He once saw an apple falling from a tree, and he wondered whether the force that pulled that apple to earth might also control the movements of planets. In the next 2o years, Newton perfected his theory. Using mathematics, he showed that a single force keeps the planets in their orbit around the sun. He called this force gravity (:
Newton's theories of gravity and the laws of motion, with the differential calculus he also invented (Leibnitz did the same in Germany), explained why the planets and other objects obey Kepler's laws of planetary motion, which were deduced from observations. It happens because of the Sun's gravity, an inverse-square force (which means that the force reduces with the square of the distance). Newton showed that a central force of this type produces an orbit exactly as Kepler had described many years before. Different planets at different distances, with a range of different initial conditions, take up a family of orbits that all follow the same theory.
One of the key discoveries discussed in Principia by Isaac Newton is the law of universal gravitation, which describes the attraction between two objects with mass. Newton formulated this law to explain the motion of celestial bodies such as planets around the Sun.
Johannes Kepler said that IF the planetary orbits are elliptical,THEN that would explain the measurements that Tycho Brahespent his whole life collecting.Isaac Newton said that IF gravity works the way he thought it does,THEN the planetary orbits have to be elliptical.But neither Kepler nor Newton could ever say that the orbits are REALLY ellipses.Both of their statements are 'only theories', just like the theory of evolution.They have never been proven.
Kepler's laws of planetary motion, which he formulated in the early 17th century, described the motion of planets around the sun but did not involve a formal understanding of gravity. Newton's law of universal gravitation, developed in the late 17th century, provided a theoretical explanation for Kepler's laws based on the force of gravity between masses. So Kepler did not believe in the same laws of gravity as Newton, but Newton's work built upon Kepler's observations.
Newton's derivation of Kepler's third law is an example of how theoretical physics can be used to explain and validate empirical observations. By applying his law of universal gravitation to Kepler's laws of planetary motion, Newton was able to mathematically derive Kepler's third law, providing a more fundamental understanding of the relationship between a planet's orbital period and its distance from the sun.
He once saw an apple falling from a tree, and he wondered whether the force that pulled that apple to earth might also control the movements of planets. In the next 2o years, Newton perfected his theory. Using mathematics, he showed that a single force keeps the planets in their orbit around the sun. He called this force gravity (:
He once saw an apple falling from a tree, and he wondered whether the force that pulled that apple to earth might also control the movements of planets. In the next 2o years, Newton perfected his theory. Using mathematics, he showed that a single force keeps the planets in their orbit around the sun. He called this force gravity (:
It was the result of hard work by Johannes Kepler, working at the start of the 17th century on new observations by Tycho Brahe. Kepler had a set of measurements of the planets' positions, and over a period of months and years he tried to explain the movements of the planets, because they did not exactly fit the old theories of Ptolemy and Copernicus. So he said to himself, let's try an ellipse, and it worked. At that stage he did not have a reason for the elliptical orbit, other than that it fitted the observations. Much later, Newton explained how a planet moving in the Sun's gravity must follow an elliptical orbit.
It was the result of hard work by Johannes Kepler, working at the start of the 17th century on new observations by Tycho Brahe. Kepler had a set of measurements of the planets' positions, and over a period of months and years he tried to explain the movements of the planets, because they did not exactly fit the old theories of Ptolemy and Copernicus. So he said to himself, let's try an ellipse, and it worked. At that stage he did not have a reason for the elliptical orbit, other than that it fitted the observations. Much later, Newton explained how a planet moving in the Sun's gravity must follow an elliptical orbit.
He once saw an apple falling from a tree, and he wondered whether the force that pulled that apple to earth might also control the movements of planets. In the next 2o years, Newton perfected his theory. Using mathematics, he showed that a single force keeps the planets in their orbit around the sun. He called this force gravity (:
If no force, the planets would move in a straight line, not in a orbit around the sun.
Kepler showed that three simple statements (Kepler's 'Laws') could explain all the planetary motions that Tycho had observed and recorded. Sir Isaac Newton ... after postulating the law of gravitation ... showed that the existence of gravity, in the form he wrote it, would naturally lead to Kepler's Laws.
As far as I know, Tycho Brahe made detailed observations of the planets' positions; he did NOT draw conclusions from that. Conclusions were drawn by other people, especially Kepler and Newton.As far as I know, Tycho Brahe made detailed observations of the planets' positions; he did NOT draw conclusions from that. Conclusions were drawn by other people, especially Kepler and Newton.As far as I know, Tycho Brahe made detailed observations of the planets' positions; he did NOT draw conclusions from that. Conclusions were drawn by other people, especially Kepler and Newton.As far as I know, Tycho Brahe made detailed observations of the planets' positions; he did NOT draw conclusions from that. Conclusions were drawn by other people, especially Kepler and Newton.
Newton's work explained how the planets follow Kepler's three laws of planetary motion, in detail, and therefore provided a huge boost to the general acceptance of the Kepler model. It could be described as the beginning of analytical science. Kepler found from observations that the planets follow elliptical orbits, and Newton showed that with an inverse-square gravity force between each planet and the Sun, the planet must conform with all of Kepler's laws. Along the way Newton produced important discoveries in theoretical science: the three laws of motion and the differential calculus, and all of those were necessary parts of his detailed work on the planets. From measurements of the planets' distances and sizes, along with observations of Jupiter's moons, it was then possible to use Newton's results to calculate the mass of all the planets and moons, and the gravity forces acting on them.
How is Newton's law of gravity related to the movement of the planets?
Kepler found from observations that the planets move in elliptical orbits. Newton then showed with his theoretical discoveries that the force of gravity from a massive central object produces elliptical orbits in smaller objects. The theories he used were the law of gravity, the laws of motion and the differential calculus. Using these he showed that an object in an elliptical orbit is continuously accelerating towards the central object. Its sideways velocity and mass prevent it from falling directly in.
Some say Newton discovered gravity because an apple fell on his head.