 An animation showing the rotation of the Earth.
 On a prograde planet like the Earth, the sidereal day is shorter than the solar day. At time 1, the Sun and a certain distant star are both overhead. At time 2, the planet has rotated 360° and the distant star is overhead again but the Sun is not (1→2 = one sidereal day). It is not until a little later, at time 3, that the Sun is overhead again (1→3 = one solar day). The Earth's rotation is the rotation of the solid earth around its own axis, which is called Earth's axis or rotation axis. The earth rotates towards the east, which can be observed by orientation with a magnetic compass at sunrise. As viewed from the star Polaris, the Earth turns counter-clockwise. Image File history File links No higher resolution available. ...
Image File history File links No higher resolution available. ...
Image File history File links Sidereal day compared to solar day for a prograde planet like the Earth. ...
Image File history File links Sidereal day compared to solar day for a prograde planet like the Earth. ...
This article is about retrograde motion. ...
Solar time is based on the idea that, when the sun reaches its highest point in the sky, it is noon. ...
A sphere rotating around its axis. ...
This article is about Earth as a planet. ...
The Experimental Advanced Superconducting Tokamak (EAST, internally called HT-7U) is a project being undertaken to construct an experimental superconducting tokamak magnetic fusion energy reactor in Hefei, the capital city of Anhui Province, in eastern China. ...
This article is about the navigational instrument. ...
A typical sunrise, in New Zealand A sunrise through clouds over Oakland, California. ...
Polaris (α UMi / α Ursae Minoris / Alpha Ursae Minoris), more commonly known as The North Star or simply North Star, is the brightest star in the constellation Ursa Minor. ...
Rotation period The average rotation period of the Earth is called a "sidereal day". Its value is 23 hours 56 minutes and 4.091 seconds, and describes the rotation with respect to the cosmic background of the stars. In contrast to this, the rotation with respect to the Sun is 24 hours, differing because the Earth revolves around the sun once per year. Per day the difference is: 86,400 s / 365.25 = 236 seconds = 3 m 56 s (as can be seen above). In astronomy, a rotation period is the time an astronomical object takes to complete one revolution around its rotation axis relative to the background stars. ...
On a prograde planet like the Earth, the sidereal day is shorter than the solar day. ...
The hour (symbol: h) is a unit of time. ...
A minute is a unit of time equal to 1/60th of an hour and to 60 seconds. ...
Look up second in Wiktionary, the free dictionary. ...
The term background can have any of the following meanings: Background (computer software) refers to software that is running, but not being displayed. ...
Sol redirects here. ...
This must not be confused with the length of day (abbrev. LOD), which the IERS defines as the difference between the duration of the day (relative to the Sun) and 86,400 SI seconds.[1] The International Earth Rotation Service (IERS) is the body responsible for maintaining global time and reference frame standards, notably through its Earth Orientation Paramater (EOP) and International Celestial Reference System (ICRS) groups. ...
The permanent monitoring of the Earth's rotation requires the use of Very Long Baseline Interferometry coordinated with the Global Positioning System, Satellite laser ranging, and other satellite techniques, this provides the absolute reference for the determination of universal time, precession, and nutation.[2] Very Long Baseline Interferometry (VLBI) is a type of astronomical interferometry used in radio astronomy, in which the data received at each antenna in the array is paired with timing information, usually from a local atomic clock, and then stored for later analysis on magnetic tape or hard disk. ...
GPS redirects here. ...
In satellite laser ranging (SLR) a global network of observation stations measure the round trip time of flight of ultrashort pulses of light to satellites equipped with retroreflectors. ...
For other uses, see Satellite (disambiguation). ...
For referencing in Wikipedia, see Wikipedia:Citing sources. ...
Universal Time (UT) is a timescale based on the rotation of the Earth. ...
Precession of a gyroscope Precession refers to a change in the direction of the axis of a rotating object. ...
Rotation (green), Precession (blue) and Nutation (red) of the Earth Nutation is a slight irregular motion (etymologically a nodding) in the axis of rotation of a largely axially symmetric object, such as a gyroscope or a planet. ...
Over millions of years, the rotation is significantly slowed by gravitational interactions with the Moon: see tidal acceleration. This article is about Earths moon. ...
It has been suggested that Tidal friction be merged into this article or section. ...
