All Questions
Tagged with gravity orbital-motion
182
questions
19
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3
answers
1k
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Can perfectly stable orbits exist in GR?
Defining "stable orbit" between two bodies as one where, in the absence of other bodies or non-gravitational forces, the distance stays between some value pair $r_{min}>0$ and $r_{max}$. ...
- 343
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0
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30
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Better equations for modeling and simulating a halo orbit?
I'm trying to model a halo orbit at low altitude (10m from surface). The satellite is using propulsion to trace the circular halo path. It looks like this "from the top" (the blue ball is ...
- 231
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votes
1
answer
85
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Questions about speed of gravity [duplicate]
If gravity "travels" at $c$, and the sun is travelling "forward", does it mean the planets are actually orbiting various points "behind" the center of the sun? Does it ...
1
vote
1
answer
122
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Which of Kepler's laws would remain true if the force of gravity were proportional to the product of squares of each masses?
I was asked this question recently on which of the Kepler's Three law would remain if we changed the force of gravitation to be proportional to the product of squares of each masses instead of just ...
2
votes
1
answer
50
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How to relate a gravitational plane wave to the GW from a binary system?
I have two different forms of gravitational waves that I am trying to reconcile.
A monochromatic GW with angular frequency $\Omega$ propagating in the $\textbf{n}$-direction can be expressed as
$$ ...
- 1,751
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0
answers
55
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What is the locus of the velocity vectors of a spaceship moving in some distance from a black hole?
Someone with a background in mathematics and limited knowledge of physics asks the following question:
Starting from rest, a spaceship is momentarily pushed with a specific amount of kinetic energy in ...
- 159
3
votes
0
answers
56
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Approximation of Nearly Circular Orbit by a Precessing Ellipse
I am self-studying the 3rd edition of Goldstein's Classical Mechanics and have hit a roadblock when working a problem (Chapter 3, Problem 20). The problem asks us to consider a planet of mass $m$ ...
- 373
2
votes
1
answer
131
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What is the MOND elliptical orbit speed equation?
According to MOND, beyond $~a_0~$, the circular orbit speed is derived with $~v = (GMa_0)^{1/4}~$. That gives a constant orbit speed regardless of radius, as in flat rotation curves.
But accelerations ...
- 85
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votes
4
answers
244
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Can Schwarzschild acceleration be written in exact form as a function of position and velocity vector?
For the special case of only one massive point-shaped or spherically symmetric non-rotating body and a small "test mass" body under general relativity the movement of that small body is ...
- 729
3
votes
1
answer
94
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In a binary black hole system, can one of the black holes get ejected before merging in some contexts?
As it is said here (https://physicsworld.com/a/couple-emerges-from-trio-of-supermassive-black-holes/) a system of two orbiting black holes could disrupt the gas and stars at the center of the galaxy ...
- 2,462
3
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2
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368
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How strong of a gravitational field do you need for a projectile to make a full loop?
How strong of a gravitational field do you need for a projectile to make a full loop? By full loop I mean it curves once around the by dot, and then it ends up on the same trajectory as it was one ...
- 2,908
1
vote
2
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484
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Conditions for the Virial theorem
I've been investigating the Virial Theorem, and I've found different conditions, some more restrictive than others, for it to be applicable to a given system. According to my professor, said theorem ...
- 1,616
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3
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140
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Do objects with non-uniform shapes and mass distributions rotate as a result of gravitational attraction?
I was thinking about orbital mechanics this morning and a question arose: do objects with non-uniform shapes and mass distributions rotate as a result of gravitational attraction?
Thinking through the ...
- 822
5
votes
1
answer
547
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Lagrange Points in General Relativity
In the Newtonian formulation of celestial mechanics it makes sense that a Lagrange point is a point where two gravitational forces of two bodies (and the centrifugal force of the rotating reference ...
- 648
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1
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Distribution of Earth's mass and its role in the nodal precession of satellites?
From what I have read and understood so far, the nodal precession of a satellite in low Earth orbit is caused by the bulge equatorial of the Earth (caused by its rotation on itself) which moves the ...
