The cosmic origin of Life
The cosmic origin of Life is a question in the confluence of the great scientific domains. In a way it requires almost all the Science because it requires to answer three fundamental questions: where from comes the World, how the Universe has been able to get organized to create Earth as a shelter and what is Life. Additionally it is possible to answer questions such as how the life can remain on Earth, evolve, until the Man and what Man can do to spoil everything...
In this trip, we shall describe the origin of elements, the forming of the solar system, the Earth and the Life, which are its main forms and which are tracks in the research for the transition from inanimate to animate life. In a court to summarize we shall describe the evolution up to the Man.
The subject of the fragility of equilibrium conditions on Earth, of the importance of hazard in the elaboration of the alive and the influence of the solar system on this evolution opens then.
The question of the anthropological principle, that is this often hostile universe is then approached, an universe which, strangely, seems to create to assure at least the appearance of the life: on what bases this principle and what this principle can bring as a guide for more knowledge?
It seemed then natural to end by the synthetic and global reconstruction,in
the course of time and in all the scales. This reconstruction tries to
show the particular conditions which allowed the majestic and hierarchical
construction of Life, so splendidly complex, sensitive and precious.
1 The origin of the solar system or how to form an Earth, source of life? *
1.1 The synthesis of elements *
1.2 The chemistry of clouds *
1.3 The second generation of stars *
1.4 Forming of the Solar system *
1.4.2 The disc of accretion*
1.4.3 Forming of planetoids*
1.4.4 Accretion of the Earth *
1.4.5 Forming of the oceans and the atmosphere*
2.1 The apparition of the life *
2.2 Characteristics of the life *
2.3 In search of our ancestor
2.3.1 Some principles
2.3.2 Of which are we made ?
2.3.3 Table of caracteristics
2.4 Evolution of the genetic message *
2.5 Research ways *
2.6 The epic of the life *
2.5 The explosion of the Cambrian *
2.6 The choice*
3 An ecosystem in interaction: impact on the evolution *
3.1 The Sun-Ocean-Atmospher balance *
3.2 The chaos and the life *
3.3 The new departures of the life: sun - Asteroids - Jupiter*
4 The origin of the previous history*
5 The Big-How: the question of the anthropocentrism*
5.1 The Question *
5.2 Why the World is such as it is? *
5.3 The chain which allowed the life *
5.3.2 The Chain of the evolution *
5.3.3 Of the Moon in the Cosmos, the Whole and (almost) nothing*
The origin of the solar system or how to form an Earth, source of life?
It is necessary us to understand how the stellar and interstellar evolution by making the synthesis of all the chemical elements was going to open the possibility of the organic chemistry and to lead to the hatching of the life.
A star balances its pressure of radiation with the weight of the layers of outside gases. When the brilliance decreases for lack of fuel, the heart of the star compresses, the temperature rises until the ignition by fusion of another fuel.
The balance characterizes the biggest part of the life of the star what assures a still brilliance.
The mass of the star is the factor which determines very widely its speed of evolution, as well as the depth in the table of Mendeleïev of its nuclear genesis.
A star 10 times as massive as the Sun is 1000 times as brilliant and evolves 100 times as fast: it will disappear in 100 million years.
The diagram was established by Hertzsprung and Russel, a Danish and a American astronomers, indicates the luminosities of stars according to their superficial temperature .
As long as they transform the hydrogen into helium, stars are situated on the main sequence. They fork then in the successive synthesis of new elements by contraction which heats the heart and dilates the peripheral layers to transform the star in red giant.
The main contribution to the synthesis of the chemical elements is that of the most massive stars (30 sun masses and beyond).
At first a cloud from 10 to 100 000 sun masses splits up identically in all the scales, forming nebular nodules. The birth of stars begins with the collapse of these nodules.
In the center of every fragment, a protostar forms around which revolves a wide whirlwind of gas, pulling with him a wide fraction of angular moment.
Let us consider the situation of one of these massive stars.
The whirlwind ends in a disc of accretion which falls on the protostar and supplies it 30 sun masses with a dozen million years.
This star of first generation is essentially constituted of hydrogen and helium, the synthesis of metals not being begun.
The central star compresses and a plasma separating the nucleus of hydrogen and helium of their electrons forms in 50 000 K. When the centre reaches 40 millions of K, the nucleus of hydrogen (protons) acquired a speed high enough to overcome the barrier of aversion electrostatics. By getting closer at a distance equivalent in their visible diameter, they are subjected to the attractive nuclear force. This force is in very weak reach because it is carried by bearers of load with brief existence. This force welds the pair of protons which is transformed into a couple proton-neutron, by expelling an anti-electron, which lives in the plasma until annihilation with an electron, and a neutrino which crosses all the stellar mass because it interacts only too weakly with the other particles.
The deuterium so shape goes meeting another proton forming helium 3. The meeting of 2 pits of helium ends in the stable helium 4.
In the term of 60 million years, the heart consumed all its fuel. The star collapses in search of a new balance. The temperature of ignition of the helium is reached to allow the simultaneous fusion of 3 nucleus of helium to form some carbon. The slow contraction of the core makes him reach 400 millions of K and the heating of the intermediate layers in 40 millions of K provokes the starting up of the fusion of the hydrogen around the core: the structure in layer of onions is set up.
The outside layers swell by pressure of radiation and the diameter of the star is multiply by 100.
The fusion of the carbon and the helium towards 400 in 500 millions of K engenders the oxygen. The neon and the magnesium appear towards 600 millions of K.
But the principle of exclusion from Pauli between electrons, which prevent them from taking the same quantum state as an already occupied state blocks their compression: the temperature cannot fit any more and the fusion of the carbon becomes explosive; the main elements up to the iron are quickly produced. The star produced 7 elements which constitute 99,9 % of the matter in the universe.
But the last synthesis is destructive. Indeed the energy of photons allows them to destroy the iron nucleuswhich have been synthetize and split them into nucleus of helium. The reaction consumes some energy and the star collapses but the impossibility of the compression of the heart provokes the bounce of the external layers on the core: the star explodes in supernovae. The fusion of the electrons of the plasma with protons produces a wave of neutron which accompany the shock wave. Protons and propelled neutrons go by fusion with the already formed elements generate all other elements of the table of Mendeleïev . In the case of a fast arrest of neutrons, nucleus arrest some simultaneously what allows them to jump directly towards another stable nucleus. In the case of a slow stop, nucleus have the time by beta desintegration to fall again towards a simpler stable element.
As for the stops of protons, they fill the gaps of the elements which were not forms besides .
But the only energy of the
shock wave is insufficient to explain the eviction in the space of the
major part of the star. Neutrinos are emitted during the forming of the
neutrons during the absorption of electrons by protons. by their density
and by an effect of second breath, the neutrinos pull the explosive wave
in the space.
More the mass of the star is more brought up the report oxygenates / carbon increases.. During the ejection of these elements by the interstellar wind or by the phenomenon of novae or supernovae, the gas cools forming the carbon monoxide very stable (CO). The bubble of gas will keep in excess of the carbon or the oxygen; it will be reducing or oxidizing.
Composition of clouds: 70 % H, 28 % He, 0,3 % of CO, 0,7 of O, 0,2 N,
0,1 Fe, 0,05 % Mg and 0,5 Yes.
0,2 % of oxygen oxidizes metals and the staying 0,5 % form some steam.
The falling temperature, the oxides form silicates especially of iron and magnesium. Then silicates condense in ultratiny grain(bead) of 0,1 microns.
In the clouds of molecular gas the temperature is excessively low and atoms freeze on the surface of the grains which recover of a film of hoarfrost and reach a size of 0,3 microns.
The concentration of dusts within clouds blocks the diffusion of the stellar radiations, the temperature of these clouds fell more still and the mass required to overcome the pressure of radiation fell; clouds collapsed and formed intermediate or weak stars of mass, as our Sun. Dusts were partially absorbed by the rising stars, another part formed their procession of comets and planetary systems. The immense majority of dusts nevertheless escape to form less dense clouds and thus more subjected to the ultraviolet brilliance of the massive stars. The coat of hoarfrost was dissolved leaving a coat of organic matter on the heart of silicates. The molecules of water, methane and ammonia release free radicals who re-harmonize in organic molecules. The coat of organic molecules protect the grains of silicates of the effect of the shock waves of supernovae until grains meet themselves again in dense clouds to pursue the cycle. But rather quickly the contents in dusts are reduced because of the decrease of the number of massive stars what reduces in return their forming. The phase of fit of galactic stars seems to go back up 5 to 10 billion years behind with a peak here is 7 billion years. Typically the Milky Way do not form any more today than some stars a year.
Stars of masses lower than 20 Mb loosen more carbon than oxygen in the gas bubbles resulting from their explosion in supernovae. As a consequence, the expanding reducing bubble will contain especially of the CO followed by CN and HC. And the first triatomic molecule will not be any more H2O butHCN (cyanhydric acid) grains of metal iron will condense in the side of grains of graphite and diamond. Grains are covered with a hoarfrost of hydrocarbon including compose organic.
The absorption of the light in the various wavelengths (especially of the visible in the ultraviolet ray) allows to find the proportion and the type of 3 types of dusts: dusts frosted in heart of 0,3 micron silicates, the grains of amorphous carbon of 0,1 microns and the chains of aromatic hydrocarbons of 0,02 microns.
The enormous bubbles are going to continue to form throughout the 10 billion years preceding the creation of our System. The multiplicity of the stars of masses reduced contributes to the process of forming of the global nebulas (external layer escaping by the turbulences of the stellar wind of a red giant in the distended atmosphere). The millions of bubbles cover all the range of the strongly reducing in the strongly oxidizing. They are going to interpenetrate in the interstellar clouds accumulating along the galactic arms where the waves of density provoke the condensation of the stars of big masses. Clouds form 10 % of the galactic mass and possess dimensions from 10 to 100 Y.-L ., their density ranging from some particles to millions of particles by cm3.
In the dense clouds we have identify some 80 sorts of different molecules by their spectre of emission,. Among them, 60 are organic.
The density remaining very weak, the collisions are rare and molecules have to form on the surface of the solid grainswhich have a double function of substratum and contribution of catalyst.
The source energy is the ultraviolet brilliance of the stars which ionizes the helium. This helium strikes molecules and provokes a waterfall of ionization.
It remains to note that all the molecules meadow bioticks in particular
H20, a H2CO ( FORMALDEHYDE ) and
HCN are present abundantly everywhere in the Galaxy.
The sowing of the interstellar environment by the carbon allows the following generations of stars to accelerate the processes of fusion of the hydrogen by a phenomenon of catalysis.
The massive stars consume their fuels from 10 in 15 millions of K and do not need to achieve the 40 millions of K of the first generation.
The cycle of catalysis is established ( by a carbon which absorbs a
proton forming the nitrogen 13 which splits in carbon 13. This one passes
in the nitrogen 14 by a new absorption. The nitrogen 14 absorbs another
another proton to form the oxygen which splits in nitrogen 15. By a last
absorption this one splits in a nucleous of carbon and in a nucleous of
1.1.4 Origin of organic matters
The primitive meteorites say chondrites possess the same ratio of abundance between the not volatile elements (said "metals") as the Sun. The volatile elements are absent only in meteorites formed in too warm regions to retain them.