Precession The axis of the Earth's rotation tends, like the axis of a gyroscope, to maintain its orientation with respect to inertial space. External forces acting on Earth from the Sun, Moon, and planets cause deviations from the fixed orientation. The large, periodic shift of the Earth's axis is called precession, while the smaller corrections are nutation and polar motion. In physics, the expression inertial space refers to the background reference that is provided by the phenomenon of inertia. ...
Sol redirects here. ...
This article is about Earths moon. ...
The eight planets and three dwarf planets of the Solar System. ...
The precession of Earths axis of rotation with respect to inertial space is also called the precession of the equinoxes. ...
Rotation (green), Precession (blue) and Nutation (red) of the Earth Nutation is a slight irregular motion (etymologically a nodding) in the axis of rotation of a largely axially symmetric object, such as a gyroscope or a planet. ...
This article needs to be wikified. ...
Physical effects The velocity of the rotation of earth has had various effects over time, including earth's circular shape, climate, ocean depth, and tectonic forces.[3] In physics, velocity is defined as the rate of change of displacement or the rate of displacement. ...
This article is about Earth as a planet. ...
The philosophical concept of causality or causation refers to the set of all particular causal or cause-and-effect relations. ...
A circular may be: the adjective form of circle an advertisement which is circulated a Pastoral letter, Encyclic, or Papal bull that is circulated between churches a circular argument is a term for a type of logical fallacy where the very thing that is trying to be proved is assumed...
Animated map exhibiting the worlds oceanic waters. ...
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Origin of rotation It is theorized that Earth formed as part of the birth of the Solar System: what eventually became the solar system initially existed as a large, rotating cloud of dust, rocks, and gas. It was composed of hydrogen and helium produced in the Big Bang, as well as heavier elements ejected by supernovas. Then, as one theory suggests, about 4.6 billion years ago a nearby star was destroyed in a supernova and the explosion sent a shock wave through the solar nebula, causing it to gain angular momentum. As the cloud began to accelerate its rotation, gravity and inertia flattened it into a protoplanetary disk oriented perpendicularly to its axis of rotation. Most of the mass concentrated in the middle and began to heat up, but small perturbations due to collisions and the angular momentum of other large debris created the means by which protoplanets began to form. The infall of material, increase in rotational speed and the crush of gravity created an enormous amount of kinetic heat at the center. Its inability to transfer that energy away through any other process at a rate capable of relieving the build-up resulted in the disk's center heating up. Ultimately, nuclear fusion of hydrogen into helium began, and eventually, after contraction, a T Tauri star, ignited into our early Sun. Meanwhile, as gravity caused matter to condense around the previously perturbed objects outside of the new sun's gravity grasp, dust particles and the rest of the protoplanetary disk began separating into rings. Successively larger fragments collided with one another and became larger objects, ultimately destined to become protoplanets.[4] Image File history File linksMetadata Ra4-protoplanetary-disk. ...
Image File history File linksMetadata Ra4-protoplanetary-disk. ...
A protoplanetary disc (also protoplanetary disk, proplyd) is an accretion disc surrounding a T Tauri star. ...
This article is about the Solar System. ...
Look up dust in Wiktionary, the free dictionary. ...
For other uses, see Rock (disambiguation). ...
For other uses, see Gas (disambiguation). ...
General Name, Symbol, Number hydrogen, H, 1 Chemical series nonmetals Group, Period, Block 1, 1, s Appearance colorless Atomic mass 1. ...
General Name, Symbol, Number helium, He, 2 Chemical series noble gases Group, Period, Block 18, 1, s Appearance colorless Standard atomic weight 4. ...
For other uses, see Big Bang (disambiguation). ...
The periodic table of the chemical elements A chemical element, or element, is a type of atom that is defined by its atomic number; that is, by the number of protons in its nucleus. ...
Multiwavelength X-ray image of the remnant of Keplers Supernova, SN 1604. ...
STAR is an acronym for: Organizations Society of Ticket Agents and Retailers], the self-regulatory body for the entertainment ticket industry in the UK. Society for Telescopy, Astronomy, and Radio, a non-profit New Jersey astronomy club. ...
Multiwavelength X-ray image of the remnant of Keplers Supernova, SN 1604. ...
Introduction The shock wave is one of several different ways in which a gas in a supersonic flow can be compressed. ...
