The importance of earth’s axis tilt

The scientific consensus on the fact that in the last century human activities began to cause a warming climate is now widespread even among the general public.
The industrial companies have begun to spread into the atmosphere carbon dioxide and other greenhouse gases with the introduction of manufacturing plants and coal-fired power stations, whose emissions are then added to those of motor vehicles. In those circumstances, only who lived in the industrial sector is responsible for the accumulation of greenhouse gases into the atmosphere and for the trend towards global warming?
Things are not really so. Certainly the industrial activities have contributed greatly, but there are other natural factors that influence the climate.
Since the seventies is recognised that what dominate the global climate is the long term (by millions of years) three variations of the Earth rotation around the Sun called Milankovich cycles.


The precession of the equinoxes is a gradual shift of the Earth's rotation axis. This motion is caused secondary by the gravity attraction of the Moon and the Sun that tends to change the direction of them and describe, clockwise, the surface of a cone in little more than 23000 years.


Tilt: the angle of the Earth's axis relative to the plane of its orbit varies between 21.5 and 24.5 degrees over a period of 41,000 years...



Eccentricity: the shape of the Earth's orbit around the Sun. The eccentricity varies over about 100,000 years between slightly more or less elliptical.

As a result of these orbital cycles the amount of solar radiation reaching the various parts of the globe in a given season, can vary by more than ten percent. Over the past three million years, these changes in the amount of sunlight that reached the surface of the planet have produced a long sequence of glaciations separated by brief warmer periods.
While it revolves around its axis, Earth waves as a gyroscope.
A carrot ice recovered three kilometers long in the nineties of the last century from the Vostok station in Antarctica contained ancient air bubbles that revealed the composition of the atmosphere in the last eight hundred thousand years.
The natural variations of earth’s orbit change the sunlight that reaches the globe and cause strong fluctuations in atmospheric concentrations of methane and carbon dioxide.
The Vostok cores tell us that concentrations of methane into the atmosphere have increased and decreased in the last three hundred and fifty thousand years, in perfect harmony with the ups and downs of solar radiation, induced by precession in the north.
Concentrations of carbon dioxide are varied depending on the precession, the variation of the tilt of Earth's rotation and orbital shape of the planet. These cycles occur every 41000 and 11000 years. For reasons still not entirely clear, global concentrations of these greenhouse gases cause almost exclusively changes that occur during the summer in the northern hemisphere, where focuses most of the continental masses. The peak of summer heat in the northern occur every twenty-two thousand years, when the northern summer coincides with the Earth’s moving closer to the Sun and the northern hemisphere receives the maximum light. The summer heat instead reaches the minimum eleven thousand years later, after the Earth's axis has made half a revolution. The hemisphere receives the least sunlight summer because the Earth and the Sun are at the maximum distance.
In summary, cores of Vostok tell us that despite the wide fluctuations had in the past, the climate has maintained a regularity that reflected changes into that of Earth’s orbit, ranging between two stages of apparent balance, a cold glacial period and another warm period. This has happened in the last eight hundred thousand years.
Today, however, is no longer so, in fact the human activities have changed forever the natural cycles and, with a certainty, our impact on the environment will grow more and more. We can not go back. We can, however, studying the transformation process in place, learn to control it and groped handle with the choices of politics and with the laws of physics. People will say, what has it got to do to with physics? Physics have to do a lot!


