Tidal Definition and 160 Threads

what is tidal gravitational force?

Hello According to general theory is there any explanation of tidal wave in sea due to gravitation of moon. How moon warp space time in such a way so that tidal waves are generated in sea?

Uranus rotates on its side and its poles always point in the same direction... http://www.ifa.hawaii.edu/~barnes/ast110_06/quizzes/disc02_fig01.png ...if it was moved close enough to the sun to become tidally locked, would it necessarily lose all of its current rotation by the time it...

When calculating the energy in a tidal reservoir, when do we use the average height of the water (half the max tidal height) instead of the maximum tidal height in E=mgh?

Homework Statement There is a derivation in the text that I'm having problems replicating. The text gives the formula for tidal potential as: U_{tid}=-GM_{m}m(\frac{1}{d}-\frac{x}{d^{2}_{0}}) Where M_{m} is the mass of the moon, d is the distance from the CM of the moon to the point of...

If the lithosphere were suddenly removed, would the earthtide amplitude of the mantle be larger than the .25m or so now measured for the lithosphere?

Homework Statement Newton's model of the tidal height, using two wells dug to the center of Earth (one from the North pole, one from the equator on the side of Earth facing away from the Moon), used the fact that the pressure at the bottom of the two wells should be the same. Assume water is...

I'm a bit confused about this and would like for someone to help me get this straight. I read in wikipedia that a manifold with more than three dimensions, like spacetime, is conformally flat if its Weyl tensor vanishes. I think all FRW metrics are conformally flat, so I guess our universe is...

Assume we have a non rigid ball. When this ball is radially free falling in a Schwarzschild metric the height increases while the width decreases due to tidal effects. How do we calculate the ruler width and height in terms of R and m? When we have two of those balls radially free falling...

Are all the planets moving away from the Sun? If so, how much?

This is something that I have wondered about for a while now which is related to how tidal power stations work and the law of conservation of energy. Scenario: As far as I am aware the tidal variations all around the world are primarily caused by the gravitational force of the moon on the...

Recently while searching through some old threads in this section of the forums, I came across a few statements that do not seem to me to be entirely self-consistent. I was wondering if someone could tell me which - if any - of these declarations is not correct: -- in a uniformly...

Hi everyone, its been a while since i posted on here but i thought i could do with all your help once again lol. Im in my final year of my degree now and half way through my final year project which is basically to analyse a tidal generator patent show the basic principles with a practical...

Spaghettification outside of a BH rips apart objects in vertical direction, but compresses them in horizontal. Inside the BH, tidal forces rips objects apart in ALL directions - at least I was thinking so. But recently I read: http://arxiv1.library.cornell.edu/abs/0903.4717 The edge of...

I teach marine biology and have been presenting the traditional model of the equilibrium tidal theory (2 humps on rotating earth) as still presented in most basic texts, but have not been able to find the theory or presumed explanation for the apparent generally increasing amplitude in tidal...

Homework Statement At the time of a full moon, the tides repeat with a period of about 12 hours, and the depth of water in a certain channel varies between 2 meters and 6 meters in a way that can be modeled by an equation of the form D(t) = A + Bsin(ct + d), where A is the average depth and...

Can someone briefly describe what is meant by tidal forces?

Homework Statement A tidal power plant generates 10 MW of electricity during a period of 12.5h. Assume that the water is collected behind a dam 6.0m high and is allowed to pass through a turbine twice to generate electricity, once as the tide comes in and once as the tide goes out. What mass...

Mercury is very close to the sun and I think it has been tidal locked, but for its eccentric orbit it can not be faced one half to the sun. Am I right? If it is not locked, what is the scenario that Mercury will have in the future?

Calculating wind load is wind speed squared x .00431 x area in sq. ft. A 5 mph wind with a vertical 100 sq. ft. wing is 10.77 lbs. The mass of salt water is around 854 times greater than the mass of air. Can you use the wind formula and multiply by 854? Does the weight of water at different...

Calculating wind load is windspeed x itself x.00431 x sq. ft. of area. A 100 sq.ft vertical wing in a five mph wind is 10.77 lbs. The mass of salt water is around 854 times that of air. Can you use the wind formula and multiply by 854? Also, does this change with the weight of water at different...

Please confirm, I am not sure. Outside the horizon, object is torn apart in vertical direction but is squezzed in a horizontal. Inside the horizon, object is still torn apart in a 'vertical' direction, and in in the horizontal direction too

After walking along the Thames every day on the way to work, I noticed that the water lever difference is between low and high tide is about 7-8m. Thoughts soon turned to how to harness this for power generation. The idea I had is to have a large weight buoyed so that it would rise with the...

I was slightly exasperated with this http://www.sciencemag.org/cgi/content/abstract/289/5486/1897 report: "It is difficult to explain this predominant cycle in terms of orbital eccentricity because the 100,000-year radiation cycle (arising from eccentricity variations) is much too small in...

It is my understanding that the Equivalence Principle postulates that if I were standing in a closed room, I would not be able to distinguish whether the downward force that I felt was caused by (1) the presence of a massive body such as the Earth exerting a downward gravitational force or (2)...

It is easy to show*, that the Differential (Tidal) Force, produced by the Moon, around the surface (equator) of the Earth, is: \vec{\Lambda F} \approx \frac{G \, M_{moon} \, \delta m \, R_{earth}}{D^{3}} \times \left( 2 cos(\theta) \vec{x} - sin(\theta) \vec{y} \right) The radial component of...