This article or section does not cite any references or sources. ...
This gyroscope remains upright while spinning due to its angular momentum. ...
A sphere rotating around its axis. ...
“Gravity†redirects here. ...
This article is about inertia as it applies to local motion. ...
A protoplanetary disc (also protoplanetary disk, proplyd) is an accretion disc surrounding a T Tauri star. ...
Perturbation is a term used in astronomy to describe alterations to an objects orbit caused by gravitational interactions with other bodies. ...
Protoplanets are moon-sized planet embryos within protoplanetary discs. ...
The kinetic energy of an object is the extra energy which it possesses due to its motion. ...
The deuterium-tritium (D-T) fusion reaction is considered the most promising for producing fusion power. ...
General Name, Symbol, Number hydrogen, H, 1 Chemical series nonmetals Group, Period, Block 1, 1, s Appearance colorless Atomic mass 1. ...
General Name, Symbol, Number helium, He, 2 Chemical series noble gases Group, Period, Block 18, 1, s Appearance colorless Standard atomic weight 4. ...
Drawing of a T-Tauri star with a circumstellar accretion disk T Tauri stars are a class of variable stars named after their prototype - T Tauri. ...
Sol redirects here. ...
This article is about matter in physics and chemistry. ...
A protoplanetary disc (also protoplanetary disk, proplyd) is an accretion disc surrounding a T Tauri star. ...
Foucault pendulum One remarkable piece of evidence for Earth's rotation was built by physicist Léon Foucault in 1851. By attaching an iron sphere to a very long wire, Foucault constructed a pendulum that was 20 stories high. Physicists of the time knew that once a pendulum is set in motion, its direction of swing would not change. Foucault, however, observed that the direction of swing of his pendulum seemed to change. Each hour it shifted about 11 degrees in a clockwise direction. After eight hours the pendulum was swinging at a right angle to its starting direction. Because the pendulum itself could not have changed its direction of swing, Foucault concluded that the shift he saw was caused by Earth's turning beneath his pendulum. The Foucault pendulum is now a famous demonstration of Earth's rotation. ...
1851 (MDCCCLI) was a common year starting on Wednesday (see link for calendar) of the Gregorian calendar (or a common year starting on Friday of the 12-day-slower Julian calendar). ...
Simple gravity pendulum assumes no air resistance and no friction of/at the nail/screw. ...
The Clockwise direction A clockwise motion is one that proceeds like the clocks hands: from the top to the right, then down and then to the left, and back to the top. ...
Foucaults Pendulum in the Panthéon, Paris. ...
See also Image File history File links Wikibooks-logo-en. ...
Geodetic pillar (1855); Ostend, Belgium Archive with lithography plates for maps of Bavaria in the Landesamt für Vermessung und Geoinformation in Munich Geodesy (IPA North American English ; British, Australian English etc. ...
// Foundations Principles of Geology Author: Charles Lyell Publication data: 1830–1833. ...
Man has always been interested in the Earth on which he lives. ...
In Geodesy, the term Space techniques includes modern measuring methods which make use of artificial satellites, interplanetary space probes and of quasars. ...
The World Geodetic System defines a reference frame for the earth, for use in geodesy and navigation. ...
WGS 84 is the 1984 revision of the World Geodetic System. ...
In mathematics, a geodesic is a generalization of the notion of a straight line to curved spaces. In presence of a metric, geodesics are defined to be (locally) the shortest path between points on the space. ...
In physics, and specifically general relativity, geodesics are the world lines of a particle free from all external force. ...
The Earth, photographed from Apollo 17 in 1972. ...
The theories concerning the formation and evolution of the Solar System are complex and varied, interweaving various scientific disciplines, from astronomy and physics to geology and planetary science. ...
References - ^ Universal Time (UT1) and Length of Day (LOD)
- ^ Permanent monitoring
- ^ Physical effects
- ^ Chaisson, Eric J. (2005). Solar System Modeling. Cosmic Evolution. Tufts University. Retrieved on 2006-03-27.
Tufts University is a private research university in Medford/Somerville, Massachusetts, suburbs of Boston. ...
Year 2006 (MMVI) was a common year starting on Sunday of the Gregorian calendar. ...
is the 86th day of the year (87th in leap years) in the Gregorian calendar. ...
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