Questions regarding the attractive force which exists between any two bodies of matter.

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5
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2answers
2k views

how can a supermassive black hole cause so much energy to enlighten its matter when its massive gravity prevents light to escape?

to cite this german newspaper: Das Materie-Monster sitzt den Angaben zufolge im Herzen der 42 Millionen Lichtjahre entfernten Polarring-Galaxie NGC 660, deren Aktivität innerhalb weniger Monate ...
3
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0answers
44 views

Do differentials in the Earth's density cause the flyby anomaly?

The flyby anomaly is an occasional, unpredictable, and as yet unexplained discrepancy in acceleration of satellites when they pass close by the Earth. It causes an increase of up to 13 mm/s during ...
5
votes
3answers
166 views

How fast would Earth need to rotate to fling someone off due to centrifugal force?

If Earth started spinning fast enough, would the centrifugal force eventually overcome Earth's gravity enough enough to fling someone (let's assume 75 kg) into orbit or into space? If so, how fast ...
4
votes
2answers
104 views

Are white dwarf stars supported by proton degeneracy as well?

In general, fermions form a degenerate gas under high density or extremely low temperature. It's clear that white dwarf stars are supported by electron degeneracy pressure. However, there are still a ...
3
votes
1answer
64 views

Why don't globular clusters flatten with a galactic disc?

Globular clusters lie in the galactic halo, outside of the disc. However, galaxies are more or less a collection of material and objects — why is it, then, that most stars form a plane due to the ...
1
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1answer
69 views

How close would merging black holes have to be to feel gravitational waves? [duplicate]

Recently LIGO discovered gravitational waves caused by two black holes that were orbiting each other, and then collapsed into one black hole. A few months later, we find out that this actually happens ...
2
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2answers
100 views

Could this three moons system be stable?

In my fictional world I have selected all parameters to maximize the Hills Sphere of my planet. The planet has three times Earth's mass and it is located in 2 AU from its star that's 1.4 times more ...
3
votes
2answers
127 views

Techniques for locating origin of gravitational waves

The gravity wave detections (GW150914 and GW151226) have both been ambiguous in their exact position, the LIGO papers (GW150914 and GW151226) give no precise information about the location of the ...
8
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2answers
169 views

Is it possible for a moon to continuously have a side facing its star whilst orbiting a planet?

For example; is there any possibility for the moon to always have a side facing the Sun whilst orbiting Earth? And if so then what would the day cycle be like?
-5
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1answer
86 views

Can a gas giant be hollow?

Let's think of Saturn, because of its density. Can there be a place near the center of the planet where the gravity upwards is more than towards the center, and with an atmosphere that is more ...
1
vote
2answers
86 views

Higgs Bosons in the centre of Black holes or extremely large stars [closed]

With the discovery of the Higgs Boson as the mass carrier, what is the possibility at the centre of a black hole being so dense and gravity so infinite that the structure of a proton or neutron are ...
0
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1answer
61 views

Would the (orbitting) speed of the earth change if suddenly the sun disappear and the earth is thrown into space?

Usually an orbit is considered as an acceleration. So fe the earth has a speed of about 100.000km/h around the sun. Now I think there is some relativity involved, so from which point of view shall we ...
0
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2answers
112 views

Could asteroid mining affect gravitational balance?

I'm just a guy who is interested in all topics around space, so forgive me if it is a dumb question. I have read some things about asteroid mining in the past and I think it's a really interesting ...
1
vote
0answers
60 views

Theoretically could the expansion of the universe affect acceleration due to gravity?

I was wondering if theoretically the universe expanding affects speed or acceleration due to gravity, compared to if space weren't accelerating. The way I have it in my head, something is falling ...
3
votes
2answers
178 views

Can I leave a planet without achieving escape velocity?

I know that if you exceed orbital velocity, you will never fall-back to the planet. My question is not about orbits. It's about brute-force propulsion to achieve altitude. I'm using an ...
0
votes
1answer
151 views

LIGO gravitational wave chirp signal frequency

This question is about the LIGO gravitational wave signals' frequency. The signals start from about 35 Hz to peak at about 250 Hz, giving evidence of gravitational waves. The question is about the ...
8
votes
1answer
917 views

How can neutron stars have gaseous atmospheres?

