Questions tagged [tidal-effect]

The force on parts of an extended body in a non-uniform gravitational field, due to residual gravitational attraction between the overall effect on the body and the expected effect on the point in question. Tidal forces are most notably in large moons orbiting near their primaries.

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How does spaghettification work in general relativity?

Imagine a neutron star is being consumed by a black hole, so I think matter from the star is being stretched as it follows the curvature of the spacetime around the black hole. If that is the case ...
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How can I determine the total energy and power provided by an ocean wave when it reaches shore?

When an ocean wave travels to the shoreline and breaks, how much energy is released? I did some research on finding out a formula to calculate how much energy is stored and then released by ocean ...
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Falling stones attached by a string

Suppose we have two stones, one "big" (A) and one "small" (B), the smaller one over the big one at the moment of free fall. Suppose also that a string of a certain length is ...
6 votes
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Wouldn't Millers planet be ripped to shreds by extreme tidal forces?

If you can survive lava-like temperatures there is another issue for the well-being of Miller's planet from Interstellar. Time passes on the planet 61000 times more slowly than for an observer far ...
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How large can a sphere of water in low earth orbit get?

Imagine that er have a large space station in low earth orbit, and inside that space station is a large sphere of water. How large can that sphere of water get before tidal forces overwhelm surface ...
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7 answers
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Why would black hole rip me apart?

According to my understanding of General Relativity, gravity is not a force and an observer which is falling freely under the influence of gravity should be considered inertial. Now, I have come ...
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Could we be sucked up entirely by a micro black hole?

The hot question about being ripped apart in a black hole (no one can deny physics is boring!) got me thinking. If you cross the event horizon of a supermassive bkack hole, nothing noticeable will ...
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Is the gravitational tidal force equivalent to expanding space?

If you fall towards a black hole, the particles in front and the back of you, in the direction of the center, are accelerating away from you. So, seen from a freely frame, can we say that space is ...
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Problem calculating tidal deformability in GR

everyone. I am trying to calculate tidal deformation of a neutron star (NS), only keeping linear terms like it was done in Hinderer's papers https://doi.org/10.1086/533487 and https://doi.org/10.1103/...
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Tidal forces in daily situations: where to find it?

I'm trying to look for something that I'm not used to. My search is related to Tidal forces and the purpose is: making a qualitative explanation (@ High School level) of this phenomenon, using daily ...
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NASA's explanation on tidal acceleration

I've found an animation in NASA's website, illustrating tidal acceleration effect between the moon and earth. It's the forth animation from the top in this page: https://moon.nasa.gov/moon-in-motion/...
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Are there tidal forces between the solar system and the galactic centre?

Tidal forces are experienced within a system moving in free fall around a bigger object because of the different strength of gravity over the system. The difference can be calculated between the far ...
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How does Schwarzschild spacetime bend a free falling rigid body?

How does Schwarzschild space-time bend a free falling rigid body? Will it be stretched or squeezed? How much it will be modified? Can we find an effect of Lorentz contraction? When will the assumption ...
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Is the distance between the Sun and the Earth increasing?

$M$ = mass of the Sun $m$ = mass of the Earth $r$ = distance between the Earth and the Sun The sun is converting mass into energy by nuclear fusion. $$F = \frac{GMm}{r^2} = \frac{mv^2}{r} \...
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Tidal force in equivalence principle

The inertial frame of reference in a gravitational field is defined locally, but couldn't a sufficiently sensitive instrument detect tidal forces in the gravitational field and thus make the frame in ...
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Could a moon keep orbiting a planet forever?

Our Moon orbits the Earth further away each year due to the tidal forces but could there be a moon orbiting a planet where somehow keeps going further away by the tidal forces but its attracted again ...
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Smallest pool to form tidal wave

Tidal waves form in the ocean, while not in my swimming pool. I wonder what's the smallest swimming pool is like to form tidal waves. It's true that tidal wave always exists, let's assume we want a ...
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Gravity contradicting conservation of energy? [duplicate]

If we could utilize gravitational force to create energy, could gravity, being unlimited, generate unlimited energy? Consider electricity generation from tides. Since tides are due to gravity, aren't ...
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Is the Moon's rotation affected by Earth's?

There is a lot written on the moon affecting the Earth's rotation but not so much the other way around. I know that moon has its own rotation: Tidal locking is the phenomenon by which a body has ...
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How strong are the tides raised by Io on Jupiter relative to the ones raised by the Moon on Earth?

There seems to be 2 ways of calculating tidal forces that are contradictory. Either: By calculating the difference of Io's gravitational acceleration on a point on Jupiter's near side and the ...
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How long would it take for the moon to disintegrate into a ring if placed inside the Earth's Roche limit?

Wikipedia says the Earth-Moon rigid Roche limit is about 9500 km. The moon's diameter is roughly 3500 km, so say I magically teleport the moon to within 6000 km of the Earth—it's fully contained ...
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Will the increasing distance between Moon and Earth result in speeding up or slowing down of Earth's rotation period?

Problem The Moon tidally brakes Earth's rotation, and as a result distances itself away from Earth as a result of conservation of total angular momentum*. Certainly, tidal braking slows the rotation ...
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Does the moon affect the Earth's climate?

So, this morning I was talking to a friend about astronomical observations, and he told me that lately there has only been good weather when there was a full moon in the sky, which was a shame. I ...
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Is it possible to tidally lock a neutron star?

As I know, neutron stars are almost perfect sphere and no net moments, does it mean it is not possible to tidally lock it?
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What is the physical meaning of self-attraction and loading (SAL) in tides?

