The stability of the matter
The introduction by Newton of a fundamentally attractive force opened the debate on the origin of the stability of the matter. The reconciliation of the macroscopic and the microscopic by the thermodynamics and rationalization of the classification of the chemical elements are going to lead to the reinventing of atoms and in their experimental confirmation. But the prediction of their properties is going to lead to a fundamental revolution: the quantum physics.
We shall describe the modern vision of the atom such as brings it to us this necessary modelling of the Nature. Then we will display the process which allows to reconstitute the various atoms, how the model also allows to reconstruct molecules and how to find the conductive properties of the matter.
We shall describe then the following scale, the organization of the atomic nucleus and the principles which assure its stability without describing however the models of forces envisaged for the inside of the particles of the nucleus.
Finally we will recapitulate the forces in game in the various scales
to assure the balance of bodies.
1 Questions of principles*
2 A new world: the atom *
3 How to rebuild the Mendeleev table *
4 Of The Waves and Molecules *
5 A stable nucleus *
Scale of stability and scales of the forces*
1 Questions of principles
The discovery of the fundamental and universal forces began with the gravitation. The law which describes it is said universal because it applies to all the scales. It concerns however the gravity the structure of planetary systems and it is the assimilation of the orbit of the Moon in a perpetual fall which revealed to Newton the universality of the law of attraction.
It was initially conceived as a force, fundamentally attractive because connected with the quantity of matter, and never nullifying with the distance.
What characterizes fundamentally this force is that the attraction of a spherical mass is equivalent to the attraction of the center affected by the same mass; the force is spherical. Newton's law is a particular case of this general property because the force decreases with the square of the distance in the attractive mass there. As a consequence, it is conservative that is that, for any surface centred on the source of gravitation, the stream of energy remains constant. In the general case it would be necessary to add to this law a proportional term at the distance and the proportional factor is said cosmological constant.
The vision of classic time is that of a static, existing universe of any time.
Globally, any direction privileged in the distribution of matter or any movement would lead its collapse by the gravitation, unless admitting that the introduced cosmological constant higher is not equal to zero engendering a repulsive force which would come to compensate for the gravitational attraction. But historically, Newton discovered this general shape of the spherical law leave and he had to suppose an infinite universe to admit that the universe does not collapse or to introduce a divine hand perms.
This problem was resolved by the introduction in the twenties of a dynamic universe, the distances between bodies varying universally according to the same for a while given rate of expansion, the time being represented by an axis the origin of which is merged with a moment of total creation (space / time / energy): Big-Bang.
But that is it of the local stability? The stability of a system formed by planets attracted by a massive central body implies the existence of forces of balances to resist to its collapse; they are the centrifugal forces connected to the inertia of satellites in rotation around the central body.
In fact in a realistic system in N body influencing each other the stability of the system is related to the long-term convergence of the disturbances, the stability which seems assured only for the most massive, the lightest bodies, as maybe our Earth, risking the eviction with more or less long term.
The force of attraction, in Newton's theory, exercises in a vacuum; the support which transports the effect of the force is not thus explicit. It is about an action at distance not explained in its foundations. It bases on a notion of mass independent from its state of movement, from its speed or from its direction. It depends only on the distance between bodies. Any modification of the distribution of the mass in the space has an immediate effect on the force applied to the body of test. This momentariness is an idealized image.
So got this strange notion of ether: a perfectly transparent space and which nevertheless broadcasts mechanically and immediately all the movements.
The force of gravitation thus seems adapted to the description in the first order of the movements of bodies; it is only an estimate.
She would not also know how to explain the existence of the condensed and stable matter which surrounds us. The stability of bodies, that they are tiny or global, requires the introduction of new forces which they would be repulsive. The notion of negative or positive charge so appears.
Historically, things were not nevertheless so simple because the other false notions got. For example the famous notion of " nothing gets lost, nothing builds up itself, everything is transformed " said Lavoisier (a perfectly coherent notion with an existing static universe of any eternity).