Neutron stars can have small atmospheres. However, they also have extremely strong gravitationally pulls. Shouldn't the all the gas molecules be drawn to the star's surface, and become solids under ...
2
votes
2answers
117 views

Solar Pressure and Gravity

I recently read some articles and pages on Solar Sails, and the possibility of using lasers to propel spacecraft, and I had a relatively outlandish idea. Would it be possible for a star to be ...
0
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0answers
48 views

Does a self-gravitating gas necessarily develop turbulence?

Though we may still doubt the exact driving mechanism of turbulence in each particular case (ISM, MC, circum-BH/-stellar discs, atmospheres...), can I say that in a sphere of dark matter particles no ...
-5
votes
1answer
59 views

Could gravity be the 4th dimension? [closed]

According to Michio Kaku, in his book Hyperspace, he said that in this Hyperspace, there exist a total of 10 dimensions that govern the laws of physics. Is it possible that we too live in a Hyperspace,...
3
votes
1answer
154 views

Why does Titan have lower surface gravity than the Moon when Titan is more massive?

Reading on Wikipedia I saw that Titan is 80% more massive than the earth's moon but has only 85% the surface gravity. Why is this?
10
votes
1answer
1k views

Can dark matter be found in the shape of planets, galaxies etc.?

If dark matter has gravity just like normal matter, does that mean it can also form planets, solar systems and so on? Any answer will be appreciated.
1
vote
1answer
162 views

Could we verify the structure of a black hole by observing an orbiting object?

Can we determine the physical structure of a black hole by observing its gravitational effect on objects in orbit? There are three possibilities that I see, and would like to test: Singularity at ...
3
votes
1answer
73 views

How does an absolute horizon form before the apparent horizon?

If I understand it correctly, the apparent horizon is the boundary between where light directed outwards will move outwards, and light directed outwards will move inwards. Even if light is moving away ...
3
votes
1answer
55 views

gravitational time dilation multiple sources

I wondered how time would be dilated for an object in the middle of 2 black holes, however https://en.wikipedia.org/wiki/Gravitational_time_dilation only provides a formula for one source of gravity ...
0
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1answer
77 views

How does dark matter interact with black holes?

Is dark matter trapped near / in black holes, like regular matter is, or does something different happen with dark matter?
0
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1answer
104 views

Does Pi change when gravity changes [closed]

Will Pi have the same value on the surface of say Jupiter, compared to the value of PI on Earth. Or does Pi vary with gravity?
1
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2answers
31 views

How does gravity affect spacetime [closed]

Scientists say that gravity warps space and time. They also say that the more gravity there is the slower time moves. Why and/or how does gravity do this.
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5answers
7k views

How does gravity really work

I am only 12 years old and I'm constantly wondering and trying understand how gravity really works. On YouTube everyone always talks about objects warping space time around themselves and uses the ...
1
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1answer
111 views

How is mass curving spacetime?

In the GR Einstein's interpretation was in terms of a deformation of the geometry of the space ending in a curvature of spacetime. I've thought that mass could do this by interacting with other mass ...
4
votes
1answer
96 views

What star system/Galaxy did LIGO observe the gravity wave?

Are there any coordinates for the Black Hole system, or galaxy for which the LIGO observations, observed the gravity wave? Any coordinates of the black hole system for which the gravity wave signal ...
4
votes
1answer
66 views

When black holes such as those detected by LIGO merge, in what ways does the Schwarzschild Radius warp?

I was reading the paper about LIGO's detection of gravitational waves, and I wanted to know what the Schwarzschild Radius did. For example, I feel like the simulation here is oversimplified, and that ...
1
vote
2answers
129 views

How can a supernova cause a gravitational wave?