Summary of Milankovich cycles…

The greenhouse effect

The dayly average intensity of solar radiation that reaches the earth is 1372 watts per square metre. The Earth spins on its axis and distributes on average over the year this amount of energy (equivalent to 343 watts/m2) on every square meter of its surface and in the high layers of the atmosphere. Thirty per cent of this flow of energy is reflected directly in space. The remainder is absorbed and, after having contributed to the climate, is re-radiated in the form of infrared energy. Among the factors affecting the climate of our planet, the most important is certainly the slope of the earth’s orbit respect to the Ecliptic plane. Because of this in a certain period the northern hemisphere is more exposed to the sun. Six months later, the southern hemisphere is more exposed to the sun.
The atmosphere is composed primarily of nitrogen, oxygen and in lesser quantities from other gases. The light coming from the sun crosses it easily and that part not reflected by ice or clouds illuminates and warms the surface.
The heat is accumulated, subsequently reissued from Earth in the form of infrared rays which are partly reflected back toward Earth and in part to space.
The gases that contribute further to reflect in part to the Earth energy re-radiated by the Earth itself are the water vapor, ozone, chlorofluorocarbons, nitrogen oxides, methane and especially carbon dioxide, namely greenhouse gases. Without the presence of these gases throughout which the infrared energy would be reflected in space, the average temperature of the planet would be around -20 degrees centigrade, impossible for life.
Instead, the presence of greenhouse gases into the atmosphere allow to intercept about 70 percent of infrared radiation re-emitted from Earth, causing rising temperatures average around 14 degrees centigrade.
To understand the nature and significance of the greenhouse effect is necessary to examine in more detail what is the energy balance in the global climate system. The main source of energy, but also unique, given the negligible influence of other sources of energy from space or from underground, is the Sun. The sun emits a flow of energy form of electromagnetic radiation, equal to about 64 million of watt/m2 (watts per square meter) at a temperature of about 56 thousand ° C. This energy is dispersed evenly in space in all directions. On Earth, which is about 150 million km from the sun, only a fraction extremely small of theinitial flow reaches, which amounted to about 0.002 per thousand. However, this flow of energy would reach fully to the ground if the Earth was flat and was exactly perpendicular to sunlight and, moreover, had not come any means, as the atmosphere, which mitigates and disseminates the solar radiation. Instead, the Earth is spherical and sunlight come, perpendicular or slightly tilted, at low latitudes (zone intertropicale), but gradually more and more inclined to high latitudes, and this causes an uneven distribution of solar flux between equatorial zones and Polar zones. In addition, the Earth rotates on itself and rotates around the sun, and this causes a further uneven distribution of solar radiation between day and night and between one season and another.
All these fluctuations are, however, cyclical and are repeated regularly with daily and annual basis.
If we take as a reference the calendar year, the average annual solar energy that would reach the surface, if there were no atmosphere, would amount at 343 watt/m2. This energy flow is the maximum average value of solar energy per unit area, which our planet can theoretically have.
The flow of energy actually used by our planet is, however, less because the Earth is not a surface "black" (it not totally absorb the incoming solar radiation) but has areas composed of soil, rocks, seas and oceans, who have a certain reflectivity (called albedo). The average albedo of the earth is equal to 30%. Therefore, the flow of average energy of solar radiation actually used by our planet as a source of energy is 240 watt/m2.
This energy we have would enable our planet, if there were no atmosphere, to reach a maximum mean temperature of 20 ° C below zero.
The temperature ranges around this average would, however, very high between polar and equatorial zones between night and day and between summer and winter.
Once the solar radiation has come on the Earth's surface, it is absorbed by soil and seas, which are increasing their warm temperature. As it gradually increases the temperature, the Earth's surface emits energy in the form of heat and, in other words, as infrared radiation, until it establishes a balance between flow of solar energy incident and flow of Earth's energy outgoing to the space.
