Tidal Definition and 160 Threads

One of the nitpicks about Interstellar the film is the tidal wave on Miller's Planet. Miller's Planet is deep in the gravity well of a monster black hole. Lot's to unpack there but the upshot is that there's a tidal wave that sweeps around the planet shaped like a tall, very steep mountain...

Ignoring global warming, the Earth will spin progressively slower. But how will global warming affect this? THEY say, LESS water, LESS slowing. > slowing spin is all about the FRICTION from the action of WATER on the LAND, when the water is gone the slowing of the spin will ceased (or at least...

Am I correct in thinking that the gravitational field of the moon passes straight through the Earth as if in a vacuum, to produce a tidal bulge on the opposite side to where the moon is, while the Earth’s much stronger field cannot actually bend or modify it as it passes through but can only add...

I read that the gravitational tidal force of a nearby blackhole can twist and tear apart stars, sometimes even in a matter of days. The 'matter of days' part peaked my interest, and I figured I would ask here before looking it up. Have we ever observed any such event in a matter of days? Is...

In order to make it as simple and non-controversial as possible, I propose a setup where inhomogeneity and change of reference frames play as little role as possible, i.e. in free space and with its center of mass comoving. I'll call that point the origin and set up my lab there. Rockets...

In the following page (which, despite examining a question that comes up in science fiction, raises valid scientific questions): http://pages.erau.edu/~andrewsa/sci_fi_projects_spring_2015/Project_1/Eilts_Mitchell/Enders%20Game%20Eilts/Enders%20Game%20Eilts/index_Eilts.html I encountered the...

And if a star is severely stretched by tidal force, how does that affect its magnetic field and the process of it collapsing at the start of a supernova?

I've heard it and I've read* it before, so I just want to make sure I understand this so I never have to wonder about it again. So, are tidal forces exactly curvature of space? Here's why I think the answer to that is yes: .I've seen a spacetime interval equation which has a coefficient on...

Consider only the Earth-Moon system, where both the Earth and Moon are spheres. A horizontal line joins the centres of the Earth and Moon. Consider a point P that lies on the surface of the Earth. The line joining P and the centre of the Earth meets the horizontal line joining the centres of the...

Hello. If its possible I'd like to find out more about tidal locking for planets orbiting K type dwarf stars. Specifically, at what distances from their host stars would exoplanets have to be to avoid becoming tidally locked. I'm specifying K dwarves because, from what I've read (see...

Hello! I was reading two things: 1) tidal locking (as explained in the Wikipedia article:https://en.wikipedia.org/wiki/Tidal_locking where it is stated that, because of internal friction caused by the body of water being attracted to the moon and deforming, the kinetic energy of the system...

Does a sort of virtual tidal effect exist inside an accelerating body (space ship) similar to the way the tidal effect is present while rest on a massive body? Or could an accurate enough 'thought experiment' measuring device figure out if it's in an accelerating ship or resting on a planet, by...

This section of the Wikipedia article on tidal locking https://en.wikipedia.org/wiki/Tidal_locking#Mechanism states: (Note : A is the earth; B is the moon) I am having trouble understanding that last "whereas" bit (bold font). It seems to me that if we consider lower and lower rotation speeds...

Given a one parameter family of geodesics, the variation vector field is a Jacobi field. Mathematically this means that the field, ##J##, satisfies the differential equation ## ∇_{V}∇_{V}J =- R(V,J,)V## where ##V## is the tangent vector field and ##R## is the curvature tensor and ##∇## is the...

It's well known that the tidal effect of the Moon on the Earth causes the Earth's rotation to slow down and the radius of the Moon's orbit to increase over time. However, the Sun also exerts a tidal effect on the Earth, which should also contribute to slowing down the Earth's spin. This raises...

I am hoping a PF participant can help me understand why the tidal forces cause the NGTS-10b planet to fall towards it's star. I more-or-less understand why our moon's tidal forces on the Earth cause the Earth's rotation period to decrease, and the conservation of angular momentum of the...

