Questions tagged [precession]
The precession tag has no usage guidance.
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Does General Relativity predict Mercury's orbital precession without other planets?
From Newtonian mechanics, the precession of Mercury can be calculated by taking into account the gravitational pull of other planets. From that, I assume that in the absence of external planets, ...
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Does retarded Newtonian gravity predict apsidal precession and gravitational radiation?
This is a question that have troubled me for a while, beginning with the historical fact that the apsidal precession of Mercury as noted by Urbain Le Verrier was one of the motivating issues behind ...
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How to understand gyroscopes by using vectors?
I’ve seen plenty of videos explaining how gyroscopes work, but almost non of them why they are constrained to work in such way. From seeing only angular momentum vectors, how could one predict ...
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Larmor precession - analogy with gyroscopic precession
Almost everywhere in scientific literature, Larmor precession is introduced via an analogy with a spinning top.
I understand that in a quantum framework, precession can be explained considering the ...
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What happens if we prevent gyroscope to precess?
If we apply some torque to spinning wheel in a vacuumed space in body frame y axis, wheel try to precess due to gyroscopic effect but it will be prevented by obstacles as seen from picture,
what will ...
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Can I make a tire swing with no initial angular momentum spin while swinging?
Is it possible to make a tire swing with no initial angular momentum spin while swinging?
One way to make it spin while not swinging is to rotate an arm in succession around the three axes; this will ...
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Is this an example of precession, or is its motion more complicated?
Let's say there is a solid cylinder floating in space and rotating about its axis of symmetry at rate $\omega$. At time t = 0 a force constant in magnitude is applied to the bottom of the cylinder. ...
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Experimental liimits on torque free precession of spin?
Inspired by this question, I'd like to know what experimental limits there are on the torque-free precession of particle spin. This is a classical phenomenon, not part of quantum theory, but only ...
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How to calculate the rotation speed of spinning top, which will be enough that it is not falling down or stays within certain angle to vertical axis [duplicate]
I found many articles with the calculation of the precession rotation speed of the spinning top like this or this. They give this equation for Precession rotation speed $\Omega$:
$$\Omega=\frac{mgr}{I\...
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Physical pendulum: axis of rotation
Why is the angular momentum always considered to be parallel to the angular velocity in physical pendulum problems, as if the axis of rotation were a principal axis always? I don't see the ...
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When looking at Gyroscopes, does precession only occur if a force is applied perpendicular to the axis of rotation? or can it be a parallel force?
I am trying to simplify gyroscopic precession for PPL Helicopter students and in the process confused myself. Many texts define it as processing a force 90 degrees when the force is applied 'parallel ...
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GR correction to perihelion precession comparing with newtonian orbit
My professor did the following derivation of the formula for the perihelion precession $\delta \phi = \frac{6\pi G M}{a(1-e^2)}$, but I am missing a factor of 2. I would appreciate if someone can help ...
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Thomas precession and the whether or not the two frame can be directly boosted in special relativity
In the common treatment of the Thomas precession, there are three frames:
the rest frame of the nucleus
the instantaneous frame associated with the electron at the time t, having a velocity of v in ...
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Free Body Diagram of Precessing Top
Consider a heavy, symmetric top spinning on a table, initially inclined at some angle from the vertical. Assuming this angle is fixed, it follows that the weight $\textbf W$ and normal force $\textbf ...
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Which direction will the gymnastics tilt twist turn me? Figuring out rotation direction in torque-free precession
I'm trying to understand the physics of tilt twisting in gymnastics / trampolining, and I've run into a conundrum where theory doesn't seem to agree with practice, so I'm looking for where my mistake ...
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Does the accelerated expansion of the universe have any effects in the orbital precession of galaxies? And in their eccentricity?
I found several papers (https://iopscience.iop.org/article/10.3847/2041-8213/ace90b; https://link.springer.com/article/10.1134/S1063772920100054; https://arxiv.org/abs/gr-qc/0301057; https://arxiv.org/...