We have seen before that if there were no atmosphere, the average temperature of our planet would be almost 20 ° C below zero. Instead, thanks to the presence of the atmosphere, the average temperature reaches almost 14 ° C above zero. Then, the earth's atmosphere with its content of greenhouse gases raise global average of over 34 ° C.
But the most important thing to emphasise is that, while the temperature of 20 ° C below zero would reaches with a stream of solar energy of 240 watt/m2, as we have seen before, the temperature of 14 ° C above zero that occurs with the presence of the atmosphere, vice versa is reached with a stream of solar energy lower, namely with about 170 watt/m2, a value that is half the maximum available (343 watt/m2).
The reason for that, on the ground, in the presence of atmosphere, the surface get a flow less energy compared to the absence of atmosphere, comes from loss of energy that solar radiation suffer while entering in the increasingly dense layers of the atmosphere. The losses (102 watt/m2) are both caused by the reflection of sunlight to the space by the clouds, and by its dispersion and spread into the atmosphere of the solar radiation, part of which returns to space.
The cause for that, on the ground, with an energy flow slower compared to case of the absence of atmosphere, temperatures of over 34 ° C are reached, depends on the ability to store heat in the atmosphere: this capacity is called "greenhouse effect"…
The atmosphere is a mixture of gases that owns a characteristic property (with clean air and clear from clouds): it is transparent to radiation from the Sun, but it is opaque to infrared radiation reflected from Earth, because of the presence of certain gases such as the water vapor and carbon dioxide that are strong absorbers and emitting of infrared radiation. But when carbon dioxide differs from the rates naturally present in the atmosphere, things are more complicated. Let's see how.
The greenhouse effect involves the Earth, with the land, oceans and atmosphere. Among them there is a balance heat and thus energy which also involves the space: the amount of energy absorbed should be equal to that re-emitted. The thermodynamics not escape. So it is.
The increased concentration of carbon dioxide caused by human activity traps more infrared energy that increases the temperature of the atmosphere. This increase leads to greater evaporation of water from the oceans. The water vapor is, in turn, a powerful greenhouse gas that contributes to retain the infrared radiation facilitating overheating from Earth. The increase heat leads to the dissolution of the polar caps and, consequently, reduces the surface reflecting the light radiation from the sun causing a further rise in temperature of the planet.
At the same time also increases the condensation of water vapor that turns into clouds that reflect light from the Sun that decreases the radiation absorbed by the planet, and thus temperature.
But the melting ice cancel out the effect of the gulf current, concomitant mild European climate, causing a small ice age in part of central and northern Russia. They form so again a wide air ice that reflect the light radiation in space.
The thermodynamic equilibrium is re-estabilshed forever...
In about two hundred years from start of the industrial age, we have increased by almost 40 per cent carbon dioxide in the atmosphere and, more time passes, more we globalize industrial activities and more it increases.
The increase of carbon dioxide creates a problem, a big and serious problem: intercepted infrared energy is greater and this causes the increase of average temperature of the planet.
Already today the modest increase in temperature that was recorded is reflected on climate change with consequences sometimes dramatic.
The increased energy of the atmosphere active extreme increasingly disruptive phenomena because the natural climate balance is, in part, already upset.
The polar caps are melting and the Ecotone, located at the southern Central Massif of France is shifting (the Ecotono is a boundary between two or more ecological zones where the vegetation changes from a distance of a few metres, in this case vegetation typical of temperate areas to that of Mediterranean scrub).
The Tropical Convergence Zone is always less stable and monsoon that governs rains are increasingly less predictable in duration, intensity and areas where they act. Another problem is El Nino. The Southern Oscillation that it activates, which is a swing of the values of atmospheric pressure between the eastern and equatorial Pacific, is increasingly unpredictably in intensity and duration.
So, working to switch from oil to other sources of energy and study and propose solutions that can give us forecasts on climate change is fundamental to reduce our vulnerability from predictable extreme events that may occur.