This chondrites is compose of agglomerated grains, sedimented in cold and which are not in chemical balance: the totally oxidized is next to the totally reduced, the fireproof igoes alongside to the volatile and alters it by the water be next to the anhydride.
The origin of grains is multiple because several stars have contribute to their synthesis but their sedimentations results from the separation of gases and from some dusts during the stopof the collapse of the interstellar cloud on the protosolar disc . This separation stops the turbulences and blocks finally the sedimentation.
411 compose organic were identify for example in the carbon chondrite of 1969 found to Murchison , Australia.
Among 74 amino acids find, 8 are use in proteins. All the found purines is use as codeuses letters in the DNA transcriber and ARN messenger of the alive.
Also the analysis by real-time spectroscopy of dusts collected during the passage in the tail of the comet of Halley allowed to identify isotopic abnormalities and led to suppose 4 different stellar previous history for these comet dusts.
In the Sun the report C/O is 1 for 3, this report is scrap by the analysis of the carbon meteorites and generally oxidized but containing a strong proportion of grains of metal iron and thus reduced. This abundance is the same in the comet of Halley.
The Solar system summarizes it was shape here is 4,5 billion years from a molecular cloud place in a spiral arm enriched of multiple compose organic (containing C, N, O, S) produced by the numerous stars of the first generations. These dusts were essentially constituted by silicates covered with a film of hoarfrost of water but also with the hoarfrost of compose organic volatile.
Within this huge molecular cloud, the present lumps have all the sizes
revealing an invariant process of scale. Bit by bit the most massive lumps
collapse and form stars from 50 to 60 sun Masses. At the end of some million
years, they explode in supernovae. The warm and oxidizing bubbles propagate
in the form of a shock wave and provoke the collapse of hundreds of less
massive lumps of which a nodule about 1 sun mass: our Sun and its future
1.4.2 The disc of accretion
The module collapses but the conservation of angular moment maintains and strengthens the turbulences within it and only 5 in 10 % of the mass takes a spherical shape, the rest flattens in a wide disc. By friction, the matter of the internal zones is slowed down and falls towards the heart what feeds the Sun and brings it all its mass
The matter of the outside zones is accelerated and widens rings by taking the angular moment.
100 000 years are sell since the beginning of the collapse.
The nebular nodule ends its collapse, the turbulence decreases and dusts
become sediments. The not differentiated coming
chondrites small asteroids testify of this mixture. The separation
between the gas and the dusts takes only some thousand years. This can
be taken by agreement as the zero moment of the solar, pressing System
which the radioactive age of chondrites
makes go back up to 4,56 billion years.
1.4.3 Planetoids forming
Dusts turn on orbit around the central nodule but are attracted by the disc and fall perpendicularly. Their oscillation is quickly paid off by the turbulence.
The residual turbulence slows down the aggregation of dusts but less than 100 000 years are necessary for the apparition of object from 1 to 10 kilometres which are going to turn in gigantic rings around the Sun The substance ofplanetoids change with the estrangement the Sun but in the zone of the ground planets the temperature is of the order of 1000 K; the particles of silicates are totally dehydrated and the volatile are degased.
But from a distance of 5,2 A.-U.. (Outstrip Sun Jupiter) the superficial hoarfrost does not vaporize any more in spite of the rarity of the gas which surrounds grains. Planetoids contains big quantities of snow of water: they are the pits of the primitive comets.
During this time the protoSun is 5 times as brilliant that today because in spite of a weaker superficial temperature (4000 K instead of 5800K) its surface is 20 times as big.
Its too much raised speed of rotation makes for it eject an equatorial gas ring which collides the disc of accretion , mechanism by which the growth of the Sun is stopped. The gas is bent by the magnetic field of the star and escapes by the poles (objects of Herbig-Haro). The shock wave with the disc of accretion blows completely the gas residues and the fine dusts of the disc in 2 in 3 million years.
Only is saved the planetoids of more than 1016 Kg having already undergone an accretion before this wind said about "T-Tauri" (according to the first star of this type identified).
Uncountable collisions of planetoids which turn in the same sense on close orbits end in a distribution of mass which is again invariant in all the scale.
In the final stage, the attraction of objects not being unimportant any more, the growth of the massive objects is carried away whereas the smallest objects undergo more violent collisions and split up.
Beyond the zone of the disc in 450 K (zone of the ground planets), silicates and the iron grains which form 0,3 % of the mass of the gas.
On the other hand to 5,2 U.A. (the distance of Jupiter) the ice of water weighs down grains and the solid phase constitutes 1,8 % of the mass of the gas. Besides the volatile elements, evaporated grains diffuse of the internal zone towards the outside and condense on the cold wall to 5,2 U.A.
Instead of a heart of 1 ground mass, the heart of Jupiter is from approximately 10 ground masses. Besides the planetoids of the zone (they are comets) is quite absorbed as was it in 1994 that of Schoemaker-Levy and the core of Jupiter is by way of 29 ground masses. It allows it to accumulate quickly some 300 masses amount ground of gas which surrounds it.
Jupiter by its attraction is going to eject a wide part of planetoids frozen except the Solar system.
A fraction will substitute in the sphere of Oort of a diameter superior to 1 A.-L .
Some millions (what is a very reduced fraction) stabilize in the belt of Kuiper by echo with Neptune.
A big number of these comets perturbs the belt asteroids during their ejection: the collisions between asteroids will be made in bigger speed preventing the forming of a planet and perturbing strongly the growth of March (this one is only 10 % of the Earth).
They are also going to bombard the Earth, to destroy its primitive atmosphere and to delay the stabilization of its climate.
4 telluric planets result from the collision of about twenty objects of the size of March. The eccentricity of the orbit of these objects being modifies by Jupiter which favors their collision.
Bitter 40 million years, the Earth is formed, its compose volatile evaporate because of the collisions.
Only remain 2 or 3 objects of the Size of March on unstable orbits. The one went collide with Mercury to make it lose its crust silicate.
Other one was going to collide the Earth to form the Moon. The time
found by the radioactivity of the lunar cliffs is 130 million years after
the sedimentation of dusts.
1.4.4 Accretion of the Earth
The kinetic energy loosened during an impact believes with the square of the speed, the speed being proportional in the radius of the attractive object . The energy and the temperature thus grow with the square of the radius: the surface warms the inside. Bit by bit, the centre of the Earth liquefies: the iron, already reduced under metal shape in the space, forms a central core on which silicates float. The radioactivity of the uranium, produced by supernovae, is going to maintain this heat.
The ground mass has three essential effects:
The rate of enrichment of the deuterium is the report of the rate of deuterium between the molecules of water and molecular hydrogen where in both cases the hydrogen is replaced by its isotope deuterium. We so estimate the report HDO / HD.
Now the oceans and in the radicals O-H of cliffs include each approximately 50 % of the hydrogen and the average rate of enrichment of the deuterium of these 2 sets corresponds to the average enrichment of the meteorites of type carbon chondrites. Let us remind that these are formed by chondres, that is by assembly of hydroxyles silicates gathered in weightlessness in more than 1600 K and cooled in some minutes in the form of droplets. Their not volatile constituents are representative of the composition of the nebula protosun.
In fact the rate of enrichment for these meteorites varies from 3 to 30 with an average of 6.
The rate of enrichment between the deuterium and the hydrogen amounts with the distance to the Sun and this rate is 12 thus twice as importing in the comets that in the average on Earth (and in the sea).
But there is no unity of sight on this point because if we consider only the rate of deuterium of the oceans, it gets closer to the rate of forming in the zone of accretion of the comets in the region of Jupiter. It corresponds to the rate obtained by condensation of the water in 200 K. The molecule of water under its 2 isotopes H2 O and HDO condenses in the form of snow which can then cool in lower temperature. This indicates how the snow of comets condensed and ends in a comet origin for the oceans.
It is sometimes advanced that the oceans would be formed in ¾ of water resulting from chondrites, the remaining quarter having been brought by comets. Now the bombardment by asteroids becomes unimportant statistically after 200 million years unlike the comet bombardment which continues and evacuates in the space the atmosphere of the previous history overheated and saturated by steam, before the first oceans condense.
Under this hypothesis, the bombardments which would have allowed the constitution of the current oceans would have essentially been the fact of comets from 5 to 500 km coming from the zone of the huge planets and the orbit of which had been perturbed by their growths. They would have brought us 10 times more water than it stays there and 1000 times more gases than it does not live there today. This phenomenon seems to supply the quantity of carbon noticed today.
In fact the comet bombardment continues under the shape of 1 micron dusts coming from the zodiacal light. We consider at 1018 Tons the quantity of organic matter deposited by comets and their dusts since the beginning of the Earth.
Besides, the distribution of the isotopes of inertial gases (or noble gases) in the atmosphere such as the xenon or the krypton is incompatible with their membership with a primitive atmosphere; they were brought by a source which separated them before the arrival on Earth. Clathrates (present hydrates of water in comets) was able to play the role of chamber of stocking and separator with cold of the various isotopes. The bombardment would have had the effect of provoking the disappearance of the volatile materials and would explain the quantity of materials close to some iron present in the earth's crust.
But the problem is not so simple, even if the theory seems attractive, because the geologists support the thesis of the internal origin of the oceans because of the considerable degassing of the coat in high temperature during the forming of the Earth.
A third very serious hypothesis, the micrometeor origin, comes from the antartic ice sampling.
We estimate from fifty to hundred tons the quantity of meteors which falls every day by the Earth. Approximately 99 % of this mass is brought by micrometeorites the diameter of which included between 50 and 500 µm. These micrometeorites are similar to the most primitive meteorites, those of the group of the carbon chondrites. An analysis detailed by the contents in carbon of various groups of micrometeorites allows to consider at hundred tons a year the total stream of carbon brought to the Earth. The quantity delivered to the Earth during the active phase of the Earth bombardment between 4,1 and 3,8 billion years, when the stream micrmeteors was credibly one thousand times more intense than today, is estimated at 30 000 billion tons. As comparison, this value represents thirty times the current value of the recyclable biologic carbon to the surface of the Earth.
Amino acids were discovered in micrometeorites. These grains contain a strong proportion of metal sulphides, oxides, clays which are so many catalysts. In the contact of the liquid water, grains were thus able to work as chemical micro-reactors transforming the organic matter of grains by means of the present catalysts.
The micrometeorites of size lower than 5 m should not assure any more an effective protection against the sun UV radiation.
According to the concentrations in carbon and the isotopic compositions
some oxygen and some hydrogen in micrometeorites, isotopic composition
(report D/H) some water of constitution of silicates hydrated by micrometeorites
presents a surprising similarity with the mean value measured for the ground
oceans. Concerning the neon, it is considered as a very good tracer of
the origin of the atmosphere.
