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mass and model
In 1911, Ernest Rutherford gave a model of the atom in which a central core held most of the atom's mass and a positive charge which, in units of the electron's charge, was to be approximately equal to half of the atom's atomic weight, expressed in numbers of hydrogen atoms.
Rutherford interpreted the gold foil experiment as suggesting that the positive charge of a heavy gold atom and most of its mass was concentrated in a nucleus at the center of the atom — the Rutherford model.
Radius – mass relations for a model white dwarf.
Solving the hydrostatic equation then leads to a model white dwarf which is a polytrope of index 3 / 2 and therefore has radius inversely proportional to the cube root of its mass, and volume inversely proportional to its mass.
When this is done, the model radius still decreases with mass, but becomes zero at M < sub > limit </ sub >.
This Fermi gas model was then used by the British physicist E. C. Stoner in 1929 to calculate the relationship among the mass, radius, and density of white dwarfs, assuming them to be homogenous spheres.
Wilhelm Anderson applied a relativistic correction to this model, giving rise to a maximum possible mass of approximately 1. 37 kg.
The above model of an oscillating mass on a spring is plausible but not very realistic: in practice, friction will tend to decelerate the mass and have magnitude proportional to its velocity ( i. e. dx / dt ).
The simplest model for this that is in general agreement with observed phenomena is the Cold Dark Matter cosmology ; that is to say that clustering and merging is how galaxies gain in mass, and can also determine their shape and structure.
As one examines suitable model spacetimes ( either the exterior Schwarzschild solution or, for more than a single mass, the post-Newtonian expansion ), several effects of gravity on light propagation emerge.
Also, most model builders simply assume supersymmetry because it solves the hierarchy problem — i. e., it stabilizes the electroweak Higgs mass against radiative corrections.
The harmonic oscillator model is very important in physics, because any mass subject to a force in stable equilibrium acts as a harmonic oscillator for small vibrations.
Every law, every letter, every syllable of inflection in the different languages was illustrated by an almost exhaustive mass of material, and it has served as a model for all succeeding investigators.
Along the same lines, David Baron of Stanford GSB presents a game-theoretic model of mass media behaviour in which, given that the pool of journalists systematically leans towards the left or the right, mass media outlets maximise their profits by providing content that is biased in the same direction.
According to this model, most views within society are freely expressed, and the mass media are accountable to the people and tends to reflect the spectrum of opinion.
Using the propaganda model, Manufacturing Consent posits that corporate-owned news mass communication media — print, radio, television — are businesses subject to commercial competition for advertising revenue and profit.
Herman and Chomsky's " propaganda model " describes five editorially distorting filters applied to news reporting in mass media:
In this model we consider a particle as being a point of mass which describes a trajectory in space which is modeled by a function giving its coordinates in space as a function of time.
: Note this model assumes the particle is a point mass, which is certainly known to be false in many cases in which we use this model ; for example, as a model of planetary motion.

mass and white
This tissue gives bones their smooth, white, and solid appearance, and accounts for 80 % of the total bone mass of an adult skeleton.
The apple trees were a mass of pink and white, and the lilac trees were in blossom.
The Chandrasekhar limit () is the maximum mass of a stable white dwarf star.
If a main-sequence star is not too massive ( less than approximately 8 solar masses ), it will eventually shed enough mass to form a white dwarf having mass below the Chandrasekhar limit, which will consist of the former core of the star.
This fate may befall carbon-oxygen white dwarfs that accrete matter from a companion giant star, leading to a steadily increasing mass.
It has been inferred that as the white dwarf's mass approaches the Chandrasekhar limit, its central density increases, and, as a result of compressional heating, its temperature also increases.
According to a group of astronomers at the University of Toronto and elsewhere, the observations of this supernova are best explained by assuming that it arose from a white dwarf which grew to twice the mass of the Sun before exploding.
The super-Chandrasekhar mass white dwarfs that have originated these supernovae are believed to have had masses up to 2. 4-2. 8 solar masses.
Discusses how to find mass-radius relations and mass limits for white dwarfs using simple energy arguments.
The behavior of a star now depends on its mass, with stars below 0. 23 solar masses becoming white dwarfs directly, while stars with up to ten solar masses pass through a red giant stage.
In astrophysics, mass transfer is the process by which matter gravitationally bound to a body, usually a star, fills its Roche lobe and becomes gravitationally bound to a second body, usually a compact object ( white dwarf, neutron star or black hole ), and is eventually accreted onto it.
In spite of their violence, the amount of material ejected in novae is usually only about of a solar mass, quite small relative to the mass of the white dwarf.
The recurrence interval for a nova is less dependent on the white dwarf's accretion rate than on its mass ; with their powerful gravity, massive white dwarfs require less accretion to fuel an outburst than lower-mass ones.
Once they have exhausted their supply of hydrogen through nuclear fusion, medium to low mass stars shed their outer layers to form a planetary nebula and evolve into white dwarfs.
While most clusters become dispersed before a large proportion of their members have reached the white dwarf stage, the number of white dwarfs in open clusters is still generally much lower than would be expected, given the age of the cluster and the expected initial mass distribution of the stars.
Recent astrophysical models suggest that red dwarfs of 0. 1 solar mass may stay on the main sequence for some six to twelve trillion years, and take several hundred billion more to slowly collapse into a white dwarf.

mass and dwarf
knowing that its ageless mass would always dwarf the short span of time allotted to any man.
2MASS J044144 is a brown dwarf with a companion about 5 – 10 times the mass of Jupiter.
A study of 27 Milky Way neighbors found that in all dwarf galaxies, the central mass is approximately 10 million solar masses, regardless of whether the galaxy has thousands or millions of stars.
The values of luminosity ( L ), radius ( R ) and mass ( M ) are relative to the Sun — a dwarf star with a spectral classification of G2 V. The actual values for a star may vary by as much as 20 – 30 % from the values listed below.
If the core of the star is not too massive ( less than approximately 1. 4 solar mass, taking into account mass loss that has occurred by this time ), it may then form a white dwarf ( possibly surrounded by a planetary nebula ) as described above for less massive stars, with the difference that the white dwarf is composed chiefly of oxygen, neon, and magnesium.
A star with a core mass too great to form a white dwarf but insufficient to achieve sustained conversion of neon to oxygen and magnesium, will undergo core collapse ( due to electron capture ) before achieving fusion of the heavier elements.
After leaving the main sequence, Vega will become a class-M red giant and shed much of its mass, finally becoming a white dwarf.
If the mass of the progenitor is above 8 solar masses but below 10. 5 solar masses, the core temperature suffices to fuse carbon but not neon, in which case an oxygen-neon – magnesium white dwarf may be formed.
The physics of degeneracy yields a maximum mass for a non-rotating white dwarf, the Chandrasekhar limit — approximately 1. 4 solar masses — beyond which it cannot be supported by electron degeneracy pressure.

0.211 seconds.