When he considered the phenomenon of the heat, he associated it to an element in the same way as the other chemical elements, the physical experiences be only measuring the decanting while verifying the global conservation. The heat is seen as a fluid and, according to a version of this theory, as a vibration of this fluid which interfering in any chemical body prevented the collapse from it under its mechanical action.
The XIXth century saw major breakthrough which destroyed this notion: it was first of all the discovery by Carnot of the first principle (in a completed system the useful work is equal to the quantity of lost heat), followed by the introduction by Clausius by the notion of irreversibility and entropy, the reintroduction of the notion of atom by coherence with the laws of pressure (Dalton, Avogadro) and the chemical synthesis (Table of Mendeleïev); the heat could not be any more a universal fluid; it was identified with the cumulative kinetic energy of the tiny bodies.
We returned to the initial question there: that what is what maintains stable a matter condensed but formed by indivisible and different elementary bodies?
The XIXth century, from Volta to Marconi, was also that of the progressive discovery of the electricity, its links with the magnetism and with the light.
Maxwell introduced the notion of field (which can be seen by the arrangement of the iron filings around a magnet), that is the intensity and the orientation completely of the space of a field of force engendered by a source of field. He ends in the conclusion that the light is a state of excitement of an electromagnetic field, the vibrations being transverse with regard to the direction of distribution. The vibrations of the field ( the light) could propagate in the space by auto-induction enter the electric and magnetic field
It appeared as well as the almost infinite collections of atoms (the number of Avogadro, the report between a macroscopic mass and an atomic mass, is disproportionate) found their stability only through the forces of aversion that atoms and molecules exercised the some on the others through loads of the same sign.
Rutherford discovered the notion of atomic nucleus by observing that particles alpha (in fact of the nucleus of helium) emitted by natural destruction of the radioactive bodies were in a proportion of one ten thousandth strongly diverted by the interposition of a golden sheet, the others crossing it in a straight line; the nucleus of helium were repelled by nucleus of gold; in all the nucleus were thus affected a positive charge.
The simplistic model of atoms appeared then as a planetary system the central load of which is surrounded with opposite loads which we identified with electrons that is in beams emitted by a cathode (negative pole of a pile).
But the problem was pushed away by a notch: how did the central load and the peripheral loads of the atom make not to get closer quickly until collide?
Indeed the electron possesses an electric load and should shine in its movement of rotation around the nucleus, unlike a satellite which moves around the central celestial body without loss of energy. The radiation should engender the loss of speed of the electron and its fast fall on the nucleus. Now atoms are stable.
How also to explain the stability of positive charges grouped together in the nucleus and all the bigger as the body is complex and thus taken away in the table of Mendeleïev?
And how explain this spectre of lines which arose when we studied the
radiation emission of atoms subjected to an excitement? The light seemed
emitted according to definite frequencies, the continuous spectre of the
cathodic beams ( the free and accelerated electrons) leaving place with
a discreet spectre for atoms..
2 A new world: the atom
It was then necessary to introduce notions qualitatively different from classic paradigms, note which showed themselves heart-rending for number of taken physicists between their traditional predictible conception of the world and the descriptive efficiency of the new model.
According to the new notions, the process of measure attributed a value result by operating a selection among potential values. The quantum mechanics formalize under the name of observable the possible results of the measures on an object. It is not a description of the object in itself.
The quantum mechanics resolve the problem of the stability of the matter because it completes the corpuscular description of the matter by its undulatory behavior. The particle appears to us as a vast object, as a wave, and is not absolutely localizable any more.
The quantum mechanics thus deal with fundamentally imperceptible objects, because similar and not absolutely localizable, its statistics is thus qualitatively different from the probability statistics on the macroscopic objects.
The phenomena of disorder in classic physical appearance are associated to combinations raised by object on determinist laws, combinations which engender an unpredictability treated by the probability. But the probability interpretation of the quantum mechanics is imposed by observable phenomena on intrinsically unpredictable character and where the no-separability engenders mixing of states.