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Two speeds of precession without nutation
I understand mathematically that when you look for solutions to the equations of motion of a spinning symmetric top with a constant inclination angle $\theta$, you get a quadratic equation with two ...
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Direct calculation of the geodetic precession for the comoving observer
In the text book "Gravity" written by Hartle (p.302), the precession angle per orbit of a gyroscope, initially lied in the equatorial plane and in the radial directon) moving in a circular ...
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Choice of axis in analysis of gyroscopic precession
In many demonstrations of analysis of gyroscopic precession, the analysis goes on by choosing two axes, one about which angular momentum is calculated, another about which torque of gravity is ...
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Why does the period of precession of a gyroscope have to be way larger than it's spin period so that it's motion can be modelled?
Mathematically, torque induced gyroscopic precession may be modelled with the following equation:
$$
{\displaystyle T_{\mathrm {p} }={\frac {4\pi ^{2}I_{\mathrm {s} }}{\ mgrT_{\mathrm {s} }}}={\frac {...
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Energy conservation in Landau-Lifshitz Equation [closed]
considering the Landau-Lifshitz equation for magnetisation dynamics,
$\frac{\vec{M}}{dt}=-\gamma (\vec{M} \times \vec{H})$
In this article (https://arxiv.org/abs/1101.1005), the author argues that $\...
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What effects do we have to take in account to calculate the total precession of a gyroscope orbiting close to a black hole?
I've read about the Lense–Thirring precession which applies to bodies orbiting rotating masses. But there is also the geodetic effect (de Sitter precession), which is caused by the curvature of ...
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Spinning Wheel subjected to Gravitational Force
have a question about the dynamics of a suspended horizontally rotating wheel subjected to gravitational force like in following picture I took from here:
At the beginning the wheel has an angular ...
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Is the Laplace-Runge-Lenz vector applicable for test particle motion around black holes?
In classical mechanics , the Laplace-Runge-Lenz (LRL) vector is a characteristic feature of the Kepler problem. This enables a very simple discussion of the properties of the orbit for the problem. It ...
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Why do bullets precess in the opposite direction from gyroscope diagrams?
Bullet spin causes a bullet to become a gyroscope. Specifically, bullets have their center of pressure in front of their center of mass. Therefore, when pressed, gyroscopic forces cause a bullet to ...
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Is Energy conserved in a spinning top?
When we spin a top (give it kinetic energy $K_0$) and place it on a table, it starts precessing around the vertical axis.
Is the total energy of the spinning and precessing top equal to the initial ...
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Weird rotational motion of a heavy thick disc
I and my friend noticed a strange behaviour of a rotating disc (or a cylinder) and we don't know how is that happening.
This is the video.
Actually what is happening in the video is that the disc ...
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How to calculate the distance of Mercury's perihelion shift in meters? [closed]
Since the shift in mercury's perihelion shift is 2.88E-5 degrees and mercury's altitude above the Sun at its perihelion is 46001200000 meters, can I use the formula for an isosceles triangle to ...
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How to obtain Mercury Precession equation $\frac{d^2u}{d\theta^2}+u=a$?
Let $r=R(t)$ and $\theta=\Theta(t)$ describe the orbit of the planet. Define $$u(\theta)\equiv\frac{\bar r}{R[\Theta^{-1}(\theta)]}$$ where $\bar r=5.83\times 10^{12}$ cm be the mean value of the ...
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Response of a loop of current vs. a rigidly rotating charged ring to a magnetic field
In a uniform magnetic field, a loop of current on a wire will feel a torque that makes the magnetic moment of the loop align with the field direction. But for a rigidly rotating ring of charge, its ...
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How can I conceptually interpret spin precession?
In Sakurai section 2.1, he works through an example of spin precession where we come to the conclusion that, when working in the z-basis and applying a magnetic field in the z-direction, the spin ...
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Pencil doesn't act as a spinning top
If one spins a spinning top, it'll stay up for a while before falling down. However, if one spins a pencil, it falls down immediately, just like if you didn't spin it at all. My question is why there ...
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Gyroscopic bicycle wheel - forces on the wheel only
This is a standard problem in university physics, which I studied at university in depth. With higher concepts like angular momentum, it is fairly straightforward to explain the motion.
