 became a professor of mathematics. During this period, he published some papers on probability theory and mathematical analysis.

1820, Oster discovered the current magnetic effect, and Ampere immediately devoted himself to the study. Within a few weeks, he proposed Ampere's law, the right-hand spiral law. Soon after, three papers were published in a few months, and nine famous experiments were designed, summarizing the motion law of current elements in electromagnetic field in current-carrying circuits, that is, ampere's law. 182 1 year, Ampere put forward the molecular current hypothesis and the electrodynamics theory for the first time.

1836, Ampere died in France.

[edit] evaluation

Ampere's research on electromagnetic action ended the previous understanding of the separation of electricity and magnetism, and his molecular current hypothesis revealed the electrical nature of magnetic phenomena, which laid the foundation for the later development of electromagnetism. Maxwell, the founder of classical electrodynamics, spoke highly of Ampere's work, calling his research "one of the most brilliant achievements in the history of science". Later generations also called ampere "Newton in electricity".

Countalessandro Giuseppe Antonio Anastasi o Volta (1745 February18-1827 March 5), an Italian physicist, is famous for developing batteries in 1800. Later he was made an earl.

all one's life

Volt was born in Cuomo and attended the local public school. 1775, he became a professor of physics at the Royal College of Como. The next year, he perfected an invention that produced electrostatic charge-electrophoresis.

From 1776 to 1777, he devoted himself to chemistry, studied atmospheric electricity, and conducted different experiments such as igniting gas with electric spark in a closed container. From 65438 to 0779, he became a professor of physics in university of pavia, where he served as a professor for 25 years. Before 1800 years ago, he successfully developed an early battery, called a voltaic reactor, which was made of stable current.

18 10, Napoleon recognized his contribution to electric power science and made him an earl. Cuomo built a museum called the Temple of Volta for him to display the original of his experimental instruments. The Vilti Ann Foundation near Lake Como is also committed to promoting scientific activities. Walter devoted himself to scientific research and introduced the first wholesale medicine in Como.

Georg simon ohm is a German physicist. Ohm discovered the proportional relationship between current and voltage in resistance, that is, the famous ohm's law; He also proved that the resistance of a conductor is directly proportional to its length and inversely proportional to its cross-sectional area and conductivity. In the case of stable current, the charge moves not only on the surface of the conductor, but also on the whole cross section of the conductor. The international system of units "ohm" of resistance is named after him.

Early life

Ohm 1789 was born in a locksmith's family in Hellem, Germany on March 6th, 2006. His father Joan Wolfgan Ohm was a locksmith, and his mother Maria Elizabeth Baker was the daughter of a tailor in Hellem. Ohm's parents have not received formal education, but his father is a respected person, and his self-study level is high enough for him to give his children an excellent education. Some of Ohm's brothers and sisters died in childhood, and only three children survived, namely him, his younger brother Martin Ohm (1792- 1872), who later became a famous mathematician, and his sister Elizabeth Barbara. His mother died when he was ten years old.

In early childhood, Georg Simon and Martin were taught a high degree of mathematics, physics, chemistry and philosophy by their father. Georg Simon went to Herun Root High School at the age of 1 1 to 15, where he received a little scientific knowledge and felt that what he taught at school was quite different from what his father taught. At the age of 15, georg simon ohm was tested by Karl Christian von Langsdorf, a professor at the University of Herun. He noticed Ohm's outstanding talent in the field of mathematics, and even wrote in his conclusion that another pair of Bernoulli brothers would be born from the locksmith's house.

[Editor] University life

1805, 16-year-old Ohm entered Herun University to study mathematics, physics and philosophy. Instead of focusing on his studies, he spent a lot of time dancing, skating and playing billiards. Ohm's father was very angry with Ohm for wasting educational opportunities, so he sent Ohm to Switzerland. 1September, 806, Ohm worked as a math teacher in a school in Gottstadt bei Nydau.

[Editor] Teaching career

Karl Kristen van Langestoffer left Herun Genuniversity to teach at Heidelberg University on 1809. Ohm proposed to go to Heidelberg with him to start his math study again, but Langestofer suggested that Ohm continue to teach himself math and read the works of Euler, Laplace and Laclau. Ohm accepted Langes's advice and continued to teach himself mathematics. At the age of 22, Ohm returned to Hellem, where he received his Ph.D. in the thesis 18 1 Licht und Farben (light and color), and then worked as a math lecturer in Hellem for three semesters. Then he taught in Bamberg in 18 13, cologne in18/7 and Berlin in 1826.

Ohm's main research interest was electricity, which had not been widely studied at that time. 1833 became a professor at the Royal Institute of Technology in Nuremberg, 1839 became the president of the school, 1849 became a professor at the University of Munich, and 1852 became a professor of experimental physics.

Ohm died and was buried in Munich.