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The rotation axis of the Earth describes, over a period of 25, 700 years, a small circle ( blue ) among the stars, centered on the ecliptic north pole ( the blue E ) and with an angular radius of about 23. 4 °, an angle known as the obliquity of the ecliptic.
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rotation and axis
If the platform is not properly headed, the X-gyro input axis will see a component of the earth's rotation.
When the platform is level, **ye is a rotation about the Z axis of the platform Af.
The increasing eastward momentum imparted by the winds causes water parcels to drift outwards from the axis of the Earth's rotation ( in other words, northward ) as a result of the Coriolis force.
In order to maintain this alignment, Hindu astrology uses an adjustment, called ayanamsa, to take into account the gradual precession of the vernal equinox ( the gradual shift in the orientation of the Earth's axis of rotation ).
A third twofold axis of rotation passes through the C = C = C bonds, and there is a mirror plane passing through both CH < sub > 2 </ sub > planes.
For a rigid body rotating around an axis of symmetry ( e. g. the blades of a ceiling fan ), the angular momentum can be expressed as the product of the body's moment of inertia, I, ( i. e. a measure of an object's resistance to changes in its rotation rate ) and its angular velocity ω:
For the case of an object that is small compared with the radial distance to its axis of rotation, such as a tin can swinging from a long string or a planet orbiting in a circle around the Sun, the angular momentum can be expressed as its linear momentum,, crossed by its position from the origin, r. Thus, the angular momentum L of a particle with respect to some point of origin is
For many applications where one is only concerned about rotation around one axis, it is sufficient to discard the pseudovector nature of angular momentum, and treat it like a scalar where it is positive when it corresponds to a counter-clockwise rotation, and negative clockwise.
Sometime this may not be possible, in these cases the angular momentum component along the axis of rotation is the product of angular velocity and moment of inertia about the given axis of rotation.
The conservation of angular momentum explains the angular acceleration of an ice skater as she brings her arms and legs close to the vertical axis of rotation.
In the Robinson anemometer the axis of rotation is vertical, but with this subdivision the axis of rotation must be parallel to the direction of the wind and therefore horizontal.
In addition, a rotation axis at an angle to the magnetic axis may be spinning different bands of magnetically-sorted elements into the line of sight between Alioth and the Earth.
However, if neither the central object nor the surrounding ring were absolutely rigid then the parts of one or both of them would tend to fly out from the axis of rotation.
The height of the water h = h ( r ) is a function of the radial distance r from the axis of rotation Ω, and the aim is to determine this function.
where r is the radius from the axis of rotation.
The principle of operation of the centrifuge also can be simply understood in terms of this expression for the potential energy, which shows that it is favorable energetically when the volume far from the axis of rotation is occupied by the heavier substance.
The direction of the curl is the axis of rotation, as determined by the right-hand rule, and the magnitude of the curl is the magnitude of rotation.
rotation and Earth
Time coordinates on the TAI scales are conventionally specified using traditional means of specifying days, carried over from non-uniform time standards based on the rotation of the Earth.
This in turn results in the slowing down of the rotation rate of Earth ( at about 42 nsec / day ), and in gradual increase of the radius of Moon's orbit ( at ~ 4. 5 cm / year rate ).
In what he called " first philosophy " or metaphysics, Aristotle did intend a theological correspondence between the prime mover and deity ( presumably Zeus ); functionally, however, he provided an explanation for the apparent motion of the " fixed stars " ( now understood as the daily rotation of the Earth ).
That the Earth is itself an oblate spheroid, bulging at the equator where the radial distance and hence the centrifugal force is larger, is taken as one of the evidences for its absolute rotation.
The Coriolis effect is caused by the rotation of the Earth and the inertia of the mass experiencing the effect.
Because the Earth completes only one rotation per day, the Coriolis force is quite small, and its effects generally become noticeable only for motions occurring over large distances and long periods of time, such as large-scale movement of air in the atmosphere or water in the ocean.
However, there are other forces changing the rotation rate of the Earth.
This " post-glacial rebound " brings mass closer to the rotation axis of the Earth, which makes the Earth spin faster ( law of conservation of angular momentum ): the rate derived from models is about − 0. 6 ms / day / cy.
So the net acceleration ( actually a deceleration ) of the rotation of the Earth, or the change in the length of the mean solar day ( LOD ), is + 1. 7 ms / day / cy.
Ephemeris time ( ET ), adopted as standard in 1952, was originally designed as an approach to a uniform time scale, to be freed from the effects of irregularity in the rotation of the earth, " for the convenience of astronomers and other scientists ", for example for use in ephemerides of the Sun ( as observed from the Earth ), the Moon, and the planets.
But in the later nineteenth and early twentieth centuries, with increasing precision of astronomical measurements, it began to be suspected, and was eventually established, that the rotation of the Earth ( i. e. the length of the day ) showed irregularities on short time scales, and was slowing down on longer time scales.
Thus the aim developed, to provide a new time scale for astronomical and scientific purposes, to avoid the unpredictable irregularities of the mean solar time scale, and to replace for these purposes Universal Time ( UT ) and any other time scale based on the rotation of the Earth around its axis, such as sidereal time.