Micrometeorites are among objects the most enriched in neon. This composition is thus similar to that postulated for the primitive atmosphere of the Earth, tracks of which we find in the cliffs of the superior coat.
These isotopic resemblances, observed for the water and the neon, micrometeorites suggest that they contributed to the forming of the ground water, indispensable to the appearance of the life, and the primitive atmosphere of our planet.
A model of accretion of primitive micrometeorites would allow to report
some heterogeneous mixture of neon, nitrogen, carbonates and water observed
on Earth nowadays, the quantities of which differ nevertheless from a factor
of 100 millions in the case of the water and from some neon.
The very simple and very general process of accretion of micrometeorites " carbon hydrated " would bring to him only all the ingredients necessary for the appearance of the life: some water, complex organic molecules and a big variety of catalysts. As this accretion is one under "common" product of the forming of planets, the probability of life in the universe would be higher.
Enclosed the table of the compositions
|Atmosphere||Solar Nebula||Haïwai Volcanoes||Wisps of smoke||Ice||Dust|
|CO2/N2||90||0,1 à 1||4||6,6||5||30|
|H20||10 à 28||270||350|
|CO2||4,6 à 12,5||120||90|
Quantity (unity grams)
|N2||4 1021||5 1021|
Today the only definitive conclusion which we establish by the models of the proto sun nebula is that the water cannot result directly from the oxidation of the essential hydrogen. Indeed the molecule of water is formed by oxidation of the hydrogen in 1200 K there and molecule HD (hydrogen - deuterium) is gradually transferred into triatomic molecules HDO. By modelling the cooling of the nebula, the rate of enrichment of the deuterium in the water with regard to the diatomic hydrogen remains in every case insufficient because it is only a factor 2.
A realistic model would suppose an initial enrichment in deuterium of the nebula proto solar energy close to the maximal value found in chondrites and, after evaporation of the interstellar ices, then the rebalancing of isotopes with the hydrogen and new condensation at the end of a million years of cooling with a nearby rate of 3. There would be indeed combination of the contribution of meteorites and comets, partially member of a minority party, to find the ground rate.
The radio astronomers were able to identify 83 different organic molecules built from carbon and from hydrogen.
Meteors and comets were able to bring a big quantity on Earth.
Approximately 80 % of the grains of comet origin contain some organic matter and did not melt in the atmosphere. What corresponds to 100 times the quantity of carbon at present recycled by the biomass.
Besides all the amino acids further one sense of rotation; they are direct to the left.
This peculiarity was observed only on Earth.
Now the explanation at present advanced is connected to the polarity of the stellar radiations which would have destroyed the right forms.
Here is 4 billion years, the Moon was 6 times as close at least as today and the tides were 30 times as strong. The duration of day was of a dozen hours.
The atmosphere was near 60 times as dense and the sun less brilliant 30 %.
Our atmosphere has 3 sources among which the respective parts vary according to the authors:
- the degassing of the ground coat
It seems to get free that a wide fraction of the atmosphere results from the degassing of the ground coat, degassing which continues in a way reduced by the volcanic fireplaces found in Galápagos and in the East Pacific.
This degassing from volcanoes would have, if the ground coat was very reducing, ejected an important proportion of methane which, scattered in the high atmosphere in the form of organic sprayers, would have protected a weak fraction of ammonia (1/100 000 in an atmosphere of 1 bar). This ammonia would have contributes to the elaboration of the chemistry meadow biotick and the forming of amino acids. Ingredients would have probably been supplied by comets or by hydrothermic chimneys of the oceanic bottom.
The problem is that the current models do not envisage a primitive coat rather reducing to produce the good quantity of methane.
In a second time a much more oxidizing atmosphere on base of CO2 from 1 to 10 bars would have is enough to maintain the Earth under greenhouse effect. This greenhouse effect was indispensable because the Sun was then less brilliant 30 % that today and without him the Earth would have known only Siberian colds .
The CO2 would have slowly declined at the same time as the gliding of the Sun on the main sequence and as the increase of its superficial temperature.
The volcanism is indispensable to the continual recycling of the carbon because without him the carbon dioxide would have precipitated in only 400 000 years and the greenhouse effect would have disappeared.
Other fraction of the atmosphere thus comes from comets and asteroids.
80 % of the mass of comets is constituted by a volatile part which thus enriched our atmosphere. The steam condensed in oceans as soon as the Earth is crossed under its boiling point (230°C under 30 atmospheres) .
In the remaining fraction of comets, we find of the formaldehyde which would have polymerized thanks to sun and formed ultraviolet rays a solid mist of particles in the stratosphere. The ammonia is separated in nitrogen and in hydrogen, this one escapes because in these temperatures, its speed of excitement is very superior at the speed of ground liberation.
The temperature falls to 100° Celsius .
The composition of the atmosphere: 80 % of CO2, 10 % of methane, 5 % of carbon monoxide and 5 % of nitrogen N2.
Rains acidified by the CO2 attack silicates. The formed carbonates constitute solid sediments which bury the CO2. The pressure falls in 5 bars.
The ground atmosphere stayed at first in an intermediate state of oxydo reduction during first 500 million years, thanks to the continual contribution of the gas of comets.
The CO2, present initially in great quantities, and N2, whose contribution is more reduced, stood out as the major constituents. The CO2 disappeared in calcareous rocks (which to them only contain the equivalent of 20 atmospheres) and the nitrogen, sluggish geochemical, accumulated during time and constitutes the major part of an atmosphere in the reduced pressure today.
Reducing gases are photo separated under ultraviolet rays sun or oxidized by the small quantity of oxygen released by the photodissociation of the water. Bit by bit the atmosphere is going to grow rich in oxygen thanks to the photosynthesis of cyanobacteria (the first 5 %), then by algae (approximately 12 %), and finally by plants (4 %) to reach 21 % of the atmospheric partial pressure.
The main comets impacts come along with the boiling of the oceans and lead to fantastic ejection of water and gas towards the space. Terrible hurricanes burst out and disrupt violently all the earth's surface. These phenomena are strongly reduced here is 3,5 billion years.
But the life in so terrible conditions already teem under a cellular
shape in the warm water of the first oceans.
2 The life: sources and progresses
2.1 The apparition of the life
All the forms of ground life have a common origin. They possess all the same proportions of atoms: 62 % of hydrogen, 27 % of oxygen, 8 % of carbon, 2 % of nitrogen, 1 for one thousand phosphors, 1 for one thousand of suffers, iron tracks for the blood of animals, calcium for the bones of vertebrates and the tracks of magnesium for the chlorophyll.
Atoms are collected in molecules.
All the forms of life consist of 80 % of water, reminder of the aquatic origin.
Other molecules are 20 amino acids connected in long chains: proteins.
Only the organization of amino acids in proteins differentiate them.
Proteins distinguish themselves in 2 groups: the structural which constitute the organisms and the enzymes which choose and direct the chemical reactions.
The assembly of amino acids to constitute proteins follows the codification imposed by the links of the nucléique acid (DNA and RNA). This nucléique acid is formed by molecules different from amino acids: it is about 4 molecules: 2 purines and of pyrimidines 2. Both are only particular combinations of hydrogen, oxygen, carbon and nitrogen.
Between the DNA source of the coding of proteins and RNA support for their constitution there is only a single variation in these 4 molecules
The life is thus based on 30 molecules: 20 amino acids, more purines and pyrimidines being of use to the nucleus coding, and the less fundamental molecules for the apparition of the alive (phosphate, sugar and lipids).
Now all these molecules necessary for the life can be produced from water, from ammonia NH3 or from cyanhydrique acid HCN for the nitrogen, by methane CH4 or byformaldehyde H2CO for the carbon.
The synthesis of these elementary bricks in the molecules of the life seem impossible on Earth because the atmosphere was not reducing unlike what supposed initially Urey and Miller.
But all these basic molecules are present in the molecular clouds where a slow synthesis with low temperature occurs. What were thus vectors towards the Earth?
These elements are present in the carbon chondrites protected from the fusion by their superficial layers.
They were also discovered in comets hair. The contribution of the bricks of the life date the diverse accrétion at the first ages of the Earth.
It seems that meteors bombardments here is 4 billion years forced the earth's crust in the melting point by destroying periodically any attempt of development of the life. This one was finally able to stabilize only after the end of the massive bombardment here is 3,8 billion years.
The deposit of dusts falling again comets impacts in bubbles of foam on the surface of the oceans forms the first possible support for the forming of the first cellular walls.
Another possibility is the deposit of dusts in clayey capital containing
grains of montmorillonite favorable
as first site. These deposits would have formed in lagoons or in big lakes
undergoing the phenomenon of tides.
|Bacteria||Mammals||Interstellar hoarfrost||Volatile fraction of comets|
The life looks like less the Earth (silicate of cliffs) than in the interstellar matter.
The calcium is only necessary for animals (shells, skeletons).
The phosphor was concentrate in the first cells probably because phosphates
have bring some energy before the invention of the photosynthesis by the
Characteristics of the life
A body is alive if he can reproduce and evolve.
The structure which allows to stabilize the series of necessary reaction is the cell; the base of the alive.
Its confinment with regard to the outside environment is assured by a semipermeable membrane which filters molecules in entry and in release and preservation the environment interns in a still state but far from the thermochimical balance.
Its stability is assured by negative feedback which bring it a partial autonomy of the environment.
Substances are brought from the outside (food), the energy is brought
by the metabolism and transformed into heat and into action, the not useful
products of the reactions are evacuated.
2.3 In search of our ancestor
2.3.1 Some principles
The unity of the contemporary living and its mode of cellular functioning
suggest that the life appeared under the features of a simplified cell.
During decades, the chemists made every effort to reconstitute in laboratory molecules indispensable to the functioning of a contemporary cell: the molecules of compartment, the molecules of the assembling plan and the catalytic molecules.
Membranes assure the cohesion of the cell. They are formed by amphiphiles
molecules which possess at the same moment a hydrophilic polar head and
carbon hydrophobe chains. Acids fat form vesicles provided that the hydrocarbon
chain contains at least ten atoms of carbon.
However, membranes produced by means of these amphiphiles compounds simple are stable only in a narrow range of experimental conditions, so that more complex chemical compounds were credibly necessary to confer a good stability on the primitive membranes.
Nucléids acids current carry the genetic information which allows the forming of a cell-girl identical to the cell-mother. They are very long chains constituted by the rehearsal of nucleotides. Every nucleotide consists of a sugar (ribose endowed with a group OH for the ARN, desoxyribose for the DNA), of a base (purineA, G or pyrimidine T, U, C) and of a group phosphate.
The establishment of connections hydrogenates allows the preferential matching of bases. Thanks to the matching of bases, the DNA adopts a stable conformation in double helix constituted by the association top-to-tail of two stalks additional polynucleotides. The matching of bases also supplies in the DNA the means to transfer the information which it carries printed in its sequence by a mechanism of auto replication: both additional stalks part and each of them serves as matrix for the synthesis of a new chain. The copy is made with an excellent precision because the rate of mistranslation is of the order of an amino acid on ten thousand.
