65438-0667 entered Trinity College for postgraduate study and obtained a master's degree the following year. 1669, Burton was recommended by Dr. Barrow, a professor of mathematics, as his successor. 1689 and 170 1, Newton was elected as a representative of Cambridge University twice.
1696 was hired as the supervisor of the mint. 65438-0703 President of Royal Society. 1727 died in London on March 20th (March 3rd of the new calendar).
Newton made a great contribution to science. In astronomy, his main achievements are in two aspects, namely, the study of astronomical optics and the discovery of the law of universal gravitation. 1666, Newton repeated the experiment of splitting sunlight into seven color bands with a prism. He correctly explained that this is caused by the different refractive indexes of different colors of light passing through glass. However, he believes that all kinds of glasses have the same refractive power, so refractive telescopes are not easy to manufacture.
In order to solve this problem, Newton polished a Cu-Sn alloy into a concave mirror for anti-spotlight imaging. 1672, Newton made a new reflective telescope, commonly known as Newton telescope. The telescope he made himself is still preserved as a precious exhibit in the Royal Society.
1666, Newton thought of gravity when he was avoiding the plague in his hometown. Newton once thought deeply when he saw the apple fall on the tree, and the concept of gravity entered his mind. His conclusion is that all objects are attracted to each other, and the resultant force of the attraction of all substances on the earth to apples is toward the center of the earth, so apples fall toward the center of the earth.
Furthermore, Newton extended the problem of objects attracting each other to the universe. He also believes that although the distance between the moon and the earth is 60 times that of radius of the earth, the gravity of the earth will definitely reach the moon. Then why doesn't the moon fall? This must have something to do with the movement of the moon around the earth. If the moon stops moving temporarily, it will undoubtedly fall to the earth, causing a catastrophic collision. It should be that the moon moves around the earth to avoid this disaster.
The concept of celestial bodies attracting each other was thought of by Newton before, such as the British physicist R. Hooke and others. They even guess that gravity is inversely proportional to the square of distance. Newton's contribution is that there is no doubt that the gravity of the earth and other celestial bodies does change according to this law. However, it will take a long time to complete this certificate. One reason is that there was a big error in the radius of the earth data at that time, which made Newton's initial calculation of the ratio of the centripetal acceleration of the moon's motion around the earth to the acceleration of gravity on the ground inconsistent with the law of inverse proportion to the square of the distance.
It was not until 167 1 year later that the French astronomer piccard calculated more accurate radius of the earth data, and it was possible to prove the force that made the apple fall to the ground, that is, the force that made the moon orbit the earth.
After understanding the problem that the moon moves around the earth, Newton can easily infer that the earth's movement around the sun is also controlled by the sun's gravity. Although the distance between other planets and the sun is different from that of the earth, their movements around the sun are bound to be dominated by their gravity.
Kepler had obtained three laws of planetary motion from the observation results before Newton, but why the planet should move according to these laws failed to give an answer. Newton solved the problem mathematically. Newton first proved that if the straight line between the planet and the sun sweeps the same area in the same time, the direction of gravity only needs to follow the straight line between the planet and the sun, regardless of the relationship between gravity and distance.
If the orbit of the planet is an ellipse and the sun is at a focus of the ellipse, Newton's mathematical reasoning can prove that the strength of gravity must be inversely proportional to the square of the distance from the sun to the planet. Assuming that the matter of planets orbiting the sun is also affected by the sun's gravity, mathematical methods are sufficient to prove Kepler's third law, that is, the square of the period of any two planets is directly proportional to the cube of the long axis of their orbits.
Through further research, Newton discovered many mysteries in celestial mechanics. He realized that not only the sun, the earth and the moon attract each other according to inverse square law, but also every particle in the universe attracts each other according to inverse square law.
Starting from this hypothesis, Newton proved that the external attraction of any uniform sphere can be replaced by particles of the same mass placed in its center. Newton also explained various phenomena of tides with the principle of universal gravitation, pointing out that the magnitude of tides is not only related to Wang Shuo, but also related to the gravity of the sun.
Newton also theoretically speculated that the two poles of the earth are relatively flat, and precession is caused by the perturbation of the sun on the equatorial bulge. Many of Newton's discoveries are contained in his immortal masterpiece Mathematical Principles of Natural Philosophy. This book was published in 1687. Since then, a brand-new branch of astronomy-celestial mechanics was born.