However, one ...
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Can orbiting point masses precess?
In a recent Science News, it mentioned two orbiting black holes (which later combined) were precessing; i.e. their motion did not remain in a stable plane, but rather the plane itself was changing. ...
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Why is precession angular velocity of a gyroscope independent of the angle of its axis?
I'm making gyroscopes in my shop and studying precession. Studied dynamics in 1964 so may have forgotten a thing or two.
Consider a gyroscope or top spinning with its axis at angle $\beta$ with ...
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Is the diameter of earth's north pole similar to the south? (Think axis of rotation+ axis of precession)
Earth is an oblate spheroid, not a sphere, since it's rotation around the axis causes it to bulge along the equator.
Is it teally a symetric oblate spheroid though, or also not even that?
To explain: ...
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NMR without static magnetic field
NMR is usually conducted by first aligning nuclei to a strong, constant magnetic field, so that you can apply RF radiation with a magnetic component directly perpendicular to the constant field. ...
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Geodetic Precession of a Gyroscope in Hartle's GR Book
In 14.3, Hartle deduces the geodetic precession angle per orbit of a gyroscope in Schwarzschild geometry. Immediately after eq.(14.18), the book reasons that the angle deduced is physically measured ...
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Is it right assume the greater the precession of a type of particle in the same magnetic field the slower the particle spin?
Is it right that the greater the Larmor frequency of a particle measured for same magnetic field applied the slower a particle spin is? I read these articles http://hyperphysics.phy-astr.gsu.edu/hbase/...
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How can precession produce a torque in the direction of precession when it has no angular momentum?
Updated question, also includes somewhat of an answer.
To clarify the point about precession having no angular momentum, if the torque that induces precession is suddenly removed, the gyro suddenly ...
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Proton spin precession and alignment to magnetic field in NMR
Precession due to magnetic field occurs when the magnetic moment of a small coil is proportional to its angular momentum ($\vec{m}=g\vec{L}$). This is due to Euler momentum equation, which for such a ...
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Direction of angular velocity vector VS angular momentum vector
I understand that angular velocity and angular momentum velocities don’t need to be parallel to each other. However, I’m confused what these vectors even represent. So I have 3 questions about this:
...
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Confusion about the Spinning Top
Consider the following symmetric spinning top with a fixed point on the horizontal surface.
I have two questions concerning its motion:
let $\underline{\Omega}$ denote the precession angular ...
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Is it possible to change the speed at which a wheel is freely spinning by moving only its axle?
Suppose we have a wheel spinning on a perfectly lubricated axle. Is it possible to change its angular velocity about that axle, by moving only the axle?
Due to the wheel's symmetry about the axle's ...
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Non-swinging Foucault's pendulum
If there is a stationary pendulum, say at the North pole, neglecting torsion, etc. will it seem like spinning around its axis from the reference frame fixed to the Earth's surface. If so, will it ...
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Will the inner gimbal continue to rotate if no friction?
The picture shows a gyroscope with a rotating disk.
Adding a force to the outer gimbal from a certain direction causes the inner gimbal (plus the disk with bearings) to rotate as well. When the force ...
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Resisting Precession of a Gyroscope
its known that if a torque is applied to a spinning gyro, the gyro will pitch. There's a lot physics on the pitch speed, but what is the torque to induce this pitching?
ps. I am building a gyro ...
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Equation to tell if precession will happen?
So I have an seen the equation to calculate precession but it breaks down at when there is not sufficient angular momentum, for example if an object is not spinning we divide by zero and the ...
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"Precession" of a free electron
I'd like to gain as deep of an understanding as possible of the following diagram from Introductory Quantum Mechanics, 4th ed., by Richard Liboff:
I'm not looking for help with solving the easy ...
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Definition of rotation moment in a vertical surface during forced precession of a gyroscope
I have the following assumption:
Moment of gyroscope flywheel created by gravity force:
Rotation moment of natural precession due to gravity forces:
Since the flywheel does not drop:
However, when ...