The equation of the function of wave of Schrödinger allows to find the still waves in a space, that is the waves which in an atom wind on themselves by keeping their phases what avoids that they destroy themselves themselves by interference.
We do not know how to associate any more as in classic mechanics, a wave in every particle but a function of wave which represents the global evolution of N particles composing the system (typically the electrons of an atom).
The evolution of this wave is made in a space of configuration which associates 3 new dimensions to every particle adding to the system.
In quantum mechanics the functions of wave of the quantum states are operations of a symmetry of the quantum object taken globally. This global geometrical symmetry of the atom (and thus not localizable) is associated to numeric harmonies and thus to multiplicities according to integers. She also allows to select the solutions existing physically among the mathematical solutions of the functions of waves. The geometry is a shape of knowledge not descriptive but selective. It is the shape which forces the matter.
This geometrical invariance is bound to invariances of physical quantities.
It is necessary to underline that this notion of unique electron described by a function of wave applies moreover only for the hydrogen and that the description for more complex atoms bases on a description of combined electrons and thus which cannot be not individualized.
An essential point is that the equation of Schrödinger in itself does not allow to find exactly the states of energy for atoms in several electrons. If it had been the case, atoms would be directly distinguished each other, much more stable than in the reality; the matter would be crushed. It is the reintroduction of symmetries that allows to find the road of the real description of atoms.
It is thus necessary to add a postulate, admitted but not proved; the physically acceptable functions of wave have to give opposite results if we invert the variables of position of the electrons of the system and the variables related to their moments of intrinsic rotation. We shall return farther on this last notion.
The atom of hydrogen is totally determined by 3 quantum numbers its energy ( the number n ), by kinetic orbital moment (number p), and by the projection of this moment on the direction of the magnetic field which serves for testing the orbital moment led on the atom (number m).
Once again, it is not the atom which we characterize in itself but what we can say about it when we subject it to a measure, for example to a magnetic field.
In the electric field of the nucleus, the electron is, at least to express an analogy, in a more and more narrow conical well.
The nucleus attracts the electron, the wave associated to the electron becomes still by reflection on the limits of the well. When the electron sinks, the still wave is reduced as a spring for which we would try to push. The maximal state of reduction is the lowest, stable state in energy of the atom.
Unlike the macroscopic physics where the stable state is characterized by the absence of movement, in quantum physical appearance(physics), there is always an inflexible movement in a temperature of 0 kelvin.
Another equivalent perspective is to consider the duality wave-particle. It was introduced by the experience of Young. A bundle of light or particles aims at a screen. We interpose another screen with one or two slits. In the case of a simple slit a bundle of light produces a concentric bundle around the impact point. In the case of a double slit, interferences are produced on the final screen, the combination of sub-bundles reemitted by both slits products, and this even if we send corpuscles one by one.
The duality wave-corpuscle says to us that it is totally vain to try to determine by which slit the corpuscle is crossed. When we try to discriminate between these two roads, by the lighting by a bundle of photons for example, and when we reach the threshold allowing the discrimination there is abolition of the interference; the wave becomes again particle. In fact, it is not possible to localize a wave.
If we determine the present position (by which slit do we cross), we have a total indecision on the future state of the particle; it does not contribute anymore to the future image and there is abolition of the interference.
If we agree not to know, in this particular case not to determine the position, we know exactly which is the impulse and that it will contribute statistically to the forming of the fringe of interference.
The duality wave-particle implies that the tiny bodies supply to the experimenter only not simultaneous measures of couples of macroscopic notions: position versus impulse. In this couple we can associate an equivalent couple; we cannot have a totally precise knowledge of the energy of a system and determine exactly at which moment in the time the measure was obtained.
The stability of atoms thus base on an uncertainty on the position of electrons; an electron cannot be confined in a very reduced zone towards the nucleus at the risk of increasing the variation of its impulse what increases the probability to see it going away from the nucleus
At the same time, the measure clarifies some energy of an electron we made give up clarifying its position in the time; the place on the trajectory of the electron is indistinct.
