Questions about relativistic theory of gravity. General relativity describes gravity as a geometrical property of space and time.
Questions tagged [general-relativity]
266 questions
17
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1 answer
Are astronomers researching or trying to find signs of worm holes?
In many movies and in the popular culture wormholes are often referenced, as well as "faster than light travel", which seems almost to be the same thing, is possible.
Are astronomers seriously considering and researching this phenomenon? What could…
bogen
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5
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1 answer
Relativistic Mercury orbit around the Sun
My question is the following,would the scalar of precession of Mercury orbit be the same if Mercury orbited Sun in the oposit direction?
Janko Bradvica
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4
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1 answer
About the strange case of Bonnor beams
Bonnor beams are light beams of infinite extent and small thickness. They have an associated spacetime (related to their energy and momentum which shapes the stress-energy tensor) of which Bonnor calculated the characteristics.
If two of these beams…
Deschele Schilder
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3
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2 answers
Is it coincidence that Einstein predicted exactly twice the outcome of Newton for the gravitational deflection of light?
During a solar eclipse Sir Arthur Eddington measured the deflection of star light by the Sun. Einstein predicted a deflection of 1.74 arc seconds, but according to Newton the deflection should have been 0.86 arc seconds. So is it a coincidence that…
Marijn
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2
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3 answers
Do you need to understand the detailed mathematics of general relativity to be a professional astronomer?
Could I become an astronomer by understanding how to use the main results of general relativity such as cosmological redshift or would I need to understand the whole theory?
user50623
2
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0 answers
Order of magnitude of this phase space invariant?
So I wanted know the order of magnitude of this phase space invariant (equation $3.31a$ )$R$ in our universe (FLRW metric):
$$R = \int_{p} \frac{\mathcal{N}(x,p,t)}{\mathcal{E}} dp_x dp_y dp_z$$
where $\mathcal{N}(x,p,t)$ is the phase space…
More Anonymous
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2
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2 answers
What does "negligible mass" mean in the formulation of geodesics equation?
Wikipedia says:
According to Einstein's theory of general relativity, particles of
negligible mass travel along geodesics in the space-time.
Does that "negligible mass" only refer to particles or objects like a spacecraft, whose mass are…
user7843
2
votes
3 answers
Time measurement outside solar system?
The sun is used to determine and measuring time in our solar system. What if we were to travel outside the solar system i.e. to interstellar space, or other galaxies and other celestial bodies (out of our solar system). How would we keep a tab on…
FlyingBird
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vote
2 answers
Why can't we travel faster than light? And is the theory of relativity absolutely flawless?
Why can't we travel faster than light? And is the theory of relativity absolutely flawless?
Kevin Lee
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1
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1 answer
Age and relativity
This is a question, where I start with some assertions:
Try to consider the universe as a four-coordinate system, x,y,z,t where t is time and where we view a change in t as a change in position, and as a velocity in the same way as any other change…
frodeborli
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Can we say space contracts around a massive object in space?
Space expands on a cosmic scale. It makes objects accelerate away from each other, as observed.
Can we say, by the same token, that space contracts around massive objects in space, with the consequence that objects accelerate towards each other…
Deschele Schilder
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-4
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2 answers
What is the minimum amount of dark matter to start controlled nuclear fusion in nature?
In large spaces where there is a lot of dark matter, Stars are born in groups and not alone, so what is the minimum amount of dark matter to start controlled nuclear fusion in nature?
z.10.46
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