Questions tagged [precession]

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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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What will happen when external magnetic filed disappear suddenly in Larmor precession?

Larmor precession is a phenomenon that when we place a magnetic dipole in the external magnetic field, the magnetic dipole will rotate around the direction of the magnetic field. But I am not quite ...
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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 ...
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Puzzle with the precession of the neutron spin?

More perplexing news about the neutron spin in this recent Nature Physics publication: arxiv.org/abs/2103.03333 The authors collaboration (more than 100 authors) report a newly experimentally found ...
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Antigravity force in powered precession gyroscope [closed]

I have an idea that a powered for rotation gyroscope with fixed precession can serve as antigravity engine. I also wonder of someone tried an experiment to prove that it does not work. The following ...
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Kinematics of a rolling disk on a static disk (variation of the Euler disk)

I'm puzzled by the following problem. Consider a simple tilted disk $\mathcal{D}$ of radius 1 (in any unit) rolling without sliding on top of a static horizontal disk $\mathcal{S}$. The normal $\...
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Is Bertrand's Theorem Consistent with GR?

Bertrand's Theorem - Please observe the gif of orbits with different exponents in the denominator. (I couldn't get the image upload feature to work for this) Note, the orbit with a 1.9 exponent ...
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What explains the descrepancy between Asaph Hall's equation for Mercury's precession and GR?

In regard to What is the weight equation through general relativity?, the answer is: $$F=ma=\frac{GMm}{r^2}\frac{1}{\sqrt{1-\frac{2GM}{c^2r}}}.$$ This source provides a different equation: $$f \approx ...
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A unusual derivation of thomas precession

I'm very confused about a strange derivation of the thomas precession. I hope someone can clarify me. We define 3 different frame : the laboratory frame, the rest frame of the particle and an inertial ...
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Does motorcycle counter-steering work by precessional motion?

When a motorcycle is going over a particular speed ($\approx 20$ m/h or 30 km/h) you learn in motorcycle class the best way to steer is using the so-called "counter steering"; I can't find ...
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Newtonian contribution to perihelion precession of Mercury

We have seen that the orbits of the planets around the sun can be found, to a good approximation, by only considering a two-body system (a planet and the sun) interacting through a central force. ...
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Gyroscopes and Conservation of Angular Momentum follow-up

I'd like to follow up on a question I asked two years ago under the same title (Sept. 22, 2019). I am trying to understand just exactly how angular momentum around the vertical axis is conserved ...
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Does nutation require $n \ge 2r$?

I'll start of with my (mis)understanding: We have a planet orbiting around another body. The orbiting planet has infinitely many axes passing through it, but we're interested in two, $A_1$ and $A_2$. $...
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Is it the centripetal force due to precession that prevents a spinning wheel from falling? [duplicate]

An object tied to a rope will lift when swung around (like in a merry-go-round), due to the centripetal force. If a rapidly spinning wheel is hanging from a rope at one side of the axis, it won't fall ...
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Why $\vec{\mathfrak{m}}$ and $\vec{J}$ are collinear when considering precession in magnetic field?

Recently I have read about magentization of paramagnetic materials and precession of atoms in magnetic field. So, I found the following formula: $\vec{\mathfrak{m}} = \Gamma \vec{J}$, where $\vec{\...
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Which way do Feynman's plates precess?

I assume people are familiar with the story of Feynman watching students toss dinner plates in the air in the cafeteria, and how working out the relation between the spin rate and the precession rate ...
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Is electron diamagnetic resonance (invoking Larmor precession) possible?

Diamagnetism is observed in materials where electrons are paired. These paired electrons have opposite magnetic dipole moments. Therefore, the total magnetic torque on the pair's magnetic dipole ...
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Why does a rotating mass generate a torque on an attached object?

In this video, we see a little toy vehicle with two wheels that is unstable by itself. However, when an attached gyroscope is running (a rotating mass) it stabilizes itself. When the mass starts to ...
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Why does a precessing wheel remain horizontal, instead of flipping?

Suppose I have a wheel with an axle, such that one side of the axle is tied to a rope. I'm initially holding wheel in such a way, that the radius vectors of the wheel are perpendicular to a board. I ...
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How much differs the Mercury speed at perihel from its theoretical speed with no frame dragging involved?

How much differs the Mercury speed at perihel from its theoretical speed with no frame dragging involved? Can a formula of frame dragging velocity be calculated regarding the distance of a point of ...
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1 vote
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What are centripetal forces for flywheel precession movement?

What are centripetal forces for this flywheel? I suppose for rotation around "inner" axis centripetal force is due to attractive forces between particles inside flywheel. However what about ...
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Does precession affect loss of angular velocity in collisions?

I'm a higher schooler trying to do a project on how moment of inertia affects loss of angular velocity in spinning top collisions. Right now, I'm trying to find factors that might affect my results ...
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What is the Precession direction of positron?

In Larmor precession; The spin angular momentum of an electron precesses counter-clockwise about the direction of the magnetic field(An electron has a negative charge, so the direction of its magnetic ...
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Intuitive derivation for the precession rate of a spinning wheel

The derivation of the precession rate of a wheel hanging from a rope, as shown below usually involves taking the total torque acting on the system and equating it to the change in angular momentum. ...
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Derivation of precession rate of a wheel gyroscope [closed]

I searched on the web and all I could find is the precession rate of a spinning top. But what I want is the derivation of the precession rate of a wheel hanging from a rope, as shown below: which is ...
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Combining Newtonian Gravity and length contraction from SRT?