The states of electrons described by the function of wave correspond to the various levels of energy. An electron can get excited by the coupling between its own electric field and an excitement of an external electric field (absorption of a photon which is a state of vibration of an electromagnetic field).
At the same time, an electron by interacting with the electromagnetic field of the atom can re emit a photon and disexcite.
But why could we not assimilate the electron to a wave only the harmonious of which would be stable, little as the vibrations of a rope of violin?
This notion would be misleading because if she explains intuitively that the electron is not localizable (a wave has no fixed place, only its intensity varies in the space without limitation of extension) it would not agree nevertheless either in the notion of localizable electron during a projection on target particles, or in the notion of combination of electrons which describes atoms more complex than hydrogen. Besides how to attribute properties of sources of electric load or attribute of quantum numbers to a pure wave? A source of field must be localizable in the space.
It is thus advisable not to replace a false notion by the other one by evoking electronic waves because these are only distributions of the probability of appearance of punctual particles, it is vain to speak also about a not punctual matter).
In fact the wave of the electron in an atom wraps the nucleus, immersed in its electric field. The wave possesses modes of vibration and the stable waves are going to form the discreet spectre of the energies, by leaving the fundamental and by describing all its harmonious, of energy more and more weak until the energy of connection no characterizing the ionization.
The electron can pass from a mode to the other one by interacting with the electric field. The change of mode comes along with a change of electric potential energy, the difference determining the energy of the photon, the particle of light which is only an excitement automobile maintained by the electromagnetic field. To simplify the electric field of the atom, characterized locally by the energy of electrons, modifies by addition or subtraction of an object which is only an autonomous vibration of field: the photon.
What is the fundamental level of the atom? Let us adopt a sight simplified on base of classic concept. This fundamental level is characterized by the fact that the increase of the kinetic energy of the atom by the increase of the orbital frequency eventually exceeds the gain of electrical energy due to the link of the positive nucleus and the negative electron.
The electron possesses then its most negative energy (the most tight state because it is necessary to bring a work, a positive energy to free the electron and the nucleus).
The distance between the electron and the nucleus distributed statistically around a characteristic shelf of every level of energy.
The uncertainty on its actual distance is coupled with a total uncertainty on the angle of the electron with regard to a reference axis; we do not know in which sense turns the electron, its kinetic moment is thus equal to zero, what takes away definitively this model of that of a global body.
In fact, the electron is not subjected to a stable kinetic energy but possesses an average impulse determined by the relation of uncertainty which connects position and impulse.
What characterizes in a clarify way the electron, they are its modes of vibration, the classic values position, impulse not supplying more than a beach of statistical variation.
But an electron living on a superior layer is unstable and could fall at a lower level by emitting a photon. This is made impossible by the principle of exclusion from Pauli which implies that two particles as electrons can occupy the same quantum state.
The demonstration of this principle bases on what we sometimes name the second quantification; not only the states of particles are quantified but the particles which characterize the fields of interaction they also answer a quantification.
The completion of the various possible states forms the electronic layers which are stable and the only states which an electron can occupy by a transition are associated to layers incompletely filled.
A set of electrons cannot thus merge to form an electronic wave which is macroscopic and coherent. This property is true of all the particles source of field (or particles of matter). These waves were thus discovered late because they thus show themselves only at the tiny level.
On the contrary, the particles which convey fields can merge (such the photons of light) to form coherent waves (a bundle laser in an ideal case). It is so evident as the light possesses a property of accumulation because it is the product of the combination of waves which possess the same properties and it is visible because it carries a field with reach unlimited.
But where from comes this distinction between merging corpuscles or not?
The equation of wave of Schrödinger allows to determine the intermittent levels of energy of the stationary waves in the particles of the atom.
Now to make coherent this equation with those of the relativity who couple drainage of time and movement in the space, we end in two new types of equation of wave.