2.3.2 Of which are we made ?
We are constitute of eucaryotes that is of cell with nucleus.
The bodies of Golgi (which store the products of the metabolism), mitochondries (which supply the energy)
From the adenosynetriphosphate or ATP) and chloroplastes (producers of chlorophyll for algae and plants) is former bacteria which merged with the primitive eucaryote.
The genetic patrimony on base of DNA is protected by a nucleus itself .
On the contrary, procaryotes ( archeobacteria and bacteria) is only small cells or the DNA floats freely
The discovery of thermophile archeobacteriawas able to create them one moment as our ancestors. Now it does not suit to the more likely hypothesis of essential bodies base on the RNA and not on the DNA.
Apparently bacteria and archeobacteries form two different families and not original of our own family Eucaryotes. Our ancestor, LUCA (Last Commun Ancester), would be common to three families.
Eucaryotes cannot survive beyond 60°C, the bacteria of 95°C but some people archeobacterias can resist in 110°C.
Now the bacteria the cellular mechanisms of which seem particularly effective, do not seem to have been able to give birth to present much more complex mechanisms to eucaryotes, such the splicing (mechanism used for the transcription of the genes, the assembly of the coding regions or exons and elimination of the not coding regions or introns).
The molecular mechanisms eucaryotes remind the result of a craft do-it-yourself which would have preceded the effective but sophisticated processes of procaryotes (bacteria and archeobacteria).
Now the bricks of the DNA (desoxyribonucleotides) are produced from the precursors of the RNA (ribonucleotides) .
RNA has of to invent proteins because the forming which associates amino acids between them in proteins is still realized in the current cells by an enzyme constitute of RNA, a ribozyme (catalyst looking like enzymes on base of DNA). In fact ARN, as DNA, can pass on of the information and catalyse the chemical reactions as the proteins .
Now the bodies on base of DNA are easily thermophiles if the possible breaks are avoided by an environment with strong concentration of salt what is not the case of the bodies on ARN's base, this concentration of salt accelerating the breaks there. The first bodies on ARN's base would be thus rather thermophobes and thus different from archeobacteria.
In fact the life did not at first have to develop in kettles with high temperature in the presence of the good concentration of magnesium to avoid the destruction of the RNA.
The life has of to wait for the invention of the DNA to develop in circles with high temperature.
LUCA must have developed in a moderate environment of 20 in 50°C .
He was to be closer to eucaryotes than toprocaryotes and possessed as them mechanisms separated for the transcription and the translation. The adaptation to the high temperatures pulled the coupling between 2 mechanisms, reduction of the size of the genome and increase of the speed of the cellular reactions: thethermic shrinking .
Besides a known enzyme, the gyrase, necessary reverse for reinforce the links between 2 stalks of the DNA in all the bacteria and thermophile archeobacteriatoday known, was established only late in the evolution because it is the product of the fusion of two more primitive enzymes .
And there is no known thermophile eucaryote !
Thermophile organism is not thus archaic but modern.
It would also seem that the thermophilie of bacteria is a recent adaptation which would have occurred several times and independently in this family.
Besides, there is archéobactéries psychrophiles that is liking the cold!
It is necessary to abandon the primitive and Darwinian vision of the evolution as a process aiming at the adaptation in the complication . The life is opportunist; it uses resources useful but not foreseen for that purpose and she can adopt the simplification rather than the complication for her survival.
The fortuitous presence to archeobacteria living in the cold of lipids allowing the resistance high temperature could be seen as an illustration of this opportunism. At the moment it is not possible to cut between a warm or cold origin of archeobacteria .
We can imagine that procaryotes arises fromeucaryotes by thermic shrinking producing at first the creation of thermophile archeobacteria , that bacteria are a by-product of a particular lineage of archeobacteria, those living in the cold and what the adaptation to the thermophilieof bacteria are made in a second time.
Other scenarii of creation of eucaryotes bases on the fusion of a bacterium and an archeobacteria.
And, even if the life appeared to high temperature, she had to develop in low only compatible temperature of the development of the world base on the RNA.
Bacteria would possess a total mass close to the mass of all the ground plants which are responsible only for the photosynthesis, the procaryotes being responsible for all other chemical processes such the constitution of the molecular nitrogen of all the alive organisms.
These generally asexual bodies acquire their varieties by processes of extremely fast alterations. We can expect that a gene shares by all the bacteria acquires 4 simultaneous alterations every 10 minutes. More than 90 % of bacteria would come from maritime and ground basements participating in the geochemical transformation of the Earth.
In fact the alive world is separated in viruses and cellular bodies ( eucaryotes and procaryotes).
The current viruses need to infect specific cells to prosper.
Now the genome of the viruses is a mosaic of genomes of previous viruses form by recombination what complicates the phylogenetic reconstruction.
The cellular bodies have every similar characteristics: genomes under shape DNA-RNA, DNA (enzyme synthetizing a new DNA from a stalk of DNA matrix), machinery of transcription (synthesis of an ARN messenger from a matrix of DNA) and of translation (synthesis of proteins from the message of the ARN), energy systems. All these characteristics were not able to appear simultaneously at the first alive body.
During the phase meadow biotick have of the set up being the mechanisms of replication of nucléus acids and of the genetic code allowing the passage of the nucléus acid in proteins.
Now viruses not adapt to the raised temperatures (with a head and a tail for the movement) seem more former in the genealogy than the viruses with stiff and filamentous stalk which can resist to high temperatures.
Besides, we observe similarity between polymeric ARN of the mitochondria which are of bacterian origin and polymeric ARN produced by viruses consumer of bacteria. It seems likely that the cellular body acquired polymeric ARN of viral origin; the viruses would have been a stage necessary and previous to the blooming of the cellular bodies.
But this field of viral research is at its beginning because of the
viral variety strangely bigger than the cellular variety there.
2.3.3 Table of the characteristics
|Type||Origin||Environment(Middle) of life||Characteristics||Impact|
Potential of living
|Thermophile ( hot +80°C ) and mesophile (+20°C - 80°C)||Depends eucaryotes
for expression and
|Cellular organisms: procaryotes (bacteria)||Archeobacteria||Thermophile||Generally asexual||Responsible for the chemical processes|
|Cellular organism: procaryotes ( archéobactéries )||Eucaryotes||Thermophile and psychrophile (cold 5 - 20)||Asexual||Responsible for the chemical processes|
|Cellular organism: eucaryotes||Symbiosis of bacteria (body of Golgi and for plants only of chloroplaste ), of virus ( mitochondries ) and procaryotes in nucleus of DNA||Medium||Generally sexual||Responsible for the photosynthesis and the biologic processes|
Sources The Research n317 in February 99 The borders of the alive
2.4 Evolution of the genetic message
The duplication of 2 ribbons crossed by DNA engenders errors of copy. This one strikingly constant is 1 by one billion pairs, that is 10 errors in every duplication of human cells. This precision is due to mechanisms automechanics which tracks down and rectify the errors of copy.
A consequence of the errors is that the ribbon of DNA lengthens continuously and in a quite linear way, at the rate of a factor 10 - 20 by one billion years.
Parts furthermore in longer of the message are thus inconsistent and unused (introns).
These alterations are generally without impact but can reveal a useful characteristic for the survival and the reproduction of the individual.
The comparison of DNA sequences allows to reconstitute phylogenetic trees by determining the rate of distance between the taken bodies two - two.
So of the ribosome used by the DNA to constitute proteins by means of amines acids.
Copies out it of the coding sequence of the DNA in an RNA messenger who takes out of the nucleus and meets ribosomes. This one, formed by RNA and by proteins, slides along the ARN messenger and copies out it by means of RNA of transfer. Those this are RNA's ends which carries in an extremity 3 not mated bases and of the other one quote an amino acid. If 3 bases which stick to the ARN messenger mate in 3 bases on the ARN messenger, the associated amino acid add to the chain forming the protein. ARN of transfer is going to follow by succeeding one another the road of the ARN messenger until the completion of the protein.
The tree which results from it is potentially constituted by 2 million branches and indicates without ambiguity that a ramification and thus a number of branches which is reduced by going back up the complexity.
This ramification thus places its source in a common origin, even if the type of body was not able to be clearly identified.
An alive system is a dissipating structure opened on the outside which increases its internal organization by rejecting towards the outside of the molecules of lesser organization.
The growth towards more and more complex organizations is connected to not linear phenomena which appear during the feedback (self catalysis, inhibitions, activations).
Besides the alive bodies are constituted gradually.
So we evoke hyper cycles constitute of an association of chemical feedback which act the one on the other one. If one of the reactions is less adapted, it tends to remove the hypercycle, otherwise it strengthens it.
It is about a Darwinian mechanism of selection at the chemical level
2.5 Research ways
Since the first experiments in 1953 of Stanley Miller producing half of the acids amines necessary for the life in a reducing atmosphere, the experimental progress is weak. The proliferation of similar molecules in the produced soup indeed seems to block the development of more evolved substances.
Besides, the geophysicists tilt rather for an oxidizing atmosphere on base of carbon dioxide and not methane. Some people saw in the space, the germs of the life. If the production of numerous amino acids in the molecular clouds seem to indicate the proliferation of ingredients necessary for the life, the support of its development is not still known.
Some have imagine comets, for the others deep thermal springs. In both cases, it seems not very probable that the life develops in conditions so extreme, although a credible scenario bases on the assimilation of carbon of the carbon dioxide by reactions with the sulphurous hydrogen by an "primordial" molecule to the surface of pyrites of volcanic origin. But the temperature of 300°C of the fluid seem to compromise the development of a chemistry meadow biotick.
An interesting way anyway seem to be the use of certain minerals as matrix. The crystals of clay were considered as good candidates by Desmond Bernal from the 50s.
The clay crystals of which can grow is also a good candidate, the organic matter constituted in stalk of nucleus acids winning finally its autonomy with regard to its matrix.
These stalks would have constitute primitive, simplified RNA. RNA is capable of chemical synthesis and research ways turns to the selection of in vitro RNA, to select forms which would have been able to exist in past.
The study of the current cells and their fashion of functioning apparently pointlessly complex could also be the track of the side streets which has take the life. In a sense, fossil residues.
The interest of the researches for the chemistry meadow a biotick over
Mars, Titan or Europe remains which can guide strongly the axes of studies
in evolution meadow biotick...
2.6 The epic of the life
During more than 2 billion years, the Earth will not know that bacteria.
There is 3,4 billion years (even 3,8 billions), monocellular bodies appeared which such the bacterium of the lactic acid fermented organic molecules supplied by meteors or comets.
Then the monocellular blue algae came which, through the photosynthesis, extracted the carbon of the carbon dioxide and threw back the oxygen. The content in oxygen of the atmosphere reached 1 %.
3 groups form urcaryotes (our lineage), bacteria (which notably govern a big part of the geochemical processes of the planet) and the archeobacteria which do not resist to the oxygen and took refuge with niches today (the sulphurous sources for thermo-acidophiles, digestive tracts or swamps for the methanogenes ones which used the hydrogen today disappeared from the atmosphere).