I'm having some conceptual difficulty with this; here's what (little!) I've done so far. Suppose the distance between the centres of the Earth and the moon is ##x## and that the radius of the Earth is ##r##, and let the gravitational field strength due to the moon at the near side, far side and...

Full disclosure: it's not tidal; I'm pretty sure it's a longitudinal harmonic wave - but I don't know the terminology. So today my bro and I went for a sail to Centre Island in Lake Ontario, as we often do. Lake Ontario is currently at its highest level in a long time - certainly in my...

Is General Relativity applicable in problems involving tidal gravity? For example if a system being analyzed is large enough where tidal gravity effects become apparent - suppose two distantly separated hovering observers see a freefalling object change velocity - are general relativity...

All, A couple of questions about planets around Red Dwarf Stars: I'm imagining a planet around a Red Dwarf Star...think Trappist-1...and want to know how I can prevent tidal locking for an Earth-sized terrestrial planet in such a star's habitable zone...say, 1/50th to 1/20th of an AU from the...

So, if the Earth moves slowly through a large hula hoop, sensors attached on the hoop will measure some stresses, which we might call tidal forces. The faster the Earth moves relative to the hoop the larger those tidal forces are. So, if a person falls into a black hole, there are some tidal...

How does one correct for tidal forces when (classically) simulating the orbits of solar system bodies?

How many neutron stars are binaries of other neutron stars? Hulse-Taylor binary, discovered in 1974, has orbital period of 7,75 hours. And the pulsar component rotates at 59 milliseconds. The orbit is also eccentric, from 1,1 to 4,8 solar radii. Expected to merge in 300 million years. PSR...

Hi all, this is my first post. It seems around eight years ago I was on a similar brain-wave-length as Laurence Kemball-Cook, with his idea to create a power generating flooring surface... only he had the know-how to bring the idea to market, so credit where credit is due. (though now I wonder...

[Moderator's note: This is a portion of a post originally made in another thread, which has been moved due to being off topic there.] Einstein's Equivalence principle is based on the realization that, "An observer in a windowless room cannot distinguish between being on the surface of the...

Issues about two topics were discussed in another thread. https://www.physicsforums.com/threads/do-solar-tides-affect-Earth's-orbit.933073/ The topics are: how do the lunar tides (1) cause the Earth's rotation to slow down, and (2) cause the moon to move away from the Earth. This thread is...

i have been asked to show that the TGF acting on a 1kg mass, on the surface of the Moon is equal to: TGF = 2g.e^2.(a/r^3) Where; g = 9.81 e = radius of the Earth a = radius of the Moon r = distance between the centres of the Earth and Moon.

In a heavy nucleus, the balance of the Coulomb and nuclear forces is a delicate one. This can be seen in two cases: First, in oblong deformed nuclei, alpha particle emission is more likely to occur at the poles, where the Coulomb barrier is thinner, than at the waist. Second, heavy synthetic...

I have heard about a moon Enceladus. Which is powered by tidal force. I suppose this force press back and forth on the moon and friction in the core causes heat. I hope I'm right :-) Now tidal force ##F_t=\frac{2GMmr}{R^3}##, where ##G## is Gravitation constant, ##M## is mass of planet causes...

Hi, I'm new to the forum and have an idea for a novel. I can't find anything on this question so I thought I'd sign up for a forum to ask. I'm not a scientist and lack much of the higher technical knowledge. Here's my question: Most planets in close orbits (they'd have to be to support liquid...

Say I have two masses connected by an unstretched massless spring at some height above a planet with a strong gravitational field. Once I let go, both masses would follow geodesics in spacetime towards the center of the planet. Because the masses travel radially, the spring would compress and...

Homework Statement Spherical,homogeneous star with radius R orbiting black hole at distance ## r_p >>R ## .Derive the tidal force acting upon the star by dividing the star into two equal parts and making the necessary approximations. Homework Equations The tidal force equation of ## a \propto...