The first equation describes the particles which possess a movement of intrinsic rotation, the spin. This intrinsic movement produces a field which interacts with the field produced by the movement of the particle. So the electron leads a magnetic field which interacts with that caused by its movement in the electric field the source of which it is.
Other equation describes a type of particle without spin, such the photon of light; particle not subjected to a coupling between an intrinsic field and a field leads by their movement.
Particles of matter, subjected to the law of exclusion from Pauli possess half-whole spins (3/2, 1/2,1/2, 3/2): they are closed because subjected to the statistics of Fermi-Dirac (they are distinguishable by their numbers or different quantum attributes).
The vector particles of the fields of interaction and being able to form coherent waves belong to spins integers ( 0,1,2 ): they are bosons subjected to the statistics of Bose-Einstein (they are not distinguishable).
In fact with very low temperature, particles in spins half-integers can group by two, forming then coherent waves of boson type and engendering phenomena of abolition of shocks during the distribution ( supraconductivity ) and during the abolition of viscosity (superflow).
A classic wave is translated by a movement of matter and is characterized by parameters of amplitude, frequency and phase as well as by a speed of propagation. The existence of a limit of classic wave is associated to the fact that photons are bosons. There is no similar classic limit for the electrons which are closed. They are not waves as we usually conceive them.
The speed of propagation concerns in both cases only the aspect particle. It is associated to a coupling between the particle and the space characterized by a scalar factor because independent from the orientation: the mass. It is only the aspect particle which propagates in a lower or more equal speed in c.
In both cases, bosons or closed, the quantum wave is not local and is
not thus related to a notion of speed of propagation of the wave: if the
result of a measure on a particle is unpredictable, the result of the measure
select globally the wave in a particular state. If we have two coupled
particles, they are subjected to the same function of wave; the state of
the second particle will be simultaneously modified with the measure of
the first particle. The act of measure in a place literally created both
coupled but separate particles spatially.
3 How to rebuild the Mendeleev table
It is impossible to calculate exactly the solutions of the equation of Schrödinger for atoms except for the hydrogen.
An approached model consists in treating every electron as if it interacted with a pseudo nucleus formed by the actual nucleus and the other electrons. But these apparently independent electrons are only models called quasi--electrons. We can clarify that it is about a model of second level; the vision of the electron as an autonomous entity, while it is bound to the atom, recovers too from the estimate of the quantum model which considers that the function of wave exists only at the level of the atom.
The function of total wave of the atom is all the n orbitales for n quasi--electrons. It is antisymmetric what implies that n orbitales is different but on the other hand quasi--electrons must be imperceptible; it is not thus possible that every orbit governs its own quasi-electron: the properties of quasi--electrons result from the combination of all the orbits.
The orbital plan of the atom is a stair called successively: 1s, 2s, 2p.... Characterized each by a particular value of the triple quantum numbers n, l, m.
The various layers describe the discreet states of the orbital impulse which is characterized by forms different from the cloud representing the density presence of the electron (in sphere around the nucleus, in eight, in clover)
We place quasi--electrons on orbits. An antisymmetry of the function of wave is translated by the fact that only 2 quasi--electrons of spins opposite can occupy an orbit.
The excitement of the atom is described as the jump of the quasi-electron between 2 orbits. But in the physical reality, the excitement of the atom modifies simultaneously the state of all the electrons of the atom.
To reconstitute the table of elements Mendeleïev, we fill orbits by applying the principle of Pauli (2 quasi--electrons in spin set by orbit) and the rule of Hund: quasi--electrons have to occupy the maximum of orbits of the same energy.
The physical and chemical properties are visible functions of the atomic weight. In fact the classification of Mendeleïev lists atoms in the increasing order of their electrons and groups atoms in plans with similar orbit, that is possessing for the successive columns 0,1,2,3 quasi--electrons not mated on the most external layer.
This classification is the reflection of properties of a symmetry.