A little bit more of astronomy

There are two main movements of the Earth. That rotation and the revolution. The rotation is the movement of the Earth around its axis. An entire rotation takes about 24 hours. At any time of 24 hours there is a half sphere of the earth that receives the light of the Sun and another half which is surrounded by the night. The line that separates the dark half side of the Earth by the half illuminated side and that moves as the Earth rotates is called the circle of illumination. The revolution is the movement that makes the Earth traveling along its orbit around the Sun with a speed of more than 107.000 km / h along an elliptical orbit. The distance between the Earth and the Sun is on average 150 million km; "average" because, since the Earth's orbit is slightly elliptical, this distance varies throughout the year. In (around) January 3 our planet is located to its minimum distance from the Sun, about 147 million kilometres, in the position called perihelion; about six months later, around July 4, the Earth is at its maximum distance from the Sun, about 152 million of kilometers, in the position called aphelion. Variations in the amount of solar energy received from the Earth due to these small changes in distance are very limited and have minimal consequences in the context of much greater seasonal variations in temperature: for example, the Earth is closest to sun when in our own hemisphere, the northern one, is winter.
When the Sun is exactly on the vertical of a given area its rays do a route least equal to the thickness of the atmosphere, when on other hand, are tilted of 30 degrees, they walk into a route twice that minimum, and, when they are inclined of 5 degrees, their journey through the atmosphere is eleven times greater. So, the longer the journey of solar radiation through the atmosphere is, the greater the chance that they will be absorbed, reflected and scattered, and the more the intensity of radiation reaching the earth's surface is reduced.
The Earth, let us not forget, is spherical, so every day the rays of sun at midday vertical fall only on points of the earth's surface that are located in a particular latitude, as we move northward or southward over that latitude, the sun's rays affect the Earth's surface with corners gradually smallers. In addition, the inclination of the sun's rays at a certain latitude varies throughout the year, because the orientation of the Earth: in fact, the sun is not perpendicular to the planeof earth’s orbit (if it were, as now we will see, changes of season would not be) but is 23.27 degrees inclined from the perpendicular. Moreover, since during the movement of revolution of the Earth around the Sun the direction of earth does not change (the axis move parallel to himself, always pointing toward the polar star), the orientation of the latter compared to sunlight change in the various periods of the year.
There is one day in a year where the the northern hemisphere is 23.27 degrees "inclined" towards the Sun; six months later, when the Earth has reached exactly the opposite position along the orbit, the northern hemisphere is 23.27 degrees "inclined" in the opposite direction to the Sun. In the days between these two extreme situations, the Earth's axis is tilted less than 23.27 degrees compared to sunlight.
This periodic change of orientation of the Earth than the sun makes the area on which the rays of sun at midday fall vertically to move annually between 23.27 degrees north of equator and 23.27 degrees south of it. As a result, in many places the maximum height of the Sun in the sky (which is at noon) varies during the year, almost 47 degrees (ie 23.27 degrees + 23.27 degrees). This " annual migration" of the rays of the sun have effects of such migration on the annual cycle of weather conditions, which cause the various seasons. On June 21 the Earth is in a position where its northern hemisphere is directed towards the Sun, with an inclination of 23.27 degrees. At this date, at noon, the rays of the sun are perpendicular to the areas located at 23,27 degrees north latitude, which is a parallel of the Earth called Tropic of Cancer. For those who live in the northern hemisphere on June 21 is the summer solstice. Six months later, on December 21, the Earth is in a position opposite to the previous and rays of sun at midday are perpendicular to the areas located at 23.27 degrees latitude south, which corresponds to a parallel of the Earth called Tropic of Capricorn. For those who live in the northern hemisphere on December 21 is the winter solstice. On the same day in the southern hemisphere occurs the opposite situation, you namely have the summer solstice. Halfway between the two solstices fall equinoxes: in September 22 in the northern hemisphere you have the autumn equinox, in March 21 the spring equinox (the opposite happens in the southern hemisphere). In those days, at noon, the rays of the sun are perpendicular to the equator (0 degrees latitude) and tangent to the poles, because along its orbit the Earth is in a position that the Earth's axis is not inclined either to the Sun, nor in the opposite direction to it.

