*Ta-Pei Cheng*

- Published in print:
- 2009
- Published Online:
- February 2010
- ISBN:
- 9780199573639
- eISBN:
- 9780191722448
- Item type:
- chapter

- Publisher:
- Oxford University Press
- DOI:
- 10.1093/acprof:oso/9780199573639.003.0004
- Subject:
- Physics, Particle Physics / Astrophysics / Cosmology

After a review of the Newtonian theory of gravitation in terms of its potential function, we start the study of general relativity (GR) with the introduction of the equivalence principle (EP). The ...
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After a review of the Newtonian theory of gravitation in terms of its potential function, we start the study of general relativity (GR) with the introduction of the equivalence principle (EP). The Weak EP (the equality of the gravitational and inertial masses) is extended by Einstein to the Strong EP, the equivalence between inertia and gravitation for all interactions. This implies the existence of “local inertial frames” at every spacetime point. In a sufficiently small region, the “local inertial observer” will not sense any gravity effect. The equivalence of acceleration and gravity means that GR (physics laws valid in all coordinate systems, including accelerating frames) must necessarily be a theory of gravitation. The strong EP is used to deduce the results of gravitational redshift and time dilation, as well as gravitational bending of a light ray.Less

After a review of the Newtonian theory of gravitation in terms of its potential function, we start the study of general relativity (GR) with the introduction of the equivalence principle (EP). The Weak EP (the equality of the gravitational and inertial masses) is extended by Einstein to the Strong EP, the equivalence between inertia and gravitation for all interactions. This implies the existence of “local inertial frames” at every spacetime point. In a sufficiently small region, the “local inertial observer” will not sense any gravity effect. The equivalence of acceleration and gravity means that GR (physics laws valid in all coordinate systems, including accelerating frames) must necessarily be a theory of gravitation. The strong EP is used to deduce the results of gravitational redshift and time dilation, as well as gravitational bending of a light ray.

*Nathalie Deruelle and Jean-Philippe Uzan*

- Published in print:
- 2018
- Published Online:
- October 2018
- ISBN:
- 9780198786399
- eISBN:
- 9780191828669
- Item type:
- chapter

- Publisher:
- Oxford University Press
- DOI:
- 10.1093/oso/9780198786399.003.0011
- Subject:
- Physics, Particle Physics / Astrophysics / Cosmology

This chapter embarks on the study of Newton’s law of gravitation. It first discusses gravitational mass and inertial mass, a measure of the ‘resistance’ of the point particle to an applied force. The ...
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This chapter embarks on the study of Newton’s law of gravitation. It first discusses gravitational mass and inertial mass, a measure of the ‘resistance’ of the point particle to an applied force. The numerical value of the inertial mass of a body can in principle be obtained from collision experiments by assigning to a reference body a unit inertial mass of one kilogram or, more rigorously, one ‘inertial kilogram’. Next, the chapter considers the ratio of gravitational and inertial masses. It considers that, in the absence of friction, all objects, no matter what their inertial mass, or the nature of their constituents, or the internal energy or cohesive forces of their constituents, fall in the same way in an external gravitational field. Finally, this chapter studies Newton’s gravitational force and field, as well as the Poisson equation and the gravitational Lagrangian.Less

This chapter embarks on the study of Newton’s law of gravitation. It first discusses gravitational mass and inertial mass, a measure of the ‘resistance’ of the point particle to an applied force. The numerical value of the inertial mass of a body can in principle be obtained from collision experiments by assigning to a reference body a unit inertial mass of one kilogram or, more rigorously, one ‘inertial kilogram’. Next, the chapter considers the ratio of gravitational and inertial masses. It considers that, in the absence of friction, all objects, no matter what their inertial mass, or the nature of their constituents, or the internal energy or cohesive forces of their constituents, fall in the same way in an external gravitational field. Finally, this chapter studies Newton’s gravitational force and field, as well as the Poisson equation and the gravitational Lagrangian.

*Ta-Pei Cheng*

- Published in print:
- 2015
- Published Online:
- August 2015
- ISBN:
- 9780199693405
- eISBN:
- 9780191803130
- Item type:
- chapter

- Publisher:
- Oxford University Press
- DOI:
- 10.1093/acprof:oso/9780199693405.003.0004
- Subject:
- Physics, Particle Physics / Astrophysics / Cosmology

After a review of the Newtonian theory of gravitation in terms of its potential function, this chapter starts the study of general relativity (GR) with the introduction of the equivalence principle ...
More

After a review of the Newtonian theory of gravitation in terms of its potential function, this chapter starts the study of general relativity (GR) with the introduction of the equivalence principle (EP). The weak EP (equality of gravitational and inertial masses) was extended by Einstein to the strong EP (equivalence between inertia and gravitation for all interactions). This implies the existence of “local inertial frames” at every spacetime point. In a sufficiently small region, a “local inertial observer” will not sense any gravitational effect. The equivalence of acceleration and gravity means that GR (with physics laws valid in all coordinate systems, including accelerating frames) must necessarily be a theory of gravitation. The strong EP is used to deduce results for gravitational redshift and time dilation, as well as gravitational bending of a light ray. The operation of GPS is shown to depend crucially on relativistic time dilation effects.Less

After a review of the Newtonian theory of gravitation in terms of its potential function, this chapter starts the study of general relativity (GR) with the introduction of the equivalence principle (EP). The weak EP (equality of gravitational and inertial masses) was extended by Einstein to the strong EP (equivalence between inertia and gravitation for all interactions). This implies the existence of “local inertial frames” at every spacetime point. In a sufficiently small region, a “local inertial observer” will not sense any gravitational effect. The equivalence of acceleration and gravity means that GR (with physics laws valid in all coordinate systems, including accelerating frames) must necessarily be a theory of gravitation. The strong EP is used to deduce results for gravitational redshift and time dilation, as well as gravitational bending of a light ray. The operation of GPS is shown to depend crucially on relativistic time dilation effects.

*Alvaro De Rújula*

- Published in print:
- 2018
- Published Online:
- February 2020
- ISBN:
- 9780198817802
- eISBN:
- 9780191859366
- Item type:
- chapter

- Publisher:
- Oxford University Press
- DOI:
- 10.1093/oso/9780198817802.003.0007
- Subject:
- Physics, Particle Physics / Astrophysics / Cosmology

A discussion of the “carriers” of the basic forces of nature and the way they “work.” Electrical charges and their interaction with photons (QED). Gravitons and the identity of inertial and ...
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A discussion of the “carriers” of the basic forces of nature and the way they “work.” Electrical charges and their interaction with photons (QED). Gravitons and the identity of inertial and gravitational masses. Intermediate vector bosons and the weak interactions. Gluons and the “chromodynamic” interactions (Quantum Chromodynamics: QCD). Adding electric charges and “colored” chromodynamic charges. Confinement in QCD.Less

A discussion of the “carriers” of the basic forces of nature and the way they “work.” Electrical charges and their interaction with photons (QED). Gravitons and the identity of inertial and gravitational masses. Intermediate vector bosons and the weak interactions. Gluons and the “chromodynamic” interactions (Quantum Chromodynamics: QCD). Adding electric charges and “colored” chromodynamic charges. Confinement in QCD.