Evangelista Torricelli (1608-1647) Italyphysical scientistMathematician.He was born in Farnza on October 15, 1608 and died in Florence on October 25, 1647.Torricelli isGalileoHe succeeded Galileo as professor of mathematics at Florence College in 1642.[1]
Evangelista Torricelli,ItalyphysicsConcurrentmathematician, to inventbarometerAnd famous.On his 39th birthday, he suddenly fell ill and died.But in his short life, he has made many outstanding achievements and won a high reputation.
GalileoTorricelli, the defender of the doctrine, was born inItalyA wealthy aristocratic family in Huayecha.He has received a good mathematics education since he was young.By the age of seventeen or eighteen, his outstanding mathematical ability had begun to shine.So when he was 20 years old, his uncle took him toRome, taught by Galileo's student Castelli.Castelli was a well-known mathematician and hydraulic engineer at that time. He had outstanding achievements in many aspects of mathematicshydraulicsThe foundation of science has been established.Castelli saw that Torricelli was young and intelligent and loved him very much, so he appointed him as his private secretary to give him academic guidance.
After Galileo died in 1642, Torricelli succeeded Galileo as a member of the Florence Academy of SciencesphysicsandmathematicsProfessor, and was appointed chief mathematician of the court.Since then, he has the money to do some experimental research and is no longer only engaged in theoretical exploration as before.Later, Torricelli greatly enriched the contents of "the fifth and sixth days" in Galileo's Dialogue between Two New Sciences.
Torricelli lived in Florence for five years until his death.In the past five years, he has carried out a lot ofscientific research, and met paintersRosa, ancient Greek scholar Dadi and hydraulic engineerAliGai Ti was widely respected by the upper class.He was also invited to give 12 academic speeches at the Fur and Fur Society, with a wide range of topics, including 6 on physics.These speeches are flawless in terms of language and words, which are unparalleled by ordinary people. They are typical Italian literary works.His speech was also full of the fighting spirit of the Renaissance era, attacking those who tried their best to defend the obstinate and conservative forcesCatholicismThought cheers Galileo's achievements and defends Galileo's theory many times.
Character's Life
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Stone statue in Florence Museum of Science and History, Italy
Torricelli was born in ItalyFaenza, part of the Papal State.Like an orphan, he was abandoned by his father and left to his uncle to take care of him. His uncle, a monk named Camaldis, sent young Torricelli tothe society of jesusCollege to studymathematicsandPhilosophy, has been studying in 1626.In 1627, TorricelliRomeLearn sciencePisaOfUniversity of Romeprofessor of mathematicsBenedict ·Benedetto Castelli。
Torricelli studied deeplyGalileoOf《Dialogue between two new sciences》This book.And learned aboutDynamicsMany inspirations from the development of the principle.In 1641, Torricelli published his book "On the Movement of Weights", which attempted to explain Galileo'sdynamicsThe law draws new conclusions of its own.When Castelli visited Galileo once, he showed Galileo the works of Torricelli and warmly recommended Torricelli.After reading Torricelli's comments, Galileo expressed his great appreciation for his excellent ideas, and invited him to come as an assistant.Torricelli cameFlorence, met with Galileo, who was blind and lay in bed all day.In the last three months of his life, Torricelli and his students served as reporters of Galileo's dictation and became Galileo's last students.
Apart from some letters, there is very little information about Torricelli's activities in 1632 and 1641, that is, Castelli told Torricelli aboutProjectile motionThe period when the path paper was sent to Galileo (after that, Galileo was placed under house arrest in hisAchetriIn the villa).Although Galileo immediately invited Torricelli to visit, he was not invited to visit until three months before Galileo died.During his visit, he also recorded Galileo's Fifth Day Essay.After Galileo died on January 8, 1642,Grand DukeFerdinand II de MediciAsked him to take over Galileo's mathematicsdukeandUniversity of PisaAs a professor of mathematics.During his tenure, he solved many important mathematical problems at that time, such as findingcycloidArea and center of gravity.He also designed and produced manytelescopeAnd simpleMicroscope。
A few days after Florence caught typhoid fever, Torricelli died and was buried inSan Lorenzo。In memory of him,asteroid7437 was named Torricelli.He left all his inheritance to his adopted son Alexander.
