Gravity is an attractive force that affects and is effected by all mass and - in general relativity - energy, pressure and stress. Prefer newtonian-gravity or general-relativity if sensible.

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Can the gravitational force be affected by another force? [closed]

Can the gravitational force be affected by another force? If yes, then like what? I was reading about conservative forces and was given the gravity force as an example stated that one of the reasons ...
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Gravity difference on earth?

Would gravity on earth be any different if the earth were in intergalactic space rather than interstellar space?
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Standing waves and acoustic levitation

i am doing a new personnal project about acoustic levitation with standing waves into ambiant air using a piezo ultrasonic tranceiver and a reflective pannel. I modelised both of the emission and the ...
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75 views

Non-locality of gravitational energy

Gravitational energy is non-local which is essentially because of the equivalence principle. The equivalence principle says that you can always transform your frame so that you feel like in a ...
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328 views

Can an observer know what is the source of gravity?

There's an observer in a closed room without windows under an influence of gravity force. Can he determine what is the source of gravity - whether it's a spinning motion, acceleration or huge mass ...
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Centre of gravity: Adjusting position

If an object is freely suspended from a pivot, why does the centre of gravity fall directly below that pivot? Would this be the same in non-uniform gravitational fields?
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39 views

A question gravitation and magnetism? [closed]

Suppose I have a magnet and I put a piece of iron next to it, then the magnet will attract it. Now if I put a piece of wood in front of the magnet and the piece of iron, the iron will not get ...
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Two places having same gravitational acceleration - Do they also have same curvature of space time?

If there are two places (possibly on/above two different planets) having same gravitational acceleration (g), would it imply that the two places have same extent of space time curvature and will have ...
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42 views

Why is the matter orbiting a black hole in the shape of a disk? [duplicate]

More generally, if a blackhole is a singularity...a point in space...why is matter only circling in a flat disk-like region. It would seem to me matter would circle it in a sphere surrounding the ...
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Is there a path to go from GR, to Gravitational Waves, to Gravitational Particles (Gravitons), to Quantum Gravity?

The articles on the subject often say : a part of the mass of the 2 celestial bodies became energy for gravitational waves after merging : E(gravity waves) = (M1 + M2 - M_merged).c^2 Intuitively I ...
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Why do black holes need a quantum mechanical description?

I read about black holes, about the Schwarzschild metric, Einstein field equations and their solution in the vacuum for a spherical body. I understood black holes are object whose gravity is ...
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93 views

Distance from Earth where gravity becomes negligible

This is a basic little problem I thought up when trying to remember some physics, and I wanted to see if it's at all correct: trying to figure out the distance from earth where gravity becomes ...
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Why do water droplets not form on large openings such as pipes?

When you have an object with a small opening, such as a pipette, water droplets form and hang easily. However, when you have a larger opening such as a pipe, the same water droplets do not form. Is ...
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Theoretical Possibility of “Opposite” Gravitational Mass? [duplicate]

This is an unusual idea that I have been entertaining for some time, and I can't find anything about it online. However, it is so simple that someone must have conceived it before. First, I will ...
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28 views

Can a tidally locked planet have a horizontal rotational axis?

Is it hypothetically possible for a planet to be both tidally locked, and still have a rotation "horizontally"? Where the substellar point would in effect be like the point of a top, spinning and yet ...
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42 views

What is the relationship between the flow rate of time and gravitational field?

I have heard, qualitatively, about the fact that time's rate of flow slows when the gravitational field is "strong". Here I am looking for some more rigorous descriptions of this phenomenon. My first ...
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230 views

Gravitational self-interaction

Today, someone asked me why "the warped space-time warps itself" (he read it in Kip Thorne's: The Science of Interstellar). I guess this is related to the gravitational self-interaction. But I don't ...
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If mass increases as velocity increases, does gravity increase as well? [duplicate]

The way I understand it, velocity and mass are tied together with relativity. As I increase in velocity, I increase my mass until my mass is so great that it would take more energy than the entire ...
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41 views

Can the KLT low-energy limit relations be obtained without string theory?

The KLT (Kawai-Lewellen-Tye) relations roughly say that -at the tree level- closed string amplitudes equal open string amplitudes squared and in the low-energy limit this becomes a "Gravity = Gauge ...
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Does orbital motion cause rotation?

Assume the moon was flying freely in space, and not rotating at all. If if then happened to pass earth at just the right distance and velocity to fall into orbit, would its absolute rotation be ...
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34 views

Can a micro black hole hover above a regular black hole?

So let's say you have a black hole $A$, that is small enough for its gravity to be very small, but has strong hawking radiation, and larger black hole, $B$, with very small hawking radiation, but ...
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1answer
65 views

When we spin and feel our arms fly, is it the effect of gravity?

If accelerating reference frames can be treated as normal inertial reference frames but with gravity, then for a rotating reference frame, is the centrifugal force = gravity? More specifically, I was ...
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Is it possible that dark-matter is composed of a large number of neutrinos from the big bang? [duplicate]

They seem to have all the properties of dark-matter (massive, with no electromagnetic interaction). Could it be that many of the neutrinos produced since the big bang have formed massive neutrino ...
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Derivation for the temperature of Reissner-Nordström (charged) black hole

A lot of the text for this is from "How does one correctly interpret the behavior of the heat capacity of a charged black hole?" but this concerns a different question. The Reissner-Nordström black ...
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Is the energy released by gravitional waves kinetic energy or converted rest mass?