With the recent results of LIGO, I read a lot how limited the detection capabilities where and how one could only expect to measure the most extreme events like black hole mergers and supernovae. I ...
1
vote
2answers
72 views

What are gravitational waves actually? [duplicate]

I read about the LIGo experiment recently, but i didn't understand their significance. Although, it's clear to me that the gravitational waves do exist and are caused by large accelerating bodies in ...
10
votes
1answer
184 views

Will gravitational waves too far away ever reach us?

Gravity is the curvature of spacetime, and its effects travel at lightspeed. However, space is expanding; eventually, light from distant galaxies will become more and more redshifted, and we will no ...
1
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1answer
60 views

Procession of the Equinox

I just learned about procession of the equinox, i.e. the Earth's axis tilts one degree every 72 years. And it takes 72 years/degree x 360 degrees = 25,920 There are many theories to this, i.e. ...
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votes
2answers
85 views

What is the current state of gravity in the vacuum of space? [closed]

Is Gravity in the vaccum of space decelerating or exspanding? please explain why,when and how in detail, Along with a credible reference. If Science has not concluded either please give a reference as ...
6
votes
5answers
431 views

Are black holes really singularities?

Can't black holes just be super dense objects? They could still be black (having the color of black never really required special physics, after all) and have a really strong gravitational field. If ...
1
vote
1answer
140 views

How did LIGO verify that the gravitational waves originated 1.3 billion years ago from two specific black hole collision? [duplicate]

So they finally found gravitational waves. That's cool and I trust is the case, but how did they confirm it originated 1.3 billion years ago and that two blackholes merging caused it and what ...
28
votes
6answers
6k views

What did LIGO Actually See? (Gravitational waves discovery)

I am trying to find an original video/image of what LIGO actually saw, but all I can find is artist renditions of gravitational waves.
2
votes
2answers
129 views

Could gravity waves be used to confirm the existence of a ninth planet?

Shortly after the news of the discovery of gravity waves, my physics professor explained the significance of the discovery by comparing it to a medical X-ray machine. He said that gravity waves can be ...
4
votes
2answers
125 views

Why do Earth and moon move apart but binary black holes move closer?

According to the accepted answer on Is the moon moving further away from Earth and closer to the Sun? Why?, the moon is receding from Earth because tidal forces and friction cause energy to be lost. ...
8
votes
1answer
110 views

Spinning black hole vs non spinning black hole

Does a spinning black hole have a stronger gravity than a non spinning one.After all, a spinning black hole is stretching space-time more, so does that make a difference is gravity?
5
votes
1answer
269 views

What do gravitational waves allow us to understand?

Before reading this question, you should read this paper. From what I understood, we managed to detect gravitational waves for the first time. Is this discovery going to help us understand ...
3
votes
2answers
100 views

Why does mass naturally move closer toward's the center of other masses?

If general relativity is understood to mean that mass curves space such that objects are still traveling in a straight line, why does mass naturally move closer toward's the center of other masses?
12
votes
3answers
1k views

Existence of gravitons?

For a lot of my uninformed life, I have doubted the existence of gravitons or even that gravity is an actual "force" (like electromagnetism). This is because my vision of general relativity was that ...
7
votes
3answers
111 views

Precision of geocentric gravitational constant

I am looking for an answer as to why the geocentric gravitational constant, μ, defined as the product of the gravitational constant, G, and the mass of a body (earth in this case), M, can be ...
1
vote
1answer
62 views

Why is it strange that outer stars are travelling with the same speed as inner while the total mass is also increasing?

Astronomers say that it's strange that the outer stars of a gallaxy are travelling with the same speed as the inner stars. Therefor they introduced dark matter to solve this strangeness. The theory ...
0
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1answer
34 views

Is their any clue where gravitons come from?

Everything which has mass has gravity. Some theories hypothesis that gravitons are responsible for that, but do they have any clue where they come from? Like gluons are interacting between quarks and ...
0
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1answer
121 views

what is gravitational force?

Gravitational force is particle or wave? I know that gravitation depend of the mass and the rotation speed but what is the transmission medium of this wave the same like transmission medium of the ...