Thanks to the increase of the content in oxygen and to the consecutive forming of the ozone layer defender of ultraviolet rays, bacteria do not remain to border any more in deep water.
The sexuality, crossing of patrimony differentiated to multiply the experiments appeared here is 1 billion years.
2.5 The explosion of the Cambrian
Here is 600 million years the oceans saw the explosion of very diversified multicellular forms of life of which a tiny survived fraction. At the origin of this explosion maybe the end of an era of massive glaciation. Because the young Sun had a temperature of surface less high than today, the temperature on the surface of the Earth was maybe low with the massive reduction of the carbon dioxide by fixation in carbonates, rather low to explain the visible erosion massive as under the influence of iceberg of certain zones of former cliffs. We so reconstitute 3 major phases of glaciation dating 2,4 billion years, from 900 to 800 million years and finally from 700 to 650 million years. The access to the sun light of portion of oceans taken by the ica floe explains maybe this " explosion of the Cambrian ".
In this time continents were still totally sterile.
Here is 350 million years the first plants appeared, as well as the insects which colonized continents.
The apparition of plants with flowers and the phenomena of symbioses with insects quickly spread the vegetable coverage. The organization of insects became even more effective for the last period with the apparition of the social insects, there is a little more than 100 million years.
Plants by consuming the CO2 made decrease very strongly the greenhouse effect, by increasing at the same time the oxygen until its current content. The decrease of CO2 reduced the vegetable mass.
But the oxygen remained a poison.
A new branch thus appeared after insects to take advantage this unexploited resource by inhaling it: ourselves, the animals.
First of all came amphibians, intermediate stage between the ground and aquatic animals, then quickly the purely ground animals reptiles then mammals. The first ones of this animal order appeared here is 250 million years .
The strongly exothermic reaction
based on the breath of the oxygen allowed animals a continuous movement
on the Earth to take advantage of the vegetable coverage, an also quick
movement what allowed to integrate insects into the food as well as the
animals in the pursuit of the aquatic fight.
2.6 The choice
Plants divert 25 % of the CO2 in their own usage since 350 million years. When they die a part of the produced carbon the decomposition of the organic matter oxidizes and returns to the CO2. Other part passes in the ground.
Hydrocarbons are the result of this burying of the carbon in the ground, essentially by the luxuriant plants of the Carboniferous period.
Today the Man expels hydrocarbons in the atmosphere as well as the sulphurated components.
These two elements tend to increase quickly the greenhouse effect .
By-products such fluorocarbures also has a destructive effect on the ozone layer.
The rate of carbon dioxide so increased by 25 % since the beginning of the century.
Because of the importance of the ocean and the dozens coming into play factors, it is difficult to estimate the evolution of the temperature. Only a variation of a degree was until then noticed.
But the pursuit of this movement can lead to two situations.
If the natural feedback allows the limitation of the greenhouse effect and, in spite of the variety of the notably sulphurated discharges, the temperature would stay in the range already reached before the Carboniferous period (rise from 10 to 15 degrees)
If the feedback does not compensate for the greenhouse effect a positive feedback can appear and the engendered difference can eventually provoke an unverifiable increase of the temperature and the disappearance of the oceans.
What is essential is that the models do not as is allow to end formally on the impossibility of this thermic difference.
Let us summarize the Earth history
4,55 billion years Forming of the Earth
4,45 at the beginning of the ground bombardment by asteroids and comets. Forming of the Moon by collision of the Earth with a mini planet.
4,3 at the end of the extensive meteors bombardment
4 apparition of continental pedestals by accumulation of carbonates
3,8 apparition of the life from amino acids of the heart of the carbon chondrites (meteors)
3,6 at the end of the extensive comet bombardment
2,7 apparition of the first blue algae and the eucaryotes
- 2 profusion of the blue algae (gone up by some atmospheric oxygen to 1 %)
1 apparition of the sexuality
0,6 explosion of multicellular branchs
0,4 apparition of the first ground plants
0,3 condensation of the carbon dioxide by plants (the oxygen rises to 21 % and the carbon dioxide disappears)
0,2 apparition of the big animal orders: reptiles, mammals and birds
0,1 stabilization of the social insects
0,04 apparition of the primates
What will make the Man?
An ecosystem in interaction: impact on the evolution
The ground atmosphere is a fine film of gas the thickness of which is the hundredth of theEarth radius. This fluid transports the heat engender by the thermic engine; the major part of the energy is dissipated by winds, more than by tides, oceanic currents, continental drift and convection of the ground coat gathered.
The composition of the dry air is strikingly constant on the area of the Globe (78 % N2 produces by degassing of cliffs and which accumulates because geochemical sluggish, 21 % O2 produces by the life and which retrains constantly between the atmosphere, the oceans, the biosphere and the sedimentary rocks, 1 % Ar produces by radioactive decomposition in the coat and the earth's crust and degased by volcanoes).
On the other hand the quantity of steam varies some thousandth in 4 % of the volume.
The water is mainly under liquid shape, the ocean condensing the equivalent of 300 atmospheres exclusively of water
The quantity in carbon dioxide as the quantity of steam is fixed by the quicknesses of reaction of balance binding the atmospheric reservoir to the reservoirs of surface.
If the CO2 forms 340 parts by one million dry airs, the atmospheric reservoir is less important than the oceanic reservoir and than the reservoir of carbon of calcareous rocks, which contain to them only the equivalent of 20 atmospheres exclusively of dioxide of carbon.
Only the other essential gas is the ozone (O3) the density of which reaches its maximum towards 30 km in height: 12 parts by one million
The photodissociation of the molecular oxygen by ultraviolet rays allows to release atoms of oxygen which harmonizing in O2 form the ozone which on the contrary filters the ultraviolet radiations.
Reactions destroy at the same time the ozone notably reactions as base of chlorine.
The sun stream is actual 1367 Watts by metre square on the verge of the atmosphere.
The atmosphere and the surface reflect 30 % ( the albedo) notably by clouds, dusts, atmospheric molecules and snow. The clearing increases the reflected radiation .
The temperature equivalent of 240 Watts thinks by the Earth is that of a thermal radiation of black body of-18°C; the atmosphere emitting towards the ground and the oceans allows the average temperature of the globe to gain 14 or 15°C.
The local imbalance of absorbed energy or emitted in surface create horizontal or vertical thermic pressure gradients in the atmosphere .
The Earth absorbs more energy in the low latitudes than in the high latitudes.
More half of the energy is absorbed by the Earth, the rest by the atmosphere. The conjunction of these two facts leads to a temperature which decreases of the equator in the poles and the low heights upward the atmosphere.
There is so a cold stratospheric layer which prevent a strong evaporation of the oceans. On Come the absence of such a layer would have contributed to the difference of the temperatures.
The big cells of convections connect the warm and wet air of the equator with the warm and dry air of the tropical latitudes. The air which rises cools pulling intense precipitation between the latitudes +/-10 (zone of intertropical convergence).
The air made dry goes to the poles and passes on the particularly dry subtropical regions; the big deserts are situated between 10 and 35 of the latitude.
Beyond the currents is - the West pulled by the effect Coriolis determine the drainage of air; the air masses imprisoned between crests and hollows of the long atmospheric waves characterize the movements of the zones of high and the low pressures and thus the time on the average latitudes.
The particular arrangement of the mountainous chains on both sides of the Atlantic Ocean the North make that the air moistens when it crosses the Atlantic Ocean; oceanic waters of surface concentrate in salt and become more dense; they plunge and begin a global traffic which redistributes the salt.
The Atlantic traffic engenders Gulf Stream and brings 8 degree waters over the current which comes down southward; the sweet European climate ensues from it.
We explain the recent glaciations by a sudden contribution of iceberg coming from Canada which, diluting the quantity of salt, interrupt the traffic of GulfStream .
Any stop would affect in Dublin the climate of Spitsbergen and this within ten years.
Hundreds of thousand years would be needed so that the distribution of the salt of the bottom towards the surface decreases enough the abyssal density to revive an oceanic traffic.
The climatic modification is global because the stop of the currents
of traffic in the Atlantic Ocean would modify the winds of the tropical
atmosphere. A modification of the cells of tropical
convections reduces eventually the quantity of cold
water surfacing of the Pacific; a phenomenon of type El Nino engages for
at least one thousand years with considerable precipitation on the American
tropical zones and aridity on Oceania and east Asia.
3.2 The chaos and the life
The balance of climates: the couple extraordinary Earth the Moon
The ground equator is tilted by 23 degrees with regard to the plan of its orbit.
Now the combined effect of the Moon and the Sun on the ground equatorial led swelling a movement of precession on the axis of rotation of ground which makes it describe a rotation of a period of 26000 years around a fictitious axis.
This movement of the type undergoes by a top in rotation when it undergoes a lateral push leads to the precision of the equinoxes, discovered by Hipparque here is 23 centuries.
The long-term influence of the other planets also makes undergo in the ground axis of the variations of the order of 1,3 degrees responsible for the periods of glaciations and for reheating.
But the absence of the Moon which counts for 2/3 in the effect of precession of the equinoxes would lead a precession of a period of 75000 years and either of 26000 years, entering phase and thus cumulative echo with the disturbances of the other planets.
The result would be typical variations of the orientation of the ground axis of 50 degrees in 2 million years what is incompatible of the rhythm of possible superior adaptation of forms of life.
In fact for durations of ground rotation from 12 to 48 hours the slope of the axis, without the Moon, could vary in a chaotic way from 0 to 85 degrees.
The Moon the origin of which would be the accretion of fragment result of the collision between the Earth and the planet of the size of March at the very beginning of its history would thus be a necessary presence for the blooming of the evolved life, a probably rare phenomenon...
It is not thus enough any more to find a planet at good distance of its Sun so that the evolved life is possible for it.
There where the knowledge of the chaos joins that of the life in the
3.3 The new departures of the life: Sun - Asteroids - Jupiter
The term chaos means being the object of sudden variations due to a so small cause as it seems unpredictable.
In the case of the belt of asteroids, it was determined by Jacques Wisdom whom the disturbances of Jupiter on the asteroids of third period with regard to orbital period of Jupiter modify gradually their trajectories to the point that the eccentricity of their pseudo -ellips increases and to the point that they eventually collide the Earth or in March, where from their progressive rarefaction.
Unlike the echo 3/1, the echos 3/2 do not correspond to a chaotic zone because asteroids tend to be grouped together there: it is about a well of stability.
In the case of the echo 2/1, it is about a zone where the density is gradually reduced but the hypothesis of the chaos is insufficient to explain this deficit because these asteroids far from the Earth and of March have a very weak probability to collide them and to disappear. On top of asteroids on chaotic orbits can be confined in precise regions. We speak about stable chaos due to a periodicity which prevents them from touching Jupiter ( rememberSchoemaker-Levy comet). If the reports of periodicity are not whole, the influence of the massive body is not periodic and does not allow the trajectories to diverge.
Concerning some hundreds of at present identified asteroids trajectories of which cut the ground orbit, nobody should strike the Earth during the next two centuries.