The World is a music of Pythagor, the World is harmony.
4 Of The Waves and Molecules
Atoms assemble in the form of molecules. Only the quantum mechanics manage to report the structure and the properties of molecules.
It is necessary to deviate from the simplified image where molecules are only a mechanical assembly being exchanged particles (electrons) to assure their connection.
The number of connections that the atom can form is its chemical valency which is made by a pooling of more or less localizable electrons (it is not of the ping-pong). This allows to reconstruct, at the level of the molecule, models of orbits occupied by quasi--electrons.
The functions of wave of these orbits represent the operations of a symmetry of the molecule and are delocalized on all the molecule.
The molecular stability is guaranteed by the coupling of all the quasi--electrons by pair. The association generates some heat because the molecule possesses a level of energy lower than the separate atoms.
The foreseen and calculable phenomena by the quantum mechanics base on no internal and explicit physical mechanism. Mathematically the identical orbits of 2 atoms forms 2 new orbits: one of the lesser energy and thus more stable, the other one more incited. This model is similar to that of 2 similar oscillating circuits which are going to form 2 different echos.
In the case of multi-atomic molecules, the mean value of the load completely created so much double electronic load as there is of chemical connections, load engendered by all the orbits of this molecule occupied by quasi--electrons.
The relocation of the load does not allow to affect explicitly a pair of electron by connection.
The location of electrons not bound to atoms depends on the degree of order of the environment.
In a perfectly ordered environment, all the electronic waves add their effects where from a spread stationary wave and the absence of location.
In a perfectly disordered environment, the waves destroy themselves by interference except regions of location. The free waves can even change nature and future of the harmonious waves in the wells of energy of atoms.
The particular groupings of the chemistry (acid, base, alcohol, ester, amino acid) so correspond to specific properties produced by the partial relocation of the electronic waves.
In numerous examples where several electronic loads are involved, as in the covalency connections, loads are not localizable but not distributed (a typically quantum notion). It is notably the case of the water, proving the cowardly link enter the proton of both atoms of hydrogen and their electrons where from the property of hydrophily, of aggregation of the molecules of water between them, and thus its remarkable properties of solvent. More exactly, the atom of oxygen is engaged in two connections with both atoms of hydrogen and the density of presence of electrons is more important towards the oxygen. But it remains two free orbits on both sides of the molecular plan on the opposite site in the atoms of hydrogen. These free pairs can engage a connection with an atom of hydrogen partially deprived of its electron of the another molecule of water.
The properties of relocation also justify the structure of the benzene where six electrons are in the center of a crown of atoms but do not exist as such because the global load is distributed on all the orbit.
The principle of molecular orbits extends in the crystalline structures organized on macroscopic distances.
Seen the considerable number of implied electrons (or of quasi--electrons on orbit), orbits is so dense as they are grouped in bands.
The quantum states lead to the figures of diffraction of the electronic waves in the crystalline network. The distribution of bands thus follows an organization which reflects this macroscopic property.
Bands are filled by quasi--electrons according to the same rules as for molecules and atoms.
We find insulations in case the bands of valency and conduction are very separate.
In the case of the drivers bands are in the same zone and there is not busy superior orbits.
The slightest electric field is going to assure the electronic excitement and the relocation of orbits in the network will engender a collective behavior: the electric current.
In the intermediate case of semiconductors, the conductivity increases
with the temperature and the impurities, the drugs, modify strongly the
conductivity because the very orderly environment can easily be perturbed.
5 A stable nucleus
In first approach, 2 types of particles constitute the nucleus: protons and neutrons grouped under the term nucleons. These two particles are also subjected to the laws of exclusion from Pauli; no particle of the nucleus is in the same quantum state there. There is thus a notion of level pile of energy as for electrons even if the notion of layer with an average physical distance in a centre of attraction loses its sense in the nucleus which is rather seen as a region where particles become entangled.
