Also, planetary gravitational attraction increases the dust concentration near the plane of the ecliptic as the sun is approached.

In fact, the concavity of the water clearly involves gravitational attraction, and by implication the Earth also is a participant.

In continuum mechanics a body is considered stress-free if the only forces present are those inter-atomic forces ( ionic, metallic, and van der Waals forces ) required to hold the body together and to keep its shape in the absence of all external influences, including gravitational attraction.

The oblate spheroid shape reflects, following Clairaut's theorem, the balance between containment by gravitational attraction and dispersal by centrifugal force.

Unlike baryonic dark matter, nonbaryonic dark matter does not contribute to the formation of the elements in the early universe (" Big Bang nucleosynthesis ") and so its presence is revealed only via its gravitational attraction.

In comparison with the much weaker gravitational force, the electromagnetic force pushing two electrons apart is 10 < sup > 42 </ sup > times that of the gravitational attraction pulling them together.

As well as helping determine the parallax of 61 Cygni, Bessel's precise measurements allowed him to notice deviations in the motions of Sirius and Procyon, which he deduced must be caused by the gravitational attraction of unseen companions.

Associations of galaxies can overcome this expansion on a local scale through their mutual gravitational attraction.

When observed visually, clusters appear to be collections of galaxies held together by mutual gravitational attraction.

However, if an object located at the point drifted closer to one of the masses, the gravitational attraction it felt from that mass would be greater, and it would be pulled closer.

This same effect is present at the Lagrangian points in the Earth – Moon system, where the analogue of the string is the summed ( or net ) gravitational attraction of the two masses, and the stone is an asteroid or a spacecraft.

is slightly unstable ( see stability, above ) because drifting towards the Moon or Earth increases one gravitational attraction while decreasing the other, causing more drift.

He found that de Lacaille had failed to take into account the gravitational attraction of the nearby mountains.

This discrepancy may be due to the gravitational attraction of Jupiter, which acts as a kind of barrier, trapping incoming comets and causing them to collide with it, just as it did with Comet Shoemaker – Levy 9 in 1994.

They are loosely bound to each other by mutual gravitational attraction and become disrupted by close encounters with other clusters and clouds of gas as they orbit the galactic center, resulting in a migration to the main body of the galaxy as well as a loss of cluster members through internal close encounters.

In contrast, the more massive globular clusters of stars exert a stronger gravitational attraction on their members, and can survive for many billions of years.

Herschel conceived the idea that stars were initially scattered across space, but later became clustered together as star systems because of gravitational attraction.

File: Cavendish-walk. jpg | Henry Cavendish ( 1731-1810 ): greatest English chemist and physicist of his age, researched composition of the atmosphere, the properties of different gases, the synthesis of water, the law of electrical attraction and repulsion, a mechanical theory of heat, calculated the weight of the Earth in the Cavendish experiment, determined the universal gravitational constant

This sort of colony would be especially suitable for Saturn, Uranus and Neptune for which the gravitational attraction at the altitude of the visible atmosphere is near one Earth gravity.

The Earth and Moon rotate about their common center of mass or barycenter, and their gravitational attraction provides the centripetal force necessary to maintain this motion.

He waited until 1802 ( in Catalogue of 500 new Nebulae, nebulous Stars, planetary Nebulae, and Clusters of Stars ; with Remarks on the Construction of the Heavens ) to announce the hypothesis that the two stars might be " binary sidereal systems " orbiting under mutual gravitational attraction, a hypothesis he confirmed in 1803 in his Account of the Changes that have happened, during the last Twenty-five Years, in the relative Situation of Double-stars ; with an Investigation of the Cause to which they are owing.

: The gravitational attraction force between two point masses is directly proportional to the product of their masses and inversely proportional to the square of their separation distance.

This includes electronic noise, but can also include external events that affect the measured phenomenon — wind, vibrations, gravitational attraction of the moon, variations of temperature, variations of humidity, etc., depending on what is measured and of the sensitivity of the device.

After a rough estimate of the perturbations the comet would sustain from the gravitational attraction of the planets, he predicted its return for 1758.

Although the Af calculation is obvious by analogy with that for gravitational field and osmotic pressure, it is interesting to confirm it by a method which can be generalized to include related effects.

Indeed, the International Committee for Weights and Measures ( CIPM ) notes that " its definition applies only within a spatial extent sufficiently small that the effects of the non-uniformity of the gravitational field can be ignored.

Similarly, the total mass inside a sphere containing a black hole can be found by using the gravitational analog of Gauss's law, the ADM mass, far away from the black hole.

* Caustics may occur in simple models of gravitational collapse, and can appear to lead to singularities.

* Computer models of gravitational collapse have shown that naked singularities can arise, but these models rely on very special circumstances ( such as spherical symmetry ).

The gravitational redshift of a photon can be calculated in the framework of General Relativity ( using the Schwarzschild metric ) as

If the observer is at a lower gravitational potential than the source, a gravitational blueshift can be observed instead.

It was shown that the relativistic gravitational interaction arises as the small-amplitude collective excitation mode whereas relativistic elementary particles can be described by the particle-like modes in the limit of low momenta.

The bending of light by gravity can lead to the phenomenon of gravitational lensing, in which multiple images of the same distant astronomical object are visible in the sky.

But using different assumptions about the special-relativistic frames ( such as their being earth-fixed, or in free fall ), one can derive different predictions for the gravitational redshift, that is, the way in which the frequency of light shifts as the light propagates through a gravitational field ( cf.

Matching the theory's prediction to observational results for planetary orbits ( or, equivalently, assuring that the weak-gravity, low-speed limit is Newtonian mechanics ), the proportionality constant can be fixed as κ = 8πG / c < sup > 4 </ sup >, with G the gravitational constant and c the speed of light.

Additionally, it can be shown that any massless spin-2 field would give rise to a force indistinguishable from gravitation, because a massless spin-2 field must couple to ( interact with ) the stress-energy tensor in the same way that the gravitational field does.

Since this gas is in approximate hydrostatic equilibrium with the overall cluster gravitational field, the total mass distribution can be determined.

The holographic principle is a property of quantum gravity and string theories which states that the description of a volume of space can be thought of as encoded on a boundary to the region — preferably a light-like boundary like a gravitational horizon.

A neutron star is a type of stellar remnant that can result from the gravitational collapse of a massive star during a Type II, Type Ib or Type Ic supernova event.

This understanding is particularly useful for mathematical analysis, because the object's motion can be described as the sum of the three one-dimensional coordinates oscillating around a gravitational center.

A stationary body far from another can do external work if it is pulled towards it, and therefore has gravitational potential energy.

Orbits can decay via the emission of gravitational waves.

There are many physical constants in science, some of the most widely recognized being the speed of light in vacuum c, the gravitational constant G, Planck's constant h, the electric constant ε < sub > 0 </ sub >, and the elementary charge e. Physical constants can take many dimensional forms: the speed of light signifies a maximum speed limit of the Universe and is expressed dimensionally as length divided by time ; while the fine-structure constant α, which characterizes the strength of the electromagnetic interaction, is dimensionless.

However, even this enormous rigidity can be overcome by the gravitational field of a massive star or by the pressure of a supernova, leading to the formation of a black hole.

The first such gravitational lens to be discovered was the double-imaged quasar Q0957 + 561 ( or Twin Quasar ) in 1979 A grouping of two or more quasars can result from a chance alignment, physical proximity, actual close physical interaction, or effects of gravity bending the light of a single quasar into two or more images.