Collection

zero Useful+1

zero

Giovanni Domenico Cassini

French astronomer and hydraulic engineer

Giovanni Domenico Cassini was born in Perrinaldo, Italy, on June 8, 1625, and died in Paris, France, on September 14, 1712. He was a French astronomer and hydraulic engineer born in Italy. He discovered the gap between Saturn's rings, hence the name Cassini Slit.

one's native heath: Perrinaldo, Italy
date of birth: June 8, 1625

Date of death: September 14, 1712
Key achievements: Found a gap in the middle of Saturn's ring
True name: Giovanni Domenico Cassini

catalog

six anniversary
seven contribution

brief introduction

Announce

edit

Giovanni Domenico Cassini (Italian: Giovanni Domenico Cassini, June 8, 1625-September 14, 1712), Jean Dominique Cassini (French: Jean Dominique Cassini) Italy Born France Nationality Astronomers and hydraulic engineers 。 Units that have worked in the past include: Panzano Observatory 、 university of bologna Professor of astronomy, and in 1671 Observatoire de Paris After completion, he became the first director of the station until his death.

detailed information

Announce

edit

Cassini was born in 1625 Italy Of Perinaldo , on 1648 to 1669 During the Panzano Observatory Work. 1640 From university of bologna astronomy professor , and on 1671 Observatoire de Paris After completion, he became the first director of the station until his death. 1673 Joining France nationality , renamed French , namely Jean Dominique Cassini, also known as Cassini I (his great grandson has the same name as him, known as Cassini II).

Cassini is a conservative astronomer, he does not accept Copernicus The heliocentric theory of Kepler's law 、 Isaac Newton Of Law of universal gravitation and light speed Limited theory. Cassini became blind in 1711 and died in France the following year (1712) Paris 。 In addition to his contributions to astronomy, he has also been pope Delegated governance Po River Prevention and control, management and flood control works of.

Contemporary human exploration Saturn Of detector “ Cassini ”Namely, it is named after him.

Astronomical discovery

Announce

edit

Cassini

Giovanni Domenico Cassini was born in 1625. He grew up and received education in Italy. Cassini was obsessed with astrology instead of astronomy His profound astrological knowledge won him a wide reputation. Although he wrote an article proving that astrology is not reliable in predicting the future, many people still tried to find him for advice. In 1668, Cassini carried out a series of astronomical studies in Italy, which was widely praised. Later, the Paris Observatory offered him the post of director. Shortly after arriving in Paris, Cassini decided to become French and changed his name to Jean Dominique Cassini.

Cassini carefully brought an improved high-performance telescope from Italy to continue a series of astronomical explorations, and soon he became One of the most famous scientists in the world at that time 。 His discoveries include the rotation periods of Mars and Saturn, as well as a dark slit in Saturn's ring - still known as the Cassini slit.

Think the speed of light is limited

Cassini was the first to believe that light speed He was one of the limited people, but he refused to release the evidence. Later, he even spent several years trying to prove that this theory was wrong. He is a devout religious believer and believes that light is created by God, so it must be unlimited and not limited by the speed of transmission. However, all his astronomical discoveries prove that light travels at a fixed and limited speed. As faithful Catholicism Believer, Cassini believes that the earth is the center of the universe. But in 1672, Kepler's early writings and Copernicus' rigorous argument made him at least begin to believe that the sun may be the center of the universe.

Measurement process

This idea prompted Cassini to decide to measure the distance between the earth and the sun. However, direct measurement is difficult and dangerous (sunlight may lead to the loss of vision of the measurer). fortunately Kepler equation He helped Cassini. As long as he could measure the distance between the earth and any planet, he could use the equation to calculate the distance between the earth and the sun. Mars is close to the earth, and Cassini is familiar with Mars, so he decided to use an improved telescope to measure the distance between the earth and Mars. Of course, it is impossible for him to actually measure, but if he can measure the angle from two different points on the earth to a certain same point on Mars at the same time, he can use these two angles and triangular geometry to calculate the distance to Mars.

If the calculation is accurate, the linear distance between two points on the earth must be far, and this distance must be an exact known number. Cassini sent French astronomers Jean Richer (Jean Richer) French Guyana Cayan in the region, he stayed Paris 。

On the same night in August 1672, the two men measured the angle with Mars at the same time and made the angle face the distant sky. After Richel brought the measurement data back to Paris, Cassini could calculate the distance from Mars. He used Kepler's equation to find that the distance between the earth and the sun is 8.7 × 107 miles. Modern science has proved that the error between Cassini's calculation results and the actual data is 7% (the actual distance is about 9.3 × 107 miles).

Cassini successively calculated the distance between the earth and other planets, and he found that Saturn leave earth It's 1.6 × 109 miles away! Cassini's discovery means that the universe is millions of times larger than people originally thought.

measure

Announce

edit

measure longitude It is important for both mapping and navigation. One of the most important inventions of the 17th and 18th centuries was the invention of an accurate method for measuring longitude. The first major achievement in cartography was Giovanni Domenico Cassini, who began to use it in 1681 Galileo Galilei The proposed method of observing Jupiter's satellites to determine longitude. This observation is even more difficult without professional astronomers at sea. The clock invented by John Harrison, which still runs accurately on ships, finally enables people to measure longitude accurately on ships.