It is said that at the binary black hole collision LIGO detected recently, the energy equivalent of 3 solar masses has been released. Since no matter can escape a black hole, the only source I can ...
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Can solar flares affect gravity?

Can a large eruption of solar flares on our sun change the effects of its gravity ever so slightly, and is it possible to measure these changes with the equipment we have today.
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113 views

Does light have mass? [closed]

Does light have mass? If yes, will it exert force? If no, then how are light particles are travelling at light speed? If light doesn't have mass how is it attracted by gravitational force (black ...
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68 views

Is this actually how gravity is illustrated? [duplicate]

In general relativity, gravity is said to be caused by the curvature of space time. And there are examples that illustrate gravity such as this video https://www.youtube.com/watch?v=MTY1Kje0yLg, and ...
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Gravity with more than one metric tensor

As weird as it sounds, yes, there are gravity theories with more than one metric tensor. This is called bimetric gravity. My question to those who have encountered bimetric gravity before: a) ...
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85 views

Can a system be engineered to cause a standing wave resonance with gravity waves? [closed]

Thank you Docscience for helping me adjust my question in a better direction. My interest has been sparked by getting Into the chapter of waves in physics class and of course the new discovery of ...
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74 views

Trouble in understanding spacetime

I have a problem in understanding spacetime. What i understood from the conversion of time to distance is that the interval between any two events is always the same for any observer. But how is that ...
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199 views

Why doesn't gravity fit into quantum theory?

Before you read, I want to point out that I probably don't know nearly as much as you guys about quantum theory, even though I love learning about it, so I would prefer explanations in relatively ...
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68 views

Gravity and elliptical orbits

All orbits are elliptical and special orbits are circular (like when both bodies have the same mass or when the second body's mass is negligibly small). In a circular orbit centrifugal force (which I ...
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348 views

How does the curvature of spacetime exert a force on a stationary object?

I understand the idea that, when spacetime is warped by a large mass, objects that try to travel in straight lines instead move along curved geodesics, something Newton would describe as an ...
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88 views

What is the speed of gravity in a Schwarzschild metric?

The question "How does gravity escape a black hole?" has been asked, but the responses are not fully satisfying. Frederic Brunner gives a startling intuitive answer: "Gravitational attraction ... is ...
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How does gravity affect different bodies? [duplicate]

To my understanding,the force of gravity increases as the mass of the body increases (ex. the moon has less gravity than the earth). So, intuitively, I would come to assume that the force of gravity ...
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29 views

Space/time elasticity and state changing

What happens to a particular section of space/time that has been bent due to a large gravitational force that has passed it by? Does it "snap back" to it's original state. Is it permanently bent? Is ...
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42 views

Is my mass relative?

Mass is said to be a source of gravity (I think:p), but if I were to travel into space. Would it change with respect to someone on earth? Since the gravity changes in space, but does it affect the ...
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Can curved space also cause repulsion? [duplicate]

Usually curved spacetime looks like it causes objects to attract to each other. But is the opposite also possible? For instance if I twist/curve a towel in one direction it is getting smaller but in ...
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8answers
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Short of collision, can gravity itself kill you?

Imagine that you are falling into object with huge gravity (i.e. black hole) that does not have any atmosphere. The question is - before you hit the ground, can the gravity itself (which would be ...
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Earth's gravitational waves? Measurable?

Why don't they measure Earth's gravitational waves which has stronger effect holding us on planet and sounds to me maybe stronger instead of measuring far black hole mass created wave 1/1000th of ...
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Gravitational wave of Big bang? [duplicate]

Questions about the g-wave caused by the big bang: 1)was there a g-wave produced? 2) when will it reach us? 3) will it be too weak for us to detect(atleast now?)?
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Calculating Potential Energy

I'm familiar with the potential energy equation, but I'm concerned with the value of 'g' in it. I know that, at sea level, earth's gravitational acceleration is 9.81 m/s/s. So I know that within the ...
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51 views

What are the implications of the LIGO results in reference to our current Cosmological models?

I was looking for some explicit information on the implications of the LIGO results or probing eras prior to the or near to the Big Bang singularity. So, my question is therefore, what, if any, are ...
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23 views

Warping of space time by objects

Note: This question may seem very silly, because I have never formally studied the physics I'm about to ask about at all, all the knowledge I have is from watching videos on YouTube out of interest or ...
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223 views

How can gravitational waves dissipate the energy carried by them? [duplicate]

I am not an expert on GR or gravitational waves but i have been reading about them and i wondered about where and how do these gravitational waves dump their energy? I read that the black hole ...
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1answer
54 views

The inside of of a black hole

I am looking for a confirmation (or correction) of my thinking about the nature of the black holes. As I am not a physicist and only a physics enthusiast, my understanding is probably very simplified ...
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2answers
55 views

Moving an object in hand back and forth creates a gravitational wave?

Does moving an object in one's hand back and forth create a wave? It creates a changing gravitation field and that propagates as a wave, right? How does that differ from a "gravitational" wave that ...
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Can Newton's law of gravitation and Einstein's GR be considered true and complete laws of gravitation? [closed]

Newton's law of gravitation and Einstein's general relativity (GR) are empirical laws of gravitation that are strong on description and prediction but lack deterministic and/or causal rigor, which ...
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Gravitational waves in other dimensions

I know this question is purely speculative, as we don't know if more dimensions do exist and also we do not know if gravity is indeed stronger in other dimensions (if they were to exist). But, one of ...