Dear Forum, I am filmmaker from Berlin and despite physics focus back in high school I am really bad at it. I am trying to get my head around some ideas I am working on and would kindly ask you for some tiny calculations. I hope this is OK and maybe even fun for someone here? So my questions...

Homework Statement ANY HELP IS WELCOMED[/B] The single moon of an Earth-like planet creates tides on the planet that are slowing the planet’s rotation. The planet’s rate of rotation is decreasing at a rate of 7.00 x 10-7 radians/sec/century. The mass of the planet is 6 x 1024 kg, and its...

I am a 16 year old trying to make a research paper about it for my science high school. I'd like to study how it works and whether it can be applicable to Busan, South Korea. Thank you :)

Tidal Forces: "It arises because the gravitational force exerted by one body on another is not constant across it". which implicitly implies that the acceleration is not constant on that body. Equivalence Principle: "weightlessness sensation occurs when one free falls in gravity" - which...

So tidal power plants are a thing. They harvest the energy from water moving around. That energy comes from somewhere, specifically the moon, right? So does harvesting tidal power (very very very) slowly degrade the moon's orbit? Does liquid's existence on Earth deteriorate the orbit to begin...

Homework Statement The function h(t) = 5 sin (30(t+3)) is used to model the height of tides. On a different day, the maximum height is the minimum height is -8 and high tide occurs at 5:30am. Modify function so it matches new data. Homework EquationsThe Attempt at a Solution Answer: h(t) = 8...

Can a parent body be tidally locked with a moon, so if one was standing on the planet the moon would appear in the same location in the sky day and night?

Hi, I was just watching "The Dark Knight Rises" and was reminded of a question I had about the end and Batman's flying the nuke outside Gotham where it exploded over the sea. We know tsunamis and even mega tsunamis can be produced by avalances, rock slides, and whatnot. My question is that if...

I used to think I understood this - big mistake! I've just watched a great classic Feynman lecture posted by another PF user (a superb way to spend 50 mins of you can spare the time) https://www.physicsforums.com/threads/i-found-the-best-teacher-of-physics.855335/ In that lecture, Feynman...

I have been kicking around an idea for a while about generating electricity from ocean tides. The traditional approach is to use the flow of water through a channel to turn a turbine, which essentially blocks the channel for sea life and water craft. It seems more practical to use the rise and...

My simple description of gravitational waves is that they are due to the relativistic principle of locality, i.e. the fact that the action of gravity is not instantaneous, something that you can’t see from the tidal effects in Newtonian physics. Is it correct? I've also found a comment...

While I was thinking about how tidal forces can make objects float at the surface of a planet orbiting a massive object like a black hole, the fact that any material on the Earth isn't held together by gravity only, but also by chemical bonds which give it its tensile strength came into my mind...

Homework Statement If the distance between the Earth and the Moon doubled, by what factor would the tidal forces felt on Earth decrease by? Homework Equations Not sure if there are any relevant equations F = GM1M2 / r∧2The Attempt at a Solution [/B]G = 1/d^2, if d is doubled, then G =...

I've read that tides deform the Earth's crust by about 40cm. When I try to visualize the tidal bulge approaching me and then receding away from me, it seems like the local surface under my feet would tilt slightly one way as the bulge approaches, then level out, and then tilt slightly the other...

Let's say I'm floating in space in a spaceship, and there are some stars around. Now I turn on powerful spaceship engines. This causes a huge acceleration, which causes the brightness of some stars to increase a lot. (Those stars that are up in the pseudo gravity well become bright) Does tidal...

What's the best way to explain why tidal forces for an observer free-falling through an event horizon are finite? My first thought was to say that "gravity isn't a force, it's a curved space-time". On further thought, however, it seems to me that consideration of the Rindler horizon shows...

Lets assume that a human colony wants to reform time measurement units for more practical. Reasoning: -circadian rhythm a bit exceeds 24h, so perfect day would be around 24h and 10 minutes ( http://www.circadiansleepdisorders.org/info/cycle_length.php ) -readjusting year zero, somewhere...