But the collisions with asteroids had devastating effects
provoking the equivalent of nuclear winters and destroying all the
ecological chain. This probably engendered phenomena of massive extinctions
and new initializations of the
process of the evolution.
4 The origin of the origin
Creation of the galaxies and the invisible matter.
The forming within a billion years after Big-Bang of the first galaxies requires to bring in germs of concentrations before even the forming of the first atoms and the emission of the Cosmological Microwave background radiation. The origin of these necessary fluctuations is not known.
A simple development of essential variation connected with the quantum uncertainties seems insufficient.
On the other hand, the density of the universe deducted from the measures of the essential elements (Deuterium, Helium, Lithium) and the hypothesis of relativity which supposes a homogeneous density in the universe ends in an average density in agreement with the density deducted from the stability of the star clusters.
But this stability of the heap is incompatible with the moderate average speeds of the forming galaxies heap She can be assured that if the density of attractive matter is approximately ten times that of the matter discovered by brilliance. This density deducted from the hypothesis of stability of the masses (theorem of Viriel) is thus close to that deducted from the models of nucleosynthesis for the observed proportions.
But of what is this invisible matter?
Can it be made of a classic matter but the values of masses of which must be revised: massive neutrino?
Maybe of an exotic materter deducted from the models of unification of the forces of the Nature but our laboratories do not allow us for the moment to discover these new classes of particles.
The meeting of the infinity
The uncoupling light - matter: Fiat Lux and first atoms
The fractals fluctuations (or a particular shape of insensible matter in the smoothing by expansion): the germs of concentration at the origin of heap galactic < 700 000 years
The life expectancy of the free neutron: a quarter of an hour to create the essential matter
Asymmetry of the weak destruction: the matter as the billionth of the world
The interaction photon - producing photon of matter antimatter 10 -34s
The big transition: the birth of the interactions 10-35s
The space rather than nothing: Heisenberg
5 The Big-How : the question of anthropocentrism
5.1 The Question
The science in the last years of the century was marked by the discovery of deep links between all the scales of the cosmos. The origin of this infinitely big universe cannot be understood without a model describing the genesis of the elementary particles and their interactions. The origin of the alive cannot too be determined without the understanding of the chemical phenomena describing the genesis of the metabolism and the support of the genetic information. The apparition of the man, and it is the big novelty, cannot be separated from the chain in all the scales and in all the times of the nuclear, gravitational and electromagnetic interactions and especially in the remarkable values of the parameters associated to these forces. We do not know today if these parameters are free or forced. We do not know if the universe is unique or multiple. And if it is unique , he would have been able to be the other .
The major fact is that the visible unlikelihood of the phenomenon of the alive imposes a vision of what the whole universe constitutes. It is the anthropomorphic approach of the origin even of the meaning of the universe.
There are two versions of this approach.
The first one is said weak. It determines what are the constraints compulsory for the universe to make it compatible with observers' presence. It aims at estimating acceptable intervals for the parameters of the fundamental laws.
In view of the unlikelihood of a fortunate fate having led in a stochastic way to the Man in a unique universe, this approach led to two possible conclusions.
The universe could be multiple, and we would be in one of those benefiting from observers.
We could also be in a zone of the universe convenient to the life where the universe could have evolved so that in our time the life is possible.
The second anthropomorphic approach of the existence of the universe is said strong.
It justifies backwards the universe as taking its source in the necessity of the Man; the Universe takes his source in the consciousness of itself. This approach asserts the deep link between the origin of the Universe and that of the Man.
This second approach bends over the extraordinary aspect of the phenomenon of consciousness which allows us to understand our roots and to express all our freedom in the stiff frame of the fundamental laws. It leads to a research for the similarity between the universe and the man. It puts the consciousness of the universe by the man as the essential fact by which the universe takes source.
It ends in two opposable ideas: the notion of initial will immanent in the universe aiming at creating the man (God makes the man) or the idea the opposite of the Universe as a human construction (the Spirit of the Man is a God) .
The fundamental question which is put to us is the comprehensibility of the World. The application of models by the filter of the mathematical quantification allowed us a description of the World. Is this application a construction of the Man by whom we give a sense and a coherence?
Why the Mathematics?
The World can be described by the mathematics which reflect its organizations and the relations which the Nature has establishes in each of the parts.
The Man inclines the capacity to elaborate a mathematical model of these properties .
The mathematics base on our capacities of counting and geometricians.
The capacity of quantification was given to the Man because it is a not only gregarious but social animal; he has to proceed to a distribution of the possessions between the members of his group. It is thus necessary to him to count its possessions and its troops.
The capacity of geometrician is necessary for any animal which moves in a variable environment. Outdoors, the sight is the most adapted tool because the information which he gets is immediate and available all the way of the time of the day before. The binocular vision of the tool allowed him to develop its hunter's capacities. The acquisition of the sense of the vision was thus the angular stone of the geometry .
Hardly of these two necessities of survival and social development, the Man acquired mental tools which allow him to model his environment and to grap the Nature .
There is thus correspondence between a need of survival and a cultural need; the tool was able to be diverted.
Nevertheless, even if the tool showed itself formidably predictive and productive, the surprise in front of our own understanding, must be always moderated by the idea which we understand only what exists in our scale.
The quantum physics questions the notion of separation and switching; the paradoxical quantification does not work any more so well.
Also at the macroscopic level, notions of indefiniteness are daylight and the integration in the mathematical frame finds its limits. The research for the orders of cardinality (transfinity) develops around this axis.
Even in our scale, the indistinctness of the measure deprives gradually of our tools the capacity of prediction. This impossibility to predict a result even if the process is completely quantifiable in equation was named chaos.
The notion of mathematical,axiomatic
construction of the world, also finds its limits because there are sets
propositions self coherent different some of the others ( several mathematical
models) and, within the framework of an axiomatic
set, there are undecidables propositions.
Why do we say that the life is improbable?
A computer process is the passage between 2 states. Supports can be of very different types (mechanics, electronics, optical, biologic).
The life is the progressive modification of the program by the interaction with the environment by selective pressure or new opportunity to use this environment optimally, in the sense of the physical growth and the perpetuity, a shape of which is the duplication.
The consciousness is the capacity to use its memory to modify its reaction towards the environment.
Under these definitions a big number of processes seems to lead to the consciousness. This tends to indicate that natural laws different from ours can also end in the state of consciousness according to times more or less long. The perception of the duration of the universe by the aware being will always be on the scale of its rhythm of consciousness; a consciousness with slow transition in a world evolving very slowly will have the same perception of the duration of the Evolution as ourselves.
The fact of focusing us on the impossibility of the life without particular conditions makes us the opportunism of the natural processes forget which leads by the unpredictable phenomena ends in forms of automobile organization surprising. The structuralization of a massive star is hardly less surprising than the life itself .
The physical theories tend to indicate that the structure of the World in natural laws, described by the coupling of the elements of matter by the processes of interaction, is a natural process. But we can imagine laws modified in their intensities even in their forms.
Different natural constants would end in the other forms of organization. The problem which arises then is the fight between the processes of cosmic expansion (and of dilution of the resources) and of the auto-organization; in fact the margin of the cosmic parameters is limited to end in forms of aware auto-organization before the depletion of ressources.
An observation: the separation of the universe in independent domains and the hypothesis of a universe connected without break from a domain to the other one allowed us a description susceptible to lead to evaluation, to confrontation with the measure.
And if one not separability or an indistinctness gets into the models the absolute prediction is replaced by a relative prediction, described only in term of probability.
We are confronted with a dilemma. If the parameters of the World are free, then our coming is surprising, improbable and we ask then the question if the observed universe is only a small part of a big everything (multiple universes or universes in the laws would evolve in the time).
If the parameters of the World are forced, then we ask us why for it are they in this way precise? Is there initial will or the question is not it falsified by our anthropomorphism?
There is any more actually no school which would separate fundamentally the process of life of the process leading to the consciousness. At the most the apparition of the consciousness adds a supplementary unlikelihood but the notion to exist just seems an effect of the confrontation between the perception of the present and the memory of immediate past. This memory is a reference necessary for this capacity of forecast which developed in the fight for the survival. The creation of the immediate memory and the long-term memory notably to the superior mammals introduced thus naturally the notion of time which passes by and thus the notion of consciousness. The time, unlike the measures of physical variables (position, energy, impulse) is a sort of méta variable, not measurable directly and, because it is about a relative notion, she expresses himself only by the comparison of series of measure grips by different observers.
The animal species thus reached gradually the consciousness by the integration of a model of the environment which allowed them to photograph, to interiorize the World (an external entity by definition) .
The true question is not thus the surprise in front of the apparition of the consciousness but indeed to know if the life in itself is remarkable with regard to the other evolutionary processes of the universe.
The life is the meeting of the metabolism (who allows to maintain a dissipative structure, opened on the outside) and of a double capacity of contagious capitalization of the experience added by a variety to assure the flexibility and the resistance in front of change of environment.
It assures temporary islands of order in front of a tide of disorder growing (the entropy)
Is the existence of such a process remarkable?
Is there in the same universe of the other phenomena so remarkable of complexity even if they have observers' status and thus of aware phenomena, in an act of separation from the World.
And if it was possible to change the parameters, there would not be more remarkable still than the life in our universe, this life being characterized by a consciousness limited in the time and in the space.
We could imagine for example, an universe which intrinsically by its structure and its laws would form a global and indivisible consciousness while keeping a capacity of evolution. A sort of hypothesis Gaïa on the scale of a universe .
In the horizon of the knowledge,
we introduce the values of the constants of the nature but we forget
the no-linearity that is the sensibility
on the initial conditions. Does it exist any process which, without the
quantum indecision, require a higher time for the measure than the time
necessary for the process to evolve of a size superior to the precision?
5.2 Why the World is such as it is?
Because we can observe it
It has only 3 dimensions of space
Reduction of a space with bigger dimension
In the theories of big unification the nuclear and electromagnetic fundamental interactions are only the product in our space-time of the existence of different dimensions.
Only 3 dimensions of the space and time would be expanding, the other dimensions would have curled up at the very beginning of the universe.
- Only a space in 3 dimensions would allow:
- The stability of the atom (harmonious frequencies of the function of wave)
- The stability of orbits (gravitation)
- A self- sufficient complexity (a space plan would generate no complexity)
A single dimension of time: otherwise no conservation; all the matter would be transformed spontaneously into radiation and conversely.
Conjunction of the sizes:
The report of the characteristic constants of coupling of the gravitational and electromagnetic interactions = report between the dimension of the observable universe and the size of the proton
Now if we put as unit of time, the time put by the light to cross a proton, then the necessary time for observers' apparition (stellar genesis and preservation of a sun of size averages on the main sequence) is appreciably equal to the report of constants.
The size of the observable universe; it is directly connected as observers are capable of studying the universe. Its value brings no information because it is about a tautology.
Spatial curvature: almost flat universe
The universe is almost flat. But the distance from curvature quickly diverges in time; the initial universe was flat (in 1060 Near): this explains by the leveling caused by the process of inflation at the very beginning of the universe.
