A perverted space-time geodesy results from the notions of variable rods and clocks, which are taken to have their length and rates affected by the gravitational field. On the other hand, what we might call a concrete geodesy relies on the notions of invariable unit-measuring rods and clocks. In fact, this is a basic assumption of general relativity. Variable rods and clocks lead to a perverted geodesy in the sense that a curved space-time might be seen as (...) arising from the departure from the Minkowskian space-time as an effect of the gravitational field on the rate of clocks and the length of rods. In the case of a concrete geodesy we have “directly” a curved space-time whose curvature can be determined using (invariable) unit-measuring rods and clocks. In this paper, we will make the case for the plausibility that Einstein's views on geometry in relation to general relativity are permeated by a perverted geodesy. (shrink)

This thesis tells the story of a surprisingly difficult problem in gravitational physics: deriving and measuring the shape of our planet. Chapter 1 reconstructs the emergence of gravitational theories of planetary equilibrium figures and quantitative measurements of the Earth’s shape and surface gravity (c. 1660-1730). I show that early geodesists made substantial empirical progress despite deep theoretical disagreements about the nature of gravitation. Chapter 2 reconstructs how geodesy came to offer a decisive test of the interactive nature and compositionality (...) of gravitation (c. 1740-1825). I retell how Pierre-Simon Laplace established that the Earth’s external attraction is the resultant force of the mutual attractions between its constituent particles; a momentous but overlooked achievement in the history of gravitational physics. Chapter 3 traces the numerical conflicts in the measurement of the central quantity characterising Earth’s figure: its ellipticity. These conflicts persisted throughout the nineteenth century and complicated the coordination between geodetic models and measurements. Chapter 4 reconstructs how geodesists finally achieved convergent measurements of Earth’s ellipticity between 1880 and 1924. Jointly, the four chapters illustrate key steps in obtaining strong evidence for quantitative claims about a complex and partially inaccessible system: using measurements to initiate theoretical inquiry (chapter 1), using measurements to conduct severe tests of theoretical laws (chapter 2), using discordant measurements to study second-order phenomena (chapter 3), and using multiple alternative measures to identify the sources of persistent errors (chapter 4). (shrink)

The General Relativity understands gravity like inertial movement of the free fall of the bodies in curved spacetime of Lorentz. The law of inertia of Newton would be particular case of the inertial movement of the bodies in the spacetime flat of Euclid. But, in the step, from general to particular, breaks the law of inertia of Galilei since recovers apparently the rectilinear uniform movement but not the repose state, unless the bodies have undergone their collapse, although, the curved spacetime (...) becomes flat and the curved geodesies becomes straight lines. For General Relativity is a natural law, within of a gravitational field, the accelerated movement of the bodies, that leads to that a geometric curvature puts out to the bodies in such geodesic movement. In this paper this error of General Relativity, like generalization of the law of inertia of Galilei, is examined and it is found that it is caused by suppression of mass and force that allows conceiving acceleration like property of spacetime. This is a mathematical and non-ontological result. Indeed, mass and force are the fundament that the gravitational acceleration is independent of the magnitude of mass of the bodies but gravity not of the mass and the gravitational force. The action of the gravity force, on inertial and gravitational masses of a body, produces mutual cancellation during its free fallen but too its weight when this cease. By means of the third law of Newton it shows that gravity is a force since weight is caused by gravity. (shrink)

The General Relativity understands gravity like inertial movement of the free fall of the bodies in curved spacetime of Lorentz. The law of inertia of Newton would be particular case of the inertial movement of the bodies in the spacetime flat of Euclid. But, in the step, of the particular to the general, breaks the law of inertia of Galilei since recovers the rectilinear uniform movement but not the repose state, unless the bodies have undergone their union, although, the curved (...) spacetime becomes flat and the curved geodesies becomes straight lines. For General Relativity is a natural law, within of a gravitational field, the uniform accelerated movement of the bodies, that leads to that a geometric curvature puts out to the bodies of the repose state for animate them of the movement of free fallen. In this paper this error of General Relativity, like generalization of the law of inertia of Galilei, is examined and it is found that it is caused by suppression of mass and force that allows conceiving acceleration like property of spacetime. This is a mathematical and non-ontological result. Indeed, mass and force are the fundament that the gravitational acceleration is a constant value for all the bodies, independently of the magnitude of mass but not of the mass and the gravitational force. The action of the gravity force, on inertial and gravitational masses of a body, produces mutual cancellation during its free fallen. In addition, by means of the third law of Newton it demonstrates that gravity is a force since weight is caused by gravity force. (shrink)