The earthquakes and the displacement of the Earth’s rotation axis

All the scenarios on global warming identified by scientists before the Paris conference included a pace of global warming and melting of glaciers slower. The new data tell us, however, that climate change is a threat bigger and closer than first thought not. So we must act immediately, trying to "cool down" the Earth. How? Simple, by changing the tilt of the Earth's rotation. People will say: this man is crazy! Be quiet, calm, and let’s reflect on two phenomena.
The drift of sliding continents determines the depth of oceanic plates that affects the orbit and the rotation of Earth, with swings and variations of the rotation axis, which determines a different angle of incidence of sunlight on the surface Land, and a change in position and intensity of the earth's magnetic field (which protects us from cosmic rays).
The earthquake of 26 December 2004 ( 9 degrees Richter ) off the coast of Sumatra has shifted the Earth's axis. Already we knew that an earthquake of magnitude exceeding 8 degrees puts in motion a quantity of energy such as to alter the distribution of masses on the Earth's crust and thus is able to move the Earth's axis.
But until now never happened that this could be observed instrumentally. It was exactly 40 years that the Earth was not affected by a similar telluric movement and in 1964, the year of the great earthquake, there were not yet so sophisticated instruments to assess the movement.
One of the main italian newspapers, the “Corriere della Sera”, after the earthquake in Sumatra, interviewed Professor Bianco, director of the Center space geodesy of Italian Space Agency (Asi) in Matera, who said that "according to surveys made by satellites Lageos 1 and Lageos 2, the Earth's axis has shifted to 2 thousandths of a second of arc corresponding to a linear displacement of 5-6 centimeters. The shift has occurred precisely along the direction of the earthquake epicentre, near to the equator. So it has not changed the angle of axis (which is approximately 23 degrees and a half), but the direction towards which the axis tip in space.
The change in the angle of the rotation, in general, can alter the climate. In fact, the alternation of seasons depends precisely by the fact that the axis is tilted. If it were perfectly vertical, the poles would be almost always dark and cold, while the equatorial regions and tropical would receive much more solar radiation and temperatures were far superior to current ones.
So if the angle was less of the current 23.27 °, would be colder at high latitudes and warmer at the equator, instead if it was more than 23.27 °C, the poles would receive more sun and the ice caps would risk dissolution.
The fact that the angle of rotation has not changed, but only moved sideways reassures us, but not entirely if we look at the data in the recent past.
Eight of the ten strongest earthquakes of the last century have occurred in a time very limited: only 15 years.
From August 15, 1950 the aftershocks above 8.5 degrees were eight, including four of more than 9 degrees .. All have occurred in India and circumpacifica. We are therefore at the beginning of a new seismic phase that could last 15-20 years? Maybe, there are no elements to say. But if in the coming years will occur in the same way other macro earthquakes of great intensity, then one might find in the same situation of the fifties - sixties.
But what about the climate change if the Earth's axis with the earthquake in Sumatra has not changed the angle vertical?
If earthquakes grade exceeding 8 are able to move the Earth's axis, surely this has been done even during the years seismic'50-'60, which were also more strong and violent. Even in that period moving Axis has happened only horizontally and did not change the angle? We do not know, there were no instruments capable of accurately measured.
But we know with certainty that in correspondence of those years the temperature was colder than today, especially at high latitudes, with a drop of up to 0.4 ° C compared to the nowday average. After that the average temperature has risen up to the highest levels of the century in recent years. The average temperature depends on many factors: greenhouse gases, solar phases, presence of dust in the upper atmosphere due to large eruptions, inclination of the earth axis.
The cold phase of the fifties - Sixty may have been due to a combination of these factors, to which may have contributed large earthquakes. Contribution modest but noticeable.
So the recurrence of violent seismic events could have consequences on climate change, albeit in limited numbers for a short period of time. We only hope, with also the contribution of science and technology, that future earthquakes act on the earth so that this decrease its angle so as to trigger a period colder and save for a few years the polar caps, to allow our politicians to come to their senses. If the angle were to increase, the catastrophic consequences due to melting of glaciers will occur at a rate even higher than today, with damage whose enormity is unpredictable. Well, you can say that I’m crazy, but we certainly can not hope that the telluric cataclysms move the axis terrestrial in a random way, or wait for the very slow phenomena induced by continental drift, what do you think?

Some solutions

So given that there is no intention to change the economic model that is the cause of global environmental disaster that generates the greenhouse effect, pending that grow the cultural sensitivity necessary to face, globally and in all its components, the planetary problem of pollution, we must do something, a simple thing: reduce the effect of the impact on global warming energy coming from space, from the Sun. And you can do that in only two ways, or putting between the Sun and Earth some enormous parasol umbrellas being able to intercept the solar radiation that arrives on the planet or tilting the Earth's axis so as to decrease in both hemispheres the energy of sunlight.
There is a point in space where a body could be put into an orbit around the Sun without this being attracted by the force of gravity of our star. A mega umbrella made at that point, at the right orbital velocity (easily calculable with Kepler's laws) would remain quietly in that orbit, in front of our planet, because at that distance the force of terrestrial gravity compensates exactly that of the Sun.

This point, known as langrangian point is on the line joining the centre of the Earth with the centre of the Sun and is about 15 million kilometres from our planet. This umbrella, at that distance, to have the effect of significantly reduce the incoming solar radiation on Earth, it must have a diameter of at least 4 thousand kilometers. Another option to prevent the solar radiation reaching the earth could be to draw the asteroid of the appropriate size from the belt of asteroids and to place it at the lagrangian point...or it could explode (in a controlled way) so that the dust created as a result of explosion can intercept the solar radiation.

Too complicated and science-fiction? Less than at first glance it may seem, today we have the technologies needed. After all when it comes to "explode" something the men are unbeatable.
Imagine what technological effort and especially how much time would be needed to implement similar projects. And we do not have time.
And then it remains only the other solution, to change the tilt of the rotation axis of the Earth.