Isotropic universe: the homogeneous universes with weak curvature become isotropic: the isotropy is not thus remarkable in itself.
A cosmological constant almost equal to zero
If it was positive and important the universe would be diluted
If it was negative and important, the universe would quickly collapse
A report between the stream of photon of the cosmological diffuse bottom and the number of material particles of 109.
If the report had been much higher, the cosmic microwave background radiation would have been too warm and stars would have disappeared before the life cannot form (absence of liquid water on the surface of planets) .
If the report had been superior to 1010, the galaxies would have formed with difficulty
On the other hand, the germs of the galaxies were to be important enough for not being levelled by the expansion before the light- matter uncoupling before the forming of the cosmic microwave background radiation, thus a report superior to 106.
The entropy of the universe is weak; very few black holes of weak size formed at the beginning of the universe because their waste and their disapparition would have emitted the streams of very important radiations in the universe, where from an extremely strong constraint on the characteristics of the essential peculiarity.
The value of the constants of couplings
These constants determine the intensity of the fundamental interactions. They seem constant during time by the observations of the radiation of the distant galaxies.
The gravitational constant must be high so that the universe splits one multitudes of stars: so many potential sites for the life the hatching of which according to the biologists and on the evolution towards an self-aware shape bases on a multitude of roads the probability of which is very weak .
If the constant had appreciably been weaker, stars would not have undergone phenomena of convection of surface which seems connected to the inclination of forming of solar system. The strongly convectives dwarf stars seem those possessing the weakest moment of rotation where from the hypothesis that this moment was acquired by a planetary system.
If the constant was higher, stars would be homogenized by the convection and we would have no structure in onion skin in supernovae and almost no metal enrichment of the galaxies.
Constant of weak interaction
A higher constant would have engendered a massive transformation of hydrogen in helium during the essential nucleosynthesis : stars would not have enough lasted for a long time and the most massive only ones would have had the sufficient temperature to start the fusion reaction.
Besides the impulse of neutrinos (produced by the weak interaction during the production of the heart of neutrons in supernovae) on the external layers allowing the eviction of the metallic core requires a rate of interaction of neutrinos with the matter of the same order as the interaction of the matter with itself during the fall of the internal layers: constants gravitational and nuclear weak are strongly coupled
If its value was 3 times as strong, there would be no other atoms that the hydrogen but if it was 3 times as small, there would be no neutral atoms.
In fact, if the constant was different, the field would quickly be diverging and thus unstable (infinity would be engendered during the calculations said of normalization considering the field at a quantum distance of the electron, source of the field).
Strong nuclear constant
If the constant was weaker, there would be no pits and thus that some hydrogen
If it was stronger, the most massive pits would form too fast because they would be the most stable.
Besides the forming of the carbon (cycle CNO) depends very strongly on this value: the level of energy of the carbon allows the beryllium of just credit note the time and the abundance to produce some carbon by fusion with the helium. In contrast the absence of a level of energy favoring too much l production of oxygen prevents the carbon from being too much transformed in oxygen.
A 5 % change of the constants of coupling would be enough to stabilize the shape 2He what would have removed the hydrogen during the nucleosynthesis and shortened any stellar forming.
The fundamental characteristics of particles
The life requires a ratio mass proton / mass very particular electron. An much higher electronic mass would increase strongly the quantum uncertainty on the positions of the ions and would return the geometrical much more unstable structure of molecules.
Imbalance matter antimatter requires to bring in a law of unification of the interactions which notably foresees a slower rate of destruction of the matter assuring its superiority on the antimatter.
In this theoretical frame, the abundance of the helium requires the 3-doubloon existence leptons quarks. In turn these 3 doubloons assure the partial violation of a symmetry load parity allowing a big stability of the first doubloon quark constituent electron of the common matter.
Besides the process of the alive requires a universe in imbalance thermodynamics and thus expanding.
Let us summarize: an universe where the alive is possible is expanding, and its interactions unified originally admit only 3 doublets lepton quark.
Remark of Carr and Rees: if a fundamental law explained the value of the constants of the nature, it would remain not less remarkable there that this law allows the life.
Weak principle: the measurable characteristics of the universe by an observer are such as the life was able to develop there.
Strong principle: the universe is such as the life has to develop there
Ultimate principle: the universe is such as its final state is to be completely occupied by the consciousness. It is a possible explanation of its origin if the universe can temporarily close.
But this problem and our surprise in front of this universe directed by or to the life must be moderated whom the man is himself a filter in the measures and that our real universe is can be that visible.
The chain which allowed the life
5.3.1 The cosmic Chain
Table of the processes leading to the apparition of the Life and
to the development of the consciousness
|Symmetric and perpetual universe||Quantum fluctuations||Orientation of time
Spatial expansion and location(localization)
|Unhomogeneous universe||Dimensional break : gravitation and atomic forces T=1032K||Inflation and smoothing of the fluctuations|
|Universe without material particles||Break nuclear strong
and electroweak interactions
( T=1013 K)
Matter-antimatter from the particles of interactions
Matter and gregarious antimatter / Matter and exclusive antimatter / Particles transporting the interaction
|Condensation quarks in neutrons
( T=1012 K)
|Fundamental particles of nucleus|
|Mix matter antimatter||Cooling
|Stop creation particles: destruction
takes the step.
Antimatter = 0
|Free particles||T=10 Nucléosynthesis (10K)||Ionized plasma (hydrogen, helium)|
|Expanding universe||Fluctuation||Growth of germs
Of critical size
( T=4000 K )
|Opaque universe||Uncoupling of matter / radiation||Cosmic microwave backgroud
|Mass of expanding atoms||Aggregation by revolves||Gas masses|
|Expansion||Cooling||Pressure brilliance on clouds: ionization|
|Uncomplete uncoupling Matter / radiation :reliquat free electrons||Catalyse H2 by electron||Cooling clouds:
1st forming star where from massive ionization gas and stop stellar forming
|Scattered stars||Aggregation by gravity||Star cluster|
|Heap scattered||Aggregation by gravity and black matter||Galaxies|
|Universe = H and He||Fusion in heart of stars||He, C, O + metals for catalysis fusion in stars 2nd generation|
|Uniformity of the distributions of the atomic elements||Dispersal masses||Fork of the stellar evolutions|
|Interstellar clouds H and He||Solar winds||Clouds enriched in light elements|
|Reduced atomic variety||Progressive ignition star in strata||Variety of
|Collapse massive stars||Heart of incompressible degenerate matter||Shock wave supernovae: generation
|Interstellar clouds H and He||Confinement of neutrinos in heart before eviction||Enrichment interstellar environment
with assist shock wave and
|Binary massive||Explosion supernovae by fall gas on companion neutron star||Generation elements
Heavy and enrichment interstellar environment
|Grains silicates in interstellar clouds||Chemical reactions ion molecule||Apparition of organic molecules|
|Right and left amino acids||Solar winds and unveiling heart||Polarization amino acids by ultraviolet radiation: destroyed right amino acids|
|Stable clouds||Shock wave Supernovae||Generation of multiple sun nodules|
|Disc of accretion||Sun shock wave by eviction equatorial ring||Concentric rings asteroids|
|Cold zones of the discs of accretions||Condensation of snows of water||Forming of comets|
|Nucleus of helium||Resonant atomic nucleus in very reduced interval facilitating tunnel effect||Forming carbon by meeting of 3 pits of helium|
|Insufficient sun time of production for production aware life||Consumption reduced by fusion for pressure of radiation balancing peripheral layers||Stable sun over geologic periods|
|Association Hydrogène - oxygenates||Polarization electron on oxygen of the water molecule ( sensitization Hydrogenates)||Creation of the link hydrogenates: properties of the water: liquid water , solvency, hydration matter|
|Telluric planets without volatile materials||Fall comets by effect of sling on massive planets in the border of the cold wall||Forming oceans|
|Not differentiated telluric planets||Fusion core by diffusion of thermic shock due to comet and asteroid strikes on Earth||Differentiation core / coat|
|Global heart in cooling||Radioactive decomposition uranium||Preserves warm heart and volcanism|
|Global heart in cooling||Sufficientglobal mass to limit waste||Preservation volcanism and tectonics of patches|
|Risk of racing of the greenhouse effect||Stratospheric cold layer for waste surplus heat ( thermic machine)||Preservation of the oceans
( Opposition to Venus)
|Planets without magnetic field||Generation field by interaction coat / core||Protection against solar winds for life of surface|
|Primitive organic chemistry||Reducing degassing (NH4, NH3)
Contribution amino acids by meteorites
|Chemistry meadow oceanic biotick|
|Planets without differentiated crust||Fall comets||Contribution carbon and metals for forming continental crusts|
|Planets in risk glaciation||Contribution carbon comets||Atmosphere greenhouse effect|
|DisApparition of greenhouse effect by acid rains and formingcarbonates||Volcanism and restructuralisation carbon buried by owed subduction movement patches (interaction crust and coat)||Preservation greenhouse effect and compatible temperature liquid oceans|
|Planets with unstable axis of rotation||Shock massive celestial body and Earth||Forming of the Moon|
|Planets with weak interaction between oceans and border coastal||The Moon||Tides and contribution matter organic oceanic on coasts and bordering lakes|
|Planets with chemistry meadow biotick||Calcareous rocks with cavities for substratum||Forming chains ARN|
|Chain unprotected ARN||Integration in bubbles of the liquid environment(lakes)||Primitive cell|
|Cell RNA||Differentiation coding and mechanism of transcription||Cell DNA|
|Virus||Creation mitochondries and fusion with cell DNA||LUCA: cell DNA with active metabolism|
|Cell using only processes chemical as source of energy||Photosynthesis||Cellular proliferation by source solar energy|
|Cell without integrity for support coding||Creation of the cell nucleous||Eucaryotes|
|Inertial geochemical environment||Specialization and cellular productiviste||Bacteria (and Archeobacteria)|
|Slow genetic evolution||Creation of the complementarity||Sexuality and explosion of the alive|
|Floating and passive body||Creation central nervous system||Mobile body: fishes and nervous development by defence / attack: consciousness|
|Atmosphere without combustive at rate of high return||Rejection oxygenates by cyanobacteria, algae, plants||Oxygen for mobile organism: animals|
|Reproduction of the uncontrolled mutations||Decomposition oxygenates biatomic + triatomic reorganization ( high atmosphere)||Ozone layers defender of the hard UV radiation|
|Fire risk by atmosphere saturated by oxygen||Consumption oxygenates by bacteria + contribution nitrogen accumulated by degassing||Limitation of the rate of oxygen and preservation of the ground vegetable|
|Slow evolution||Triangle Sun in Mars Jupiter and fall asteroids and comets||Big disasters and new initialization of the alive|
|Slow evolution||Chaotic process in ground coat: periodic phase of massive volcanism||Big disasters and new initialization of the alive|
|Maritime animals||Tectonics of patches||Development ground and air life on continental crusts|
The Chain of the evolution
|Before: monocellular shape||At the end massive
PreCambrian: 650 millions
|Before: weak diversification||Explosion of the Cambrian
Invention dorsal column piccaia )
|440 millions||Massive extinction
Disappearance: 12 % families (maritimes)
|360 millions||Massive extinction
Disappearance: 14 % families (maritimes)
|Before: only maritime animals||Constitution of the continental crusts (Devonien 360 million years)||Insects and amphibians ( ichthyostega )|
|Before: only terrestrials reptiles||Permien (250 million years)||Mammals ( cynognathus )|
|At the end of the
|Massive extinction: disappearance 50 % families (little deep seas and earth)|
|210 millions||Massive extinction: disappearance: 12 % families (little deep seas) and 28 % (terrestrials)|
|Before: only plants with leaves||Cretaceous (130 million years)||Plants with flowers
and with fruits: social insects and reproduction small mammals
|64,4 mill.||Massive extinction:
disparition: 11 % (little deep seas and 14 % (terrestrials)
End of dinosaurs
|Before: terrestrials Mammalians||40 millions||Prosimians|
|38,37 and 32||Moderate extinction on impact massive meteorites|
|Before: homogeneity North-South of the temperatures the Atlantic Ocean||6 millions||Encirclement pole by continent: limitation traffic warm water: glaciation pole north|
|Before: impoverishment steppes and faunae (Africa, Amerique of the South, Australia)||5 millions||Volcanism African rift valley (unique ground fault to the world) and enrichment of lands|
|4,4 millions||Appearance australopithecus: sexual altruism ( domestic link) and exploitation food meat-based (bare monkey runner, neocerebral cortex developpment , slow extension feminine pond)|
|Before: dries steppes||2,5 million years||Central lock Amerique in conjunction with current cold Arctic: forming of GulfStream: rainfall tropical increased|
Homo Erectus (ancient world)
Neanderthalis (ancient world)
Homo Sapiens Sapiens (anc and new world)
|Massive extinction||20 000 years||Regression Gulf-Stream: glaciation and Extinction megafauna mammals|
|6th extinction||Modern era||Human extension
Intensification greenhouse effect
5.3.3 From the Moon to the Cosmos, the Whole and (almost) nothing
The existence of the life is the fact of a chain surprising fundamental forces which govern the physics what becomes a reality by an organization of the universe in all the scales which tends to return the possible sight.