The value of $\gamma$ that I will use is $$\gamma=\sqrt{1-\frac{v^2}{c^2}}$$ And length contraction is $$L_0=\frac{L}{\gamma}$$ Where all variables have usual meaning. Let the gravitational pull on ...
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3 votes
4 answers
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How do I calculate Earth's axial precession in an idealized Sun-Earth system?

I am experimenting with an idealized two-body system based on the Sun-Earth system. I want to calculate how much Earth's axis precesses and nutates given the simplified setup. In my system, the orbit ...
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Confusion on conservation of angular momentum

Can someone explain how angular momentum is conserved while at the same time precession in freely rotating objects happens? It seems contradictory.
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Do paired electrons precess under a magnetic field? Is there a way to know?

The spins of paired electrons are opposite of one another, but so are their magnetic moments. Thus, an externally applied magnetic field will exert opposite torques to opposite spins. Doesn't that ...
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Gyroscope precession: angular momentum and torque

I recently bought a Gyroscope toy online and was keen to find out the Physics behind this fun little "gravity-defying" toy. I did some online research and found a force diagram of a ...
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Why does the gyroscope oscillate a little when it just starts to precess?

I was reading up on why before starting the precession the gyroscope "goes down a little", (Link at the bottom). In this paper, while looking at the graphs I observed that before reaching ...
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State of the art on relativistic perihelia precession in Solar System (other than Mercury)

The correct prediction of anomalous precession rate of Mercury perihelion is a classical test of General Relativity and one of its' big triumphs. How about other planets in the Solar System? ...
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Is precession a property of asymetric objects only? How to explain Larmor precession?

Is precession a property of asymmetric objects only? How to explain Larmor precession? A proton could be asymmetric due to its compositeness but what about electrons?
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What is the relative importance of the Coriolis term to the precession term in frame dragging by rotating Kerr black holes?

The Wikipedia entry for Thirring precession describes the Coriolis term as separate from the precession term. Is it fair to say that when looking at the dynamics of a rotating black hole, the ...
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Does Newton's Theory with Retarded potentials give rise to the motion of perihelion of Planets

If we take into account the retarded potentials and the motion of the Sun(due to the planet), does Newton's Gravitational theory give rise to the motion of Perihelion of planets (qualitatively, not ...
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2 votes
3 answers
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Is it possible to estimate the 23.5° tilt of Earth's axis?

Using the value of the precession of Earth's axis in 25,800 years and the value of Earth's radius, mass, moment of inertia etc., would it be possible to calculate/estimate that Earth's axis must be ...
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is room temperature quantum (qubit) nuclear magnetic resonance possible?

I know it is possible to do room temperature NMR. Not just that but one can also use the earth's magnetic field for the nuclei to precess about. If done this way, one gets precession at about the KHz ...
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Precession of a flywheel on earth

I’m currently working on a mechanical problem and I’ve got a couple of questions. First, let me describe the problem. We’ve got a flywheel somewhere on the surface of the earth spinning merrily. It is ...
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2 votes
1 answer
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Difference in the precession regarding the gravitational gradient

Let say a less massive star acts on a planet causing it to precess.Does a more massive star cause less precession of this planet if in both cases the gravitational force applied to the planet center ...
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1 vote
1 answer
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How do frame dragging affects a photon for outside observer?

I remember an analogy that explained this phenomenon using magnetic field, a charged particle will experience a force next to another spinning charged particle or something like that. But I don't want ...
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Why stars don't precess?

Assuming that rotation of stars, galaxies etc is determined basically randomly, the question is: why do all space objects rotate so 'neatly', with little or no precession? And what precession there is ...
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Inertial precession of a rigid body

Is inertial precession of a rigid body possible? In other words, can [axis of rotation of a rigid body] rotate itself inertially and perpetually around the center of mass? Assuming no torque, no ...
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2 votes
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Is there still an anomalous precession in Mercury's orbit that GR doesn't predict?

I was reading through the Wiki pages on tests of relativity and I was curious about this section. Am I interpreting it correctly? Is there still about $1.21''/\text{ cy}$ of precession (Total ...
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Precession - why decompose to angular momentum component?

I always see it is conventional (in Landau-Lifshitz for example) to decompose the angular velocity vector to 2 components: axis of symmetry and angular momentum vector, and then define the angular ...
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Centripetal force in a gyroscope

I realize there is another question on the centripetal force involved in a gyroscope's motion, but I found the answer to not be very complete. With respect to a gyroscope attached to a vertical spring ...
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Precessional motion of a spinning top

In Feynman's book, when he talks about the motion of a rapidly spinning top, he mentions: "When we apply a Torque to a rapidly spinning top, the direction of the precessional motion is in the ...
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Precession of a closed orbit under a central force other than the inverse square force

Consider the motion of a closed orbit in a central force field ${\bf F}({\bf r})$ other than the inverse square force i.e., $${\bf F}({\bf r})\neq -\frac{k}{r^2}\hat{\bf r}.$$ However, since ${\bf F}({...
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Conceptual Question About Gyroscopic Precession of body about Two Axes

I've been trying to glean some insight into the motion of a body that is rotating about an axis through the COM of said body whilst traveling in a orbital-like path about a perpendicular axis outside ...
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Minimum gyro speed to yield force precession

Does anyone know what the minimum speed of a gyro to make it so a force at 0deg will yield a movement at 90deg? or even better, what the angle is wrt speed? see http://www.copters.com/aero/gyro.html ...
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