Cassini's law In 1693, Cassini proposed that it was a description Moon The law of operation.

The first is that the time for the moon to rotate on its axis is equal to the time for the moon to circle the earth. Therefore, the moon always faces the earth on the same side.

Second, the equatorial surface of the moon and The earth revolves around the sun The orbital plane (ecliptic plane) has a fixed included angle of about 1 ° 32 '. The third one is the intersection point of the lunar orbital plane, the lunar equatorial plane and the ecliptic plane, which is the ascending intersection point of the lunar equator and the descending intersection point of the lunar orbit.

achievements

Announce

edit

Cassini is believed to have been discovered at the same time as Hooker Great erythema (1665) 。 Cassini was the first to find Saturn Four satellites of（ Iapetus, Rhea, Rhea, and Rhea ）And he is still 1675 Found Cassini Division 。 1690 He's observing Jupiter atmosphere Found at Jupiter The equator rotates faster than the poles, so we found Jupiter Of Poor autorotation 。 He also found that Jupiter Great erythema 。 In 1675, he found that Saturn's rings There is a hidden seam in the middle, which was later named after him Cassini circular seam 。 He guessed that the halo was composed of numerous small particles; More than two centuries later, his conjecture proved correct. From 1671 to 1679, he carefully observed Moon The surface characteristics of, presented in 1679 French Royal Academy of Sciences A large amount Lunar chart In more than a century, no one has ever surpassed him in this respect. From March 1683, Cassini studied Ecliptic light , think it is due to Interplanetary dust Reflected sunlight is not an atmospheric phenomenon.

Cassini, a conservative astronomer, refused to accept Copernicus We also oppose Kepler's law, Isaac Newton's law of gravitation and the theory of limited speed of light. Cassini died in Paris, France, in 1712. In addition to his contributions to astronomy, he was also appointed by the Pope to administer the control, management and flood prevention works of the Po River. Modern human probes for Saturn“ Cassini ”Named after him

anniversary

Announce

edit

Cassini circular seam

Cassini Huygens is NASA , European Space Agency and Italian Space Agency The main task of the project is to carry out space exploration of the Saturn system. Cassini Huygens Saturn probe It is the largest and most complex planetary probe ever launched by mankind. Cassini detector It is named after Giovanni Domenico Cassini, an Italian born French astronomer and the discoverer of Saturn's annular slit. Its mission is to circle Saturn Flight. From October 15, 1997 Kennedy Space Center The Cassini Huygens spacecraft, which was launched, arrived around Saturn in July 2004. The project consists of two parts: the Cassini orbiter will orbit Saturn and its satellites for four years, and Huygens The detector will go deep titan The atmosphere surrounded by dense fog and landed on its surface. The precision instruments installed on these two detectors will provide scientists with important data to help clarify this mysterious and vast area.

Cassini Huygens is a collaborative effort of three space agencies from different countries. Seventeen countries participated in the construction of the spaceship. The Cassini orbiter is owned by NASA Jet Propulsion Laboratory Construction and management. The Huygens probe was built by European Space Agency Construction. The Italian Space Agency provided Cassini with High gain antenna 。 A total of more than 200 scientists from all over the world will participate in the research of the collected data.^[1]

contribution

Announce

edit

Astronomy

Cassini worked at Panzano Observatory from 1648 to 1669. Since 1640 University of Bologna (University of Bologna) Professor of astronomy, and became the director of the Paris Observatory in 1671.

Cassini is believed to have discovered erythema magna at the same time as Hooke (~1665). Cassini was the first to discover four moons of Saturn; He also found out Cassini Division (1675). Cassini was also the first to discover Jupiter's poor rotation. When he observed Jupiter's atmosphere in 1690, he found that Jupiter's equator rotated faster than its poles. He also found the great red spot on Jupiter.

In 1675, a dark slit was found in the middle of Saturn's halo, which was the famous Cassini slit later named after him. He guessed that the halo was composed of countless small particles. The spectroscopic observation more than two centuries later confirmed his conjecture.

From 1671 to 1679, he carefully observed the surface characteristics of the moon. In 1679, he sent a large lunar surface map to the French Academy of Sciences, and no one could surpass him in this respect for more than a century.

water conservancy project

In addition to his contributions to astronomy, Cassini was also appointed by the Pope to administer the control, management and flood control works of the Po River.

Novice on the road

Growth task Getting Started with Editing Edit Rule Edit by myself

I have questions

Content query Online Service Official post bar Feedback

Complaints and suggestions

Report bad information Failed to appeal through entries Complaint of infringement information Blocking query and unblocking

Jinggong Network Anbei No. 1100000200001