The shape of the Earth is to a large extent the result of its rotation, which causes its equatorial bulge, and the competition of geological processes such as the collision of plates and of volcanism, resisted by the Earth's gravity field.
All these techniques also serve to monitor Earth rotation irregularities as well as plate tectonic motions.
Twenty-some superconducting gravimeters are used worldwide for studying Earth tides, rotation, interior, and ocean and atmospheric loading, as well as for verifying the Newtonian constant of gravitation.
The daily rotation of the Earth is somewhat irregular ( see ΔT ) and is slowing down slightly ; atomic clocks constitute a much more stable timebase.
There are no oceans or landmasses to cause local heating, and the rotation speed is much faster than it is on Earth.
The centrifugal force from the Earth's rotation would pull a person ( on the inner surface ) outwards if the person was traveling at the same velocity as the Earth's interior and was in contact with the ground on the interior, but even the maximum centrifugal force at the equator is only 1 / 300 of ordinary Earth gravity.
For example, the centrifugal acceleration of the Earth because of its rotation about the Sun is about thirty million times greater than that of the Sun about the galactic center.
Its major part resembles the field of a bar magnet (" dipole field ") inclined by about 10 ° to the rotation axis of Earth, but more complex parts (" higher harmonics ") also exist, as first shown by Carl Friedrich Gauss.
Because the discrepancy is not fully explained, uncertainty of our prediction of UT ( rotation angle of the Earth ) may be as large as the difference between these values: 11 s / cy < sup > 2 </ sup >.
The Earth's axis of rotation – and hence the position of the North Pole – was commonly believed to be fixed ( relative to the surface of the Earth ) until, in the 18th century, the mathematician Leonhard Euler predicted that the axis might " wobble " slightly.
There is another disturbance of the Earth's rotation called polar motion that can be estimated for only a few months into the future because it is influenced by rapidly and unpredictably varying things such as ocean currents, wind systems, and motions in the liquid nickel-iron outer core of the Earth.
rotation and describes
In vector calculus, the curl is a vector operator that describes the infinitesimal rotation of a 3-dimensional vector field.
The Lorentz transformation describes only the transformations in which the spacetime event at the origin is left fixed, so they can be considered as a hyperbolic rotation of Minkowski space.
The angular velocity vector also describes the direction of the axis of rotation.
In the limit will be in the direction N and the curvature describes the speed of rotation of the frame.
Small-scale rectangular raster image maps can have an associated world file for GIS map software which describes the location, scale and rotation of the map.
The angular velocity describes the speed of rotation and the orientation of the instantaneous axis about which the rotation occurs.
The magnitude is the angular speed, and the direction describes the axis of rotation.
Born and Oppenheimer wrote the paper: This paper describes the separation of electronic motion, nuclear vibrations, and molecular rotation.
The translation vector common to all points of the object describes a particular type of displacement of the object, usually called a linear displacement to distinguish it from displacements involving rotation, called angular displacements.
The Hoop Conjecture describes an imploding star turning into a black hole when the critical circumference of the designed hoop can be placed around it and set into rotation.
This can be explained intuitively by the fact that a quaternion describes a rotation in one single move (" please turn radians around the axis driven by vector "), while the Euler angles are made of three successive rotations.
More specifically it describes a low-pressure area whose center of rotation is just off the East Coast and whose leading winds in the left forward quadrant rotate onto land from the northeast.
In geometry and linear algebra, a rotation is a transformation in a plane or in space that describes the motion of a rigid body around a fixed point.
Angular velocity is a vector quantity that describes the angular speed at which the orientation of the rigid body is changing and the instantaneous axis about which it is rotating ( the existence of this instantaneous axis is guaranteed by the Euler's rotation theorem ).
Two of these angles describe the orientation of the molecular axis in space as for a linear molecule, and the third describes the rotation of the molecule about this axis.
In the limit will be in the direction N and the curvature describes the speed of rotation of the frame.
Most commonly, it describes those special features of the Dynkin diagram D < sub > 4 </ sub > and the associated Lie group Spin ( 8 ), the double cover of 8-dimensional rotation group SO ( 8 ), arising because the group has an outer automorphism of order three.
describes an isoclinic rotation, a rotation through equal angles ( 180 °) through two orthogonal planes.
The rotation axis of the Earth describes over a period of about 25800 years a small circle ( blue ) among the stars, centred around the ecliptic coordinates | ecliptic northpole ( blue E ) and with an angular radius of about 23. 4 °: the angle known as the obliquity of the ecliptic.
In the case of rotation around a fixed axis of a rigid body that is not negligibly small compared to the radius of the path, each particle of the body describes a uniform circular motion with the same angular velocity, but with velocity and acceleration varying with the position with respect to the axis.
The surface and the embedding may be described combinatorially using a rotation system, a cyclic order of the edges surrounding each vertex of the graph that describes the order in which the edges would be crossed by a path that travels clockwise on the surface in a small loop around the vertex.
Back spinning describes the act of manually manipulating a vinyl record ( currently playing on a turntable ), using enough force to cause the record to spin backward ( despite the rotation of the platter beneath it ).
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