Let us examine the facts with astronomical or astrophysical characters which have a wide impact on our existence.
We shall leave the most close and the most evident objects to raise gradually towards more abstract aspects.
A first surprising fact; the necessity of the Moon.
The Moon allows a stabilization of the Earth axis of rotation which seems to it necessary for an evolved life. The moon three or four times as small and it is all the ground climate which varies in a chaotic way (a world only populated with insects?).
The report of the masses of the Earth and the Moon reported at their distance and the importance of the engendered tides allowed the mixing of matter meadow biotick on the first continental banks .
If today the part of the Sun with regard to the Moon in the phenomenon of tides is 1 for 2, the Earth has its creation turned on itself it a dozen hour; the Moon was thus 2,4 times as close, their mutual attraction 6 times as big and the Sun counted only for a twelfth in the oceanic tides.
The model most usually admitted for the forming of the Moon in the composition appreciably different from that of the Earth is that it would be the result of a collision between the Earth and the celestial body of a dimension comparable to that of March. The Moon appreciably bigger would have been effectively able to be got by the Earth but the probability of a natural stabilization is weak and a collision of the Earth with a celestial body appreciably bigger would have been able to destroy it.
Besides there are limits of resistances of the fragile flora of the coast in the effects of tide engendered by the impressive Moon; even there the evolved life would have been in danger.
The Sun by its stability (4,5 billion years behind us and 1 in 2 billion bearable temperatures in front of us) by its distance, allows a coexistence of the water under its three forms (water, vapor and ice) on Earth the atmosphere of which makes us cross of one-23°C theoretical in 15°C on average thanks to her. The water in the form of vapor or of water is an evident necessity for the life such as we know it (and another type is only speculation chemically much less likely). But the ice?
One of the main interests of the ice is its regulation of the quantity of salt in the oceans: the oceans are more productive in phase of glaciation. These glaciations are due to the progressive disappearance of the CO 2 absorbed by carbonates and consecutive decrease of the greenhouse effect.
But to what what is due what the paleontologists call the explosion of the Cambrian that is the multicellular explosion of forms of life there is only 1 billion years later approximately 4 billion years of congestion; maybe in a bigger climatic variability and in variations of enrichment in calcium of the sea...
And Jupiter? Even if its direct gravitational influence seems weak, the major celestial body of the solar system seems to have been essential in the apparition of an intelligent life on Earth! Having prevented by effect of tide, the forming of a planet in approximately 300 million kilometres of the Earth, between Mars and Jupiter, a belt of asteroid took the place of this small missed planet. The phenomena of echos between Mars and Jupiter so allow the uncoupling of the asteroids of their orbits
It is evident that the biggest asteroids are the rarest but on the scale of millions or dozens million years, their collisions with the Earth gives sometimes new fondations for the evolution of the life by resetting the development of the sorts and by multiplying the attempts of complexity.
We also look for in the sky a big star which would have been able to cross our road, having upset the belt of asteroids to throw one or some on Earth here is 65 million years, finishing the extinction of dinosaurs besides already strongly begun (dinosaurs were in variety much less numerous than in the time of the maintaining famous Jurassic). This star could now be in several thousand years light, if we consider the relative speed of stars (statistically a star of magnitude 12 to 5000 Y-L ).
Stars are our gluttonous and furious grandmothers. If all the light elements up to the carbon can be expelled from the outside layers of the stars of average size during their final transformation novæ , the synthesis of the heavier elements so necessary for the life can be produced only by one supernovae which would have enriched the protosun nebula by provoking its forming by the shock wave of supernovae.
We also tried to find in our galactic arm the region where was one or several supernovae which presided over our birth.
Several generations of stars were thus needed to engender us. At least several short generations of supernovae of massive stars in the first phases of the Galaxy, these generations of massive stars lasting only some millions in some hundreds of million years, followed by at least a slow generation of more numerous stars which formed the intermediate chemical elements in rather big quantity (at least 5 billion years of duration). But the sun nebula has of to collapse further to the resultant shock wave of an explosion of close stars.
Do not we end in the model of a top of fertile stars, an endowed top arm which are places of density increased to provoke the progressive more and more complex enrichment in materials, step by step, on about 10 billion years? The Milky Way thus seems too necessary for our apparition.
But why the Cosmos has this density, why so many galaxies, is this necessary?
In a cosmos of 13 billion years the density is about 1 galaxy similar to ours every 20 million years - light. But the large-scale universe (300 million light years) seeming uniform, as also demonstrates it the cosmological, isotropic diffuse bottom, the smoothing of the fluctuations during Big-Bang would require a universe 10 times as massive as what the calculations of stability of the heap of galaxies allow to estimate .
In this logic, a going part from 90 to 99 % of the mass of the universe seems constituted by matter emitting excessively little or in no way of electromagnetic radiation.
From this initial mass we can deduct the proportion of the light elements generated by nuclear fusion during the first moments of the expanding universe .
The moderate proportion of the light elements of the hydrogen in the lithium implies a mass of the universe close to that necessities to explain the galactic stability of the heap and the shape of the galaxies in interaction. 10 % of the total mass would be thus visible.
This not visible mass is deducted from 3 main factors: a calculation balancing the kinetic energy of a heap and its energy of gravitation by considering a heap in dynamic balance.
It is deducted from the observation of galaxies in interaction.
It is also the result of the value of the mass of a not exotic matter, made by already known particles and which restores the densities of the fundamental elements produced during the initial explosion if we hold the likely hypothesis of Big-Bang.
Less hydrogen would have led to an impoverishment of the initial fuel of stars and to stars of shorter life expectancy.
More hydrogen would suppose from the beginning less heavy elements to catalyse, facilitate the fusion and thus generations of longer stars.
But the debate remains opened on the necessary rate to constitute sun nebulas in the proportions in elements similar to ours.
It seems that the dimensions of a Universe allowing the life could hardly be different from those whom we notice.
Let us examine at the moment the fundamental forces which impact the balance of the Cosmos
The existence of the chemical reactions depends very strongly of the electromagnetic " constant of coupling " , which corresponds chargeable to the electron. If this value was slightly modified, for example by increasing it, the distance between electrons and the pits would be reduced and the reactions will ask for more energy what will reduce the probability that form complex structures. Any important variation becomes catastrophic.
Any reduction will also have the effect of making very sensitive compose them chemical in the breaks of connection preventing the forming of complex shape.
An essential impact is for example the disappearance of the efficiency of the water as the solvent; its triatomic form with a 105 degree angle between the connections O-H being fundamental so that it keeps its properties ( liquid water and viscosity, notably). Without a water with these properties, no possible life.
The life would not be possible without the existence and the preservation of stars on a long duration.
Stars are battlefields where are in confrontation 4 forces.
Stars continue because they are the product of a balance between the gravitation and the pressure interns engendered by the electromagnetic forces of the plasma.
This pressure is due to the thermic excitement of nucleus and electrons, excitement fed by the nuclear fusion.
This one results from a subtle effect of the weak force which transforms the neutrons into protons and the strong force which agglutinates protons and neutrons to form pits. The level difference of energy between these separate and gathered nucleus is transformed into photons and into neutrinos.
Now a small difference between the parameters which control the intensity of these forces and the notion of stars would disappear or in best the intensity and the duration of their brilliance would become incompatible of the duration of evolution of the alive and its need in energy.
A subtle effect is for example the generation of the carbon indispensable to the alive from the helium in stars. Now the carbon results from the simultaneous and thus improbable meeting of three pits of helium. To allow a significant production of carbon pits have to be for certain very precise levels of energy which correspond to echos between quantum numbers. Certain echos amplify considerably the quicknesses of reaction and assure the fusion of 3 pits before their excitement separates them. Fred Hoyle who has studies the phenomenon has calculates a certain resonance perfectly adapts to the energy of the helium in the massive stars.
This resonance was confirmed only then experimentally.
Fred Hoyle qualified the Universe " as put-up job ".
The mystery of the neutrino.
The neutrino is produced during the fusions and the transformation of a proton in neutron.
This neutrino is almost undetectable.
The heavy bodies: 1057 Neutrinos for a 2nd breath of Supernovae
The origin of the matter: the strong force
The report between the forces of gravitation and the electric forces seems to indicate that the gravitation is the product of the whole observed universe and that the electric force is only the product of the bearer of load where from an exactly inverse report between 2 forces (2x10 39 ) And the report of the size of the universe on the size of the elementary bearer ( the proton). The proton having a size of the order of 1013 We find a size of the universe of 20 billion light years.
In view of all this chain, an evidence is imperative.
The Man, a fate not so fortuitous...
The previous history of the alive The Research except series in February 99
The cosmic previous history of the life Armand Delsemme Champs Flammarion
Le Monde Column Horizons 5/8/99
Logical depth and Complexity Science and life in May, 1999