It is the electrons which determine the chemical properties of a component. The number of protons being equal, it turns out that the chemical properties do not depend on the number of neutrons. We thus have isotopes, that is number limited by body possessing the same number of protons and a variable number of neutrons.
The nuclear forces assure the cohesion of protons and neutrons. They surmount the forces of aversion between protons. They are in very short reach; as the experience of Rutherfort indicates it, the nucleus is very small.
The observation of nucleus mirror, that is alternating their number of protons and neutrons as He3 And H3 allows to conclude that the strong force acts in the same way on the neutrons and the protons.
The character of force with short reach acting only between close neighbours differs sharply from the electric aversion which is smelt in all the nucleus.
As regards the electric force, the aversion increases with the number of protons. While a proton is attracted by the strong force by an about constant number of neighbours, protons or neutrons, it is repelled by an increasing number of protons.
The neutrons not being affected by the electric force but contributing to the attraction by the strong force, the heavy nucleus possess a surplus of neutrons with regard to protons to stabilize them. The limit is the phenomenon of natural radioactivity which provokes a split of the nucleus. The competition enters the energy of surface (the strong attraction enters nucleons) and the electric aversion should lead to unstable nucleus around 125 protons. In fact to imagine the nucleus as a bag of ball is profoundly false; corpuscles being localized, as waves, there are transitions, evasions, which occur before the threshold is reached. In fact all the nucleus with approximately 90 protons are already unstable.
Another way of seeing it is to say that the particles which have an insufficient kinetic energy to cross the barrier constituted by the surface energy borrow their energies for short moment. This effect is authorized by the relations of Heisenberg, let us remind ourselves that the energy is indistinct if the moment of time is precise. Or the block of escaped particles restores this energy to their environment but after their evasion. The radioactive split (with liberation of photons with high energy) can thus occur earlier than a simple classic calculation authorizes it.
By measuring exactly the individual mass of protons and neutrons (what includes for the proton the mass of its electric field) and the mass of these particles collected in a nucleus, we observe a deficit of this grouped mass, deficit which is interpreted as an energy of connection (in other words of mass of the vector particles of the strong forces in the nucleus, the force which appears specifically in the nucleus).
The light nucleus are weakly connected because of the reduced number of neighbours. The heavy nucleus are less tight than those of intermediate mass because of the increasing electric aversion. The light nucleus produced by fusion or the heavy nucleus produced by fission produce nucleus more strongly tight than their parents and thus release energy.
The fission and the fusion become ineffective in the intermediate region of the iron, there where stop the stable processes of fusion in the most massive stars at the end of life.
How a nucleus assure its stability?
It is about a balance between protons and neutrons. Subjected to the laws of exclusion from Pauli, as soon as a level of energy is filled, the other nucleons has to squeeze on superior levels. There are two different piles for protons and neutrons.
It always tends to it in a system to minimize its internal energy for a given level of organization. When the pile of the neutrons is higher than that of protons, the nucleus tends in continues a neutron which splits in proton by producing a compensatory electron. The atom thus gains a notch in the list of the chemical elements.
The law of exclusion has for consequence that the pairs neutrons-neutrons and proton-proton repel whereas the couples protons-neutrons incur by the strong force where from a comparable number of protons and neutrons at least for the light elements where the force of electric aversion is little important.
But in the heavy nucleus the high force of electric aversion raises the lowest level of necessary energy to compensate for it. So that the summits of both piles are for the same level is needed an excess of neutrons with regard to protons.
All the problem is the excess of neutrons to dilute the influence of the electric aversion and the balance proton-neutron to benefit from their attraction there that they are two in two subjected in the law of exclusion.
If there isoo many neutrons, the nucleus undergo a destruction of their neutron, not enough and they are unstable. To get back to their stability, protons absorb the close electrons, attracted notably by the heavy nucleus, to form a supplementary neutron by losing a notch on the list of elements. Let us forget by the uncertainty on the position of the electrons which authorizes this fusion. This process requires some energy which comes from the energy of connection because the earning compensates for the decrease of the energy of connection. It is not thus spontaneous otherwise all the free protons forming the hydrogen of stars would have been converted in sterile neutrons.