I came across the term self-attraction and loading (SAL) in many papers about tides. However, I don't understand the physical aspect of it. According to what I understand, self-attraction refers to ...
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Would this be a practical way to convert tidal energy into electrical energy?

Imagine a structure that is held above the water by pylons that are grounded on the ocean floor. In between these pylons is a pontoon that, when tides are rising holds and lifts a heavy weight. When ...
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Roche limit and satellites orbiting each other

Does the Roche limit apply also to two satellites orbiting each other or only to individual satellites held together by gravity? For example, I have a tungsten little ball (10 cm in diameter) around ...
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Are we slightly lighter during the day and slightly heavier at night, owing to the force of the Sun's gravity?

Using $g = \frac{Gm}{r^2}$, the force on a point mass located at 1 AU from the Sun ($m = 2 \cdot 10^{30} \text{ kg}$) is about ~0.006 N/kg. Does that mean that, e.g., a 70 kg person is ~42g lighter ...
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Tidal frequency of equatorial moon on a circular orbit (derivation)

I'm trying to learn about the phase lag angle of tidal bulges, and I often see in articles the following expression for the tidal frequency of equatorial moon in a circular orbit: $$ \chi = 2|n-\...
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More volume with more mass?

Regarding to the Schwarzschild solution, is there more volume with more mass? Lets take for example a space shuttle (spheric for simplicity) in an stationary orbit at the position $r_1$. The black ...
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Einstein equivalence principle

I know that there are two different formulations of Einstein's equivalence principle: the weak version says that the inertial and gravitational mass are equal. On the other hand the strong version ...
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How to compute the Ocean tidal effect by giving the lat+long for specific location on a website?

I am quite new in this and interested in computation of contribution of the Ocean tidal gravity. I am following the website (http://massloading.net/ondemand_form.html) to get the data but I want to ...
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Could a set of rogue double planets (binary planets) be habitable due to tidal forces?

I want to write a story about rogue double planets and was wondering if it's possible to have a double planet where either both or one of the planets are habitable due to tidal forces even if the ...
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Does a uniform gravitational field exist? Is there any acceleration in a uniform gravity field?

This question arose in the Space Exploration forum, by non-physicists, so it likely sounds naïve. The question involved the plausibility of using a very strong gravitational field to accelerate an ...
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Can you explain tides in our water bodies with respect to Theory of General Relativity and spacetime curvature?

We read everywhere that Moon's "gravitational pull" causes tidal waves. Is there any explanation of this "gravitational pull" in terms of General Relativity and curvature of ...
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Tidal forces mathematics

Let's calculate the difference in force, $\Delta F$, experienced by the rocks. Because $\Delta r$ is very small compared to $r$, $$\Delta F = F_{\text{out}} - F_{\text{in}} \approx\frac{dF}{dr}\Delta ...
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Physical effects due to the mass of the moon suddenly going to 0? [duplicate]

A gedanken experiment - imagine the moon's mass instantaneously went to 0 ; what would happen?
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Is the tide on Earth caused by curvature of spacetime

The tide on Earth appears absolutely whenever the moon is overhead. Is that tide caused by spacetime, re-curvature in space or attraction gravity?
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How does general relativity explain tides?

How general relativity explains tides using spacetime curvature? and if the full moon can affect water, inside the international space station did the ever observe small things like water droplets ...
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Derivation of Roche Limit

In calculation of the Roche limit between the two celestial body, tidal force on small mass $u$, $F_t$ is expressed approximately as $$F_t=\frac{2GMur}{d^3}$$ While deriving $F_t$, what's the reason ...
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Earth, Moon, gravitatioal pull

Does the gravitational pull that causes tides, also affect the Earth's land mass. Does it affect the atoms, molecules, is there a slight bulge to the actual Earth / Land itself?
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Do you really die if spaghettified by a black hole?

Considering gravity acts by stretching spacetime and all forces (EM, nuclear etc...) are relative to spacetime, can we then consider that regardless of how stretched you are to an observer outside the ...
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Weight dependency on the location on Earth relative to Sun

In this post a theoretical physicist says that one will weigh less at the point on the Earth closest to the Sun due to the Sun's gravity, which makes sense to me. But he also says that one will weigh ...
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Can an observer in a double tidal locked system figure out it is orbiting?

Tidal locking, when the spin rate of a body matches the orbital rate so that it always faces the other body with the same side, usually occurs for just one of the bodies in orbit. However, there are ...
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How does one calculate the tidal force in the throat of a wormhole?

If you were to attempt to open a wormhole from Earth to Alpha Centauri (4.37 LY), and its throat were to be a radius of 1m, while its mouth were to be 1.5m radius, how many newtons of force would be ...
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Tidal Forces on a Body at a Fixed Altitude

It's a thought experiment which I've been running in my mind for long in order to understand tidal forces. Any suggestions/ideas are appreciated. Assume a perfectly spherical planet with no atmosphere....
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What is the difference of gravity between lowest tides and highest tides?

I know tides are due to gravitional gradients so the difference of gravity between places does not need to be big in order to generate tides. Regardless, what difference are we talking about, ...
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Why is the orbital resonance of the Galilean moons stable?

It is well known that the orbits of Ganymede, Europa and Io are in a 4:2:1 resonance. Most online sources (including but not limited to Wikipedia) say that such an orbital resonance, along with the 3:...
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What are tidal forces inside a black hole?

It seems to me that a body under the event horizon of the black hole should not experience any tidal forces, because the singularity is not in any spatial direction from the body but in the future. As ...
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Is the lay explanation of the equivalence principle wrong?

The common explanation/trope for the equivalence principle always has something to do with you being inside an elevator or spaceship, and your supposed inability to differentiate, say, gravity from a ...

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