At that time, the academic community was still unclear about whether there was weight in air and whether vacuum might exist, mainly due toAristotleThe legacy of thought believes that "fire andatmosphereEach has its own weight. "And adhere to the saying that nature is "afraid of vacuum".Galileo doubted this statement. He said: "We can't believe what Aristotle said. We just think that something is light and something is heavy. We should realize that all objects have their own weight, but each has its own weight and density.""If people cannot recognize the existence of vacuum by feeling and understanding, then how can they deny the existence of vacuum by feeling and understanding?" Galileo once found that the pump could not pump water to a height of more than 10 meters when it was working. He attributed this phenomenon to the fact that the water column could not bear its own weight, and could not find a reasonable and satisfactory explanation.
Torricelli firmly agreed with Galileo's statement that air has weight and vacuum exists.On the basis of summarizing previous theories and experiments, Torricelli carried out a large number of experiments, realized vacuum, verified the fact that air has weight, and denied Galileo's statement about vacuum force.
Around 1641, a famousmathematician、astronomerBerti once made a vacuum experiment with a 10 meter long lead pipe.Torricelli was inspired by this experiment and thought of usingdensityOf seawaterHoney、MercuryAnd so on.The mercury experiment he selected achieved the most successful results.He filled a 1m long glass tube with mercury, and then pressed his finger against the tube mouth, and inverted it into the mercury tank containing mercury. After releasing his finger, it can be seen that the mercury on the top of the tube inside has fallen, leaving room, while the lower part is still full of mercury.In order to further prove that the upper part of the mercury surface in the tube is indeed vacuum, Torricelli improved the experiment.He filled the tank with clean water from above the mercury surface in the mercury tank, and then slowly lifted the glass tube upward. When the glass tube mouth was raised above the interface between mercury and water, the mercury in the tube quickly leaked out, and the water suddenly went up into the tube to the top of the tube.It can be seen that the part above the mercury column in the original tube is really empty.The previous mercury column and the current water column are not attracted by any vacuum force, but are held by the pressure generated by the air weight on the mercury surface outside the tube.Torricelli's experiment was the last fatal blow to Aristotle's mechanics, so some people tried to deny Torricelli's research results and proposed that the upper end of the glass tube was filled with "pure air", not vacuum.Everyone expressed his own views, and there were many different opinions, which caused a heated debate.The argument continued untilPascalThe theory of Torricelli was gradually unified after the success of the experiment.
Torricelli also found in the experiment that the vertical height of the mercury column in the tube is always 76 cm regardless of the length of the glass tube and the inclination of the glass tube, so he proposed that the height of the mercury column can be used to measureAtmospheric pressureAnd cooperated with Viviani in 1644 to make the world's firstMercury barometer。This discovery perpetuates his fame, and the unit of vacuum measurementBracketIt was named after him.
Torricelli's law
Torricelli also found Torricelli's law, which is a law about the flow rate of fluid flowing out of the opening, that is, the velocity of liquid ejected from the small hole at the bottom of the tank is equal to the square root of twice the product of gravity acceleration and liquid height.It was later proved thatBernoulli's lawA special case of.
At that time, the hydraulic authority Castelli believed that the velocity of the water flow was proportional to the distance from the hole to the water surface, and this insight was approved by Galileo, and no one dared doubt it.In order to find out this truth, Torricelli made experiments and measured carefully.It is found that the velocity of the water flowing out of the small hole on the wall is not proportional to the distance from the hole to the water surface, but proportional to the square root of the distance.The relationship between the initial flow velocity v and the height difference h between the water surface in the bucket and the orifice is v=A √ h (A is a constant).Later people called this formula Todd's jet law.About a century after him,Daniel Bernoulli Then we get the result that v=√ 2gh.Torricelli later proved through experiments that the trajectory of the water jet from the side wall pores isparabolaShape.Torricelli's discoveries laid the foundation for making fluid mechanics an independent branch of mechanics.
Describe the formation of wind
Torricelli was the first person to describe wind in a scientific way. He wrote: "Wind originates from the difference in temperature and air density between two regions of the earth."
Contribution in mathematics
Torricelli also has high mathematical attainments.His greatest contribution to mathematics is to further developKavalieriThe "inseparable principle" ofNewtonandLeibnizCreatedCalculus。He put forward many new theorems in the Collection of Geometry, such as:Cartesian coordinatesThe method of converting to cylindrical coordinates, the theorem of calculating the center of gravity of plate objects with regular geometry.And successfully combinedDynamicsQuestion to studygeometry。For example, he studied the problem of making a tangent line on the parabola described by the object thrown out at a certain speed in the horizontal, and also studied the envelope of the parabola described by the object.He has measured the area in the parabolic arch, the volume in the paraboloid and solved other very complicated problemsgeometryDifficulties.
Torricelli also wrote Cavalieri's principle of indivisibility in an easy to understand way, which was very popular among readers and promoted the popularization of the principle of indivisibility.[2]
