Gravitational attraction

In addition to friction, which is often confused with adhesion, there are several other phenomena which give attraetions between bodies. These phenomena can therefore mix up the issues of moleeular adhesion. As Newton wrote the attractions of Gravity, Magnetism and Electricity reach to very sensible distanees, and so have been observed by vulgar Eyes, and there may be others whieh reaeh to so small distances as hitherto escape observation.  

Although it appears from this calculation that we can ignore the gravitational force, there is a subtle influence of gravity which has a large adhesive effect. 

It is obvious that this suction effect is not true molecular adhesion. Suction pads work better as you dive beneath the ocean where the gravitational pressure increases. But they get worse as you climb a mountain, eventually becoming useless in space. Molecular adhesion should remain the same, at the bottom of the sea or out in space, independent of gravitational effects. 

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Isaac Newton modestly claimed to have stood on the shoulders of giants to explain how he was able to achieve his outstanding discoveries in the fields of gravitational attraction and planetary motion our Giants in the field of electromagnetic induction would probably have said the same. 

In the usual situation illustrated in Fig. XIII-6 the particle is supported at a liquid-air interface against gravitational attraction. As was seen, the restoring force... 

Fusion of a nucleus of with one of helium gives 0 Eventually the helium too becomes de pleted and gravitational attraction causes the core to contract and its temperature to increase to the point at which various fusion reactions give yet heav ler nuclei... 

Weight. A measure of the force exerted on a body of mass M by the gravitational attraction of the earth. The magnitude of this force is... 

The blanket of air that cloaks our planet behaves as an ideal gas, but the atmosphere is bound to the Earth by gravitational attraction, not by confining walls. The pres-sure exerted by the atmosphere can be thought of as the pressure of a column of air. Just as the pressure exerted by mercuiy in a barometer is the pressure of the column of mercury. The higher we rise into the atmosphere, the less air there is above us. Less air above us means that the pressure exerted by the column of air is lower. Lower pressure, in turn, means lower molecular density, as indicated... 

Big Bang nucleosynthesis produced only H and He atoms with a little Li, from which nuclei the first generation of stars must have formed. Large clouds of H and He when above the Jeans Mass condensed under the influence of gravitational attraction until they reached the temperatures and densities required for a protostar to form, as outlined. Nuclear fusion powers the luminosity of the star and also results in the formation of heavier atomic nuclei. 

A new reservoir of comets may have formed at around 5 AU in a local orbit around Jupiter or at least perturbed by its gravitational attraction. A comet close to Jupiter would simply have been captured, delivering its chemical payload to the ever-increasing gas giant. Some comets would merely have been deflected towards the inner terrestrial planets, delivering a similar payload of water and processed molecules. Cometary impacts such as the spectacular collision of the comet Shoemaker-Levy 9 with Jupiter would have been common in the early formation phase of the solar system but with a much greater collision rate. Calculations of the expected collision rate between the Earth and potential small comets deflected from the snow line may have been sufficient to provide the Earth with its entire... 

Black hole A sufficiently heavy mass the will not allow a photon and hence light to escape as a result of its gravitational attraction. 

The term "affinity" has its roots in very old ideas to the effect that like attracts like and that bodies combine with other bodies because of mutual affection or affinitas. This meaning is employed in Etienne Francois Geoffroy s Table des differents rapports observes entre differentes substances (1718) for replacement reactions.28 However, in the middle of the eighteenth century, Boerhaave spoke of the affinity of a substance for others unlike it, giving the word "affinity" a new meaning. Boerhaave interpreted Geoffroy s table as a representation of Newtonian-type forces of gravitational attraction or electrical attraction and repulsion.29... 

The relative molecular mass of a molecule is the sum of the atomic masses of its constituent atoms. The term has replaced molecular weight because weight is a parameter that depends on the magnitude of gravitational attraction. Since relative molecular mass is a ratio (of the mass of the molecule to one-twelfth of the mass of the carbon-12 atom) no units are required. It has, however, become accepted practice to use daltons as a unit of molecular mass, commemorating John Dalton s atomic theory of matter. Relative molecular mass is an approximate indication of size a spherical molecule of 5000 ddtons (or 5 kDa) has a diameter of approximately 2.4 nm. 

Let r be the orbital radius, m the mass of a test object, and M r) the mass of that part of the galaxy lying within radius r. The equation describing equilibrium between gravitational attraction and centrifugal force is... 

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