In the early 1600s, Johannes Kepler proposed three laws of planetary motion. Kepler was able to summarize the carefully collected data from his mentor – Tycho Brahe – with three statements describing the motion of the planets in a sun-centered solar system. Kepler`s efforts to explain the underlying reasons for these requests are no longer accepted; Nevertheless, the laws themselves are still considered an accurate description of the motion of a planet and a satellite. Resonances in the solar system can also affect the spin and orbit of a body. Mercury`s rotation period, for example, is exactly two-thirds of its orbital period. Spin-orbit resonances are not paramount, but the result of spin-orbit development due to tidal friction. Tidal vibrations always cause mechanical energy to dissipate. Since angular momentum is conserved, the decrease in total system energy due to tidal interactions results in an exchange of angular momentum between the spin of a planet and the orbit of the tidal satellite. If the satellite`s orbital period is greater than the planet`s rotation period, the planet slows down as the satellite`s orbit expands. Observations suggest that the moon may have already orbited within 10 Earth radii of Earth, at which time the Earth day could have been less than 15 hours. When resonance states occur, resonance capture can occur, so the resonance pattern is maintained despite the continuous action of tidal forces.

The first seeds of Kepler`s laws were planted by father Heinrich Kepler and mother Katharina Guldenmann before his birth in 1571 in the Free Imperial City of Weil der Stadt, which is now part of the Stuttgart region of Baden-Württemberg. An important consequence of this development is that the evaluation of declarations is unlikely to be a purely formal process. By formal process, I mean those that rely solely on logical properties and not on substantial domain-specific information (R-squared is often considered a purely formal measure, as we`ll see below). Since the paradigmatic case of explanation is the citation of causes and that explanation includes context, we should expect that evaluating explanations will require a detailed argument based on domain-specific assumptions. Many types of causes can be claimed: distal, structural, necessary, sufficient, important, etc. In addition, when identifying causes, decisions must be made and justified about what to do within the causal field – causal factors that are treated as background and irrelevant. The combination of these variations will be part of the process of determining the contrast class and the relevance relationship, which will be determined by the interests of the explanatory seekers. We will see later that the formulation of such a complete set of elements in a statement can sometimes clarify controversies about the explanation in business. 6. What trend do you see in the last column of data? What Kepler`s law seems to support this? A closer and detailed look at scientific practice has led to the realization that context plays an essential role in many explanations and that it is sometimes useful to consider explanations as answers to certain types of questions [Garfinkel, 1981]. Questions and their answers have an inevitable contextual component.

When I ask, « Why did Adam eat the apple? » the question is ambiguous until I give the relevant contrast classes. Do I want to know why Adam and not Eve ate the apple? Do I want to know what Adam ate the apple instead of throwing it away? And so on. In addition, the basic knowledge of scientists looking for explanations determines what general information is relevant. For example, in physics before the advent of quantum mechanics, no response involving remote action would be considered relevant. If you stay clear about these contextual elements, you may find a more nuanced approach to the explanation, and we`ll see below that this can help clear up some standard confusions. Kepler formulated this third law in 1619[11] in an arduous attempt to determine what he considered the « music of the spheres » according to precise laws and to express it in musical notation. [19] It was therefore known as the harmonious law. [20] In astronomy, Kepler`s laws of planetary motion, published by Johannes Kepler between 1609 and 1619, describe the orbits of planets around the sun. The laws modified Nicolaus Copernicus` heliocentric theory, replacing its orbits and epicycles with elliptical trajectories, and explaining how planetary velocities vary.

The three laws state: Tycho Brahe`s meticulous and meticulous observations of the stars and planets provided Kepler with what we would now call a robust, well-controlled dataset to test his hypotheses about planetary motion (this way of describing it is, dear reader, a deliberate anachronism). In particular, Tycho`s observations of Mars` position in the night sky from Uraniborg were the main source of real-world data that Kepler used to derive and test its three laws. What Kepler`s third law actually does is compare the orbital period and radius of a planet`s orbit with those of other planets. Unlike Kepler`s first and second laws, which describe the motion properties of a single planet, the third law of astronomers compares the motion of different planets and calculates the harmonies of the planets. Tycho Brahe collected the data. Johannes Kepler analyzed the data. Isaac Newton explained the data – and this is the topic of the next part of lesson 4. Work on explanations in philosophy of science is an area where progress has been made, although many of it is negative. The nological deductive explanatory model dominated until the sixties. He equated explanations with derivatives of a description of phenomena to be explained from premises that essentially include scientific laws. There was (and still is) controversy about what a scientific law entails, but in general, laws were seen as non-random generalizations that did not refer to details and supported counterfactual claims.

Deriving Kepler`s laws from Newton`s laws of motion was a successful explanation; The claim that I found a penny in my pocket from the generalization « all the coins in my pocket are pennies » is not a successful explanation. The latter, unlike the former, involves an accidental generalization about an individual who does not support the counterfactual facts. Kepler`s first law states that the orbit is described by the equation: Newton was credited with understanding that the second law is not specific to the inverse quadratic law of gravity, as it is only a consequence of the radial nature of this law, while the other laws depend on the inverse quadratic form of attraction. Much later, Carl Runge and Wilhelm Lenz identified a principle of symmetry in the phase space of planetary motion (the orthogonal group O(4) acts), which in the case of Newtonian gravity explains the first and third laws, as well as the conservation of angular momentum via rotational symmetry for the second law. [17] Newton`s comparison of the moon`s acceleration with the acceleration of objects on Earth allowed him to determine that gravity keeps the moon in a circular orbit – a force that inversely depends on the distance between the centers of the two objects. Establishing gravity as the cause of the moon`s orbit does not necessarily mean that gravity is the cause of the planet`s orbits. How, then, did Newton provide credible evidence that gravity satisfies the centripetal force required for the elliptical motion of planets? It took nearly two centuries for the current formulation of Kepler`s work to take firm form. Voltaire`s Elements of Newton`s Philosophy of 1738 was the first publication to use the terminology of « laws ». [1] [2] The Encyclopedia of Astronomers` Biography notes in its article on Kepler (p. 620) that the terminology of scientific laws for these discoveries has been common since at least the time of Joseph de Lalande. [3] It is Robert Small`s account in An account of the astronomical discoveries of Kepler (1814) that formed the set of three laws by adding the third.

[4] Small also argued against history that these were empirical laws based on inductive reasoning. [2] [5] This implies that the sun could be the physical cause of the planetary acceleration. However, Newton states in his Principia that he considers forces from a mathematical point of view, not from a physical point of view, and thus adopts an instrumentalist view. [22] Moreover, he does not attribute a cause to severity. [23] where G is the universal gravitational constant. The constant of proportionality between force and acceleration in the equation.