Tidal force in the sci-fi book "The Integral Trees" Hi I'm doing an eksamen exercise for tomorrow about the science fiction book "The Inetgral Trees" by Larry Niven and tidal forces. One of the quiestions are if it is realistic with a tidal force at 1/5g (little italic g - g-force, not gram)...

hi all, i kind of have a black hole regarding my understanding of the consistensy of tidal forces and geodesic deviation analysis. one can determine some coefficients of the riemman tensor from the tidal forces equations, by getting to a form that is like the form of the geodesic deviation...

Hello everyone! Real quick question here, I've been trying to figure this out on my own all day to no avail. Sorry if it is a dumb question... "Can an object locked in orbit, rotate on an axis if the axis is horizontal?" If for example a planet's north pole was locked in orbit to a...

Hi, Given a large number of test particles N, it should be possible to determine the Riemann curvature tensor by tracking their motion as they undergo geodesic deviation. Is there a minimum number N that will achieve this in any situation, or does it vary from problem to problem? How...

Will ever Uranus be tidal-locked by the Sun?

The team of Francis, Barnes, James & Lewis have published several very helpful papers in recent years about the expansion of space (with their names in various orders.) I suggested in a recent thread about their Radar Ranging article that they are trending away from explaining particle...

Homework Statement i was reading this book for school called investigating change and i was really lost on question 4: tides of an area and their times are as follows: high tide: low tide 1.64m 12:08am 0.4m 6:03 am 2.32m 12:46 PM...

According to this article, we'll be gobbled up by the Sun in the (approximately) imminent future, since the mutual bulging of the Sun and Earth from gravitational attraction will in effect slow Earth's motion around the Sun, causing us to die horribly as we spiral inwards. That's it, folks, the...

If a black hole will always rip you apart through tidal effects as you approach it, what are the limits on what can be ripped apart? Will it rip apart atoms, protons, quarks? What do the tidal forces do to light? Does it "rip" light apart?

theres a problem in wheeler's spacetime physics (exercise 2-9) which goes like this : you are in a horizontal railway coach launched upwards from the surface of the earth. there are two ball bearing at opposite ends of the coach. can you distinguish whether the coach is rising or falling by...

I was recently listening to a favorite podcast of mine (AstronomyCast) and they went over the tidal effects the moon's gravity has on the Earth. I just happened to be thinking about the tidal effects after that and was wondering if the moon's gravity effects things in orbit of Earth. More...

I know the following statement to be true, being proven both mathematically, and verified by astronomical observations. What I need help understanding is HOW. . . "The law of Conservation of Angular Momentum requires that the slowing down of the rotation of the Earth around its axis caused...

I need to determine an equation that models tidal patterns. High tide is at 12:00am Low Tide 6:10pm High tide returns at 12:24pm High tide is 5.4m and low tide is .1m Therefore the amplitude is (5.4-0.1)/2 = 2.65 The mean value is 2.65+0.1=2.75 Therefore y=2.65cos(Bx+c)+2.75 Im yet...

I'd like to understand how to calculate the components of Newtonian tidal accelaration tensor in polar coordinates. Is any available Internet source which clearly explains the technique with details? Reading James B. Hartle "Gravity" textbook I stumbled on the following Example from...

Hi, I'm not sure if I'm at the right place to write this message, so please excuse me if I'm not. I have read a bit about tidal forces, but I still don’t understand what they are, how they act on different body masses, etc. So, I thought I could find answers here. I would greatly appreciate it...

Over in the Relativity forum, in the thread "Metrics and Forces", I have been brought (in fact dragged kicking and screaming, by Pervect) to the following view: In the FRW universe with matter, as gravity slows expansion, compressive tidal stresses develop in any entity that is bound by...

imagine a sun and a planet, both rigid and perfectly spherical. the distance between the center of mass of these two bodies is much greater than the radius of both bodies. considering Newton's inverse square law of gravity: now, due to the non-uniform nature of this gravity, different parts...

I´ve been trying to solve this problem but I have been unable. I was able to solve part (a) but I can´t do part (b) I´d appreciate a lot if someone helped me. the problem is the following: Tidal power plants use "tidal energy" to produce electrical energy. To construct a tidal power plant...

How is spacetime curved if the present gravity field is completely uniform and there are no tidal forces. Clocks at a same height would tick the same, at different heights (to the gravity source) would tick differently. But what about space? How is space curved in the absence of tidal forces...

the questions is that: An astronaut inside a spacecraft , which protects her from harmful radiation, is orbiting a black hole at a distance of 120 km from its center. The black hole is 5 times the mass of the sun and has a Schwarzschild radius of 15 km. The astronaut is positioned inside the...

How does one compute the tidal locking radius of say a planet on a putative moon its area? Is there a formula? rieman zeta

I am new and would like some help. I have two questions for a shout out. 1) I need some info to help detirmine the Habitable Zone of a paticular star. I think that JF Kasting propsed some kind of equation but I can't find anymore info on it. I don't really need the equation per say just data...

Hey people, Im doing some analysis of some N-body simulation data. I'm trying to calculate the tidal forces exerted on the smaller groups of particles by the other mass. I have a model for the distribution of matter causing the tidal field so I can analytically calculate the gravitational...

I know that when a spherical shell( of negligible mass) is attracted towards a massive body it distorts into an ellipse; keeping its volume const.I have also heard it said that this volume preserving property belongs to that of the inverse square law of gravity.But how do i prove it mathematically?