We shall not here try to describe the physics in the work in the coupling of the particles of the nucleus. Let us clarify simply that the strong force is much more complex than the electric force because it exercises between nucleons mixed without notion of central force and it depends not only on the distance but also on the relative orientation of their spin.
It is interesting to notice that the force of gravitational attraction
described in the general relativity depends not only the distance but also
the tangential speed to the attracting body..
6 Scale of stability and scales of the forces
Because of the ratios of intensity between the forces:
- The strong force acts only in the atomic nucleus (dimension of Fermi = 10-15 M) Because it has a reach of 2 Fermi slightly lower than the size of the nucleus indicating that she acts directly between 2 nucleons close relations (neutron or proton).
- The weak force acts in all the exchanges of identity of particles and its reach is limited to 0,01 Fermi (10-17 M)
- The electric force acts of 10-15 M in 10-8 M (some hundreds of Angström). Beyond the orientations of fields nullify. The exception is the phenomena of large-scale plasma (lightning, ionosphere, stars, stellar and intergalactic plasma). Nevertheless the global environment is constituted by neutral matter and the electrons of the electric atoms exercise their effect of aversion and thus pressure on all the surfaces in contact of the solid bodies (or between molecules for the liquid and gas bodies).
Beyond 100 000 km, bodies are so massive that the heat loosened by their contraction ionizes them again; the electric force acts directly
- The force of gravitation is cumulative. Bodies from 0,1 m feel the global effect of the gravitation and this effect believes with the mass as the effect of pressure by contact bound(connected) to the electric interactions becomes unimportant.
We thus distinguish 7 in 8 zones
Below 10-17 M, the weak force is dominating. It acts only during the transmutations of particles during spontaneous destruction or in a link provoked by a high kinetic energy of particles sources.
Between 10-16 And 2*10-15 M, the strong force is dominating. It assures the seclusion of nucleons forming the atomic nucleus which possess a characteristic size of 10-13 M
Between 10-14 And 10-8 M, the electromagnetic interaction acts in a direct way but
Between 10-14 And 10-9 M, the electromagnetic field allows the constitution of stationary waves (which are baptized electrons in an atom); the attraction of the nucleus is so neutralized.
Bodies between 10-8 M and 105 Km is statistically neutral and the electromagnetic interaction acts step by step by the effects of pressure and superficial tension there.
The effect of pressure increases in opposition with the influence of the gravitation but becomes sensitive only for the bodies of beyond 0,1m.
The zone enters the border of fast waste of the structures by electromagnetic disturbance (less than 107 M) And the border beyond which the pressures compensating for the weight are too much raised for large structures (some dozens metres) is the zone of the alive.
Between 105 Km and 109 Km, the electromagnetic interaction acts in plasmas and engenders the pressure of radiation by the engendered collisions.
Even there the electromagnetic effects oppose to the gravitation but in that case the opposition is between a centripetal interaction and an effect of stochastic distribution.
Between 109 Km and at least 1024 Km (size of the observable Universe), only the gravitational interaction acts.
It is finally necessary to us to note two particular zones.
The first one is the zone between 104 And 105 Km for the massive bodies of the order of the mass of the Sun. That is a zone of balance between he gravitation and repulsion between electrons owed to a phenomenon of destructive interferences of the electronic waves: electrons occupy limp with minimal dimension. It is the zone of the brown and white dwarfs whose matter is degenerate because its stability is due to the law of exclusion from Pauli.
Let us note finally the particular zone around 10 km for bodies also of the order of the mass of the Sun corresponding to the centre imploded of one Supernovae and subjected, for the central part of the resultant celestial body, to the law of exclusion from Pauli for the neutrons (the fast electrons merged with protons).
The forces of the Nature Paul Davies Champs Flammarion
The quantum object Simon Diner Champs Flammarion