Let’s refresh a little our memory.
The greenhouse effect we have previously said is the phenomenon whereby the energy emitted from the Earth to space (mainly as infrared radiation), to balance the flow of energy received from the Sun, is partially absorbed by some gas present in atmosphere and from these radiated again toward the Earth.
In this way once delayed dispersal of energy creates an average temperature on the surface greater than that which would occur in the absence of atmosphere. The temperature on the surface of a planet depends on the balance between energy received from other celestial bodies and energy that radiates to space. Then, a balance is determined. In this process energy determines a balance between the composition and the amount of solar radiation received by the Earth and that emitted by the earth in the space, balance that defines the average temperature on Earth's surface, fundamental to take place of life on our planet. If you change one of the factors at play the balance moves. In the specific case there is alarm for the significant increase of carbon dioxide. At present the atmosphere contains 380 parts per million (ppm) of carbon dioxide compared with 280 ppm of the pre-industrial age. To ensure that the global average temperature does not increase beyond two degrees the concentration of carbon dioxide should not exceed 450 ppm. This goal will be impossible to achieve because today is expected to reach 400 ppm of carbon dioxide into the atmosphere over the next 10 years. We must accept this reality? The goal of maintaining the concentration below 450 ppm is not realistic.

This means that we are about to reach a point of no return where the changes could become irreversible. . The natural balance of the Earth heat is permanently altering; the collapse of the planet is near… And irreversible means no return, and we have to be afraid.
We have also seen previously that when the planet is in aphelion, that is the maximum distance from the Sun (152 million km around) we are in July, the hottest month in the northern hemisphere, the minimum distance from the Sun (147 million km ), We are instead in perielio in early January, the coldest month of the year.
What matters, remember it, is only the tilt of the Earth’s axis.
The solstice and the equinox correspond to important positions that the Earth assumes than the Sun in four different times in the calendar (in a year occur, in fact, two equinoxes and solstices two).
When the Earth is at equinox the sun's rays are perpendicular to the equator and kickbacks at the poles. As already mentioned, the temperature of the planet depends from the incidence between the area and rays of the sun: If these are perpendicular, they transport the maximum of energy, it is therefore evident that the heating has higher values to 0 ° latitude, namely the equator, it will have average values for medium latitudes and minimum at the poles.
The equinoxes give beginning, as their name indicates, to the seasons of spring and autumn, which concluded respectively with summer and winter solstices, when the relative seasons start.
The summer solstice occurs on June 21. On this date the rays of the sun are perpendicular to the Tropic of Cancer. So there’s a greater intensity warming in the boreal, our latitudes, where summer begins.
On the contrary, in the Southern Hemisphere begins winter because the duration of daily illumination reaches its minimum value. In the winter solstice the summer start in the austral hemisphere and in northern hemisphere is the day with fewest hours of light.
To return to us, we have two parameters on which to think about: the unstoppable emissions of carbon dioxide and energy that activates the greenhouse effect, the sunlight. As for the time being impossible to reduce emissions of carbon dioxide we have to ensure that the energy of sunlight affect as little as possible on global warming, forcing the rays of sunlight to make a longer way, to cross, that is, more time than natural, a greater amount of atmosphere in the southern hemisphere than in the north. How? By holding for a time to define the Earth in its equinoxes position, when the sun's rays are perpendicular to the equator and tangents to the poles. Or rather, straighten the axis of rotation in order to have a condition of solar radiation as the equinoxes. In this position the Earth at the poles would receive a minimum amount of energy, glaciers would not melt, ocean waters would warm the Equator and would set again exchanges cold-hot that feed the ocean currents and weather. Obviously other positions of the Earth than those assumed at equinoxes correspond to different inclinations of the Earth's axis of rotation that could cause a different distribution of carbon dioxide in the atmosphere with a transfer of it from northern emisphere to the south, "racking" that today is prevented by the "thermal equatorial barrier".
A greater inclination of the land would not prevent life on Earth. Probably it only would make a little 'more uncomfortable. It depends what you tilt. Meanwhile let’s ask ourselves: can we change the tilt of axis around which our beloved Earth turns? The desperation makes me say yes. I love life, I love lives. I love our planet, the one to life. And let us continue to be that place where the universe has generated himself to have awareness of self. And the place, Earth, where the infinite inanimate acquires and becomes awareness. And that’s what we are.

THE ATLAS PROJECT: the provocation?

What is the Earth? A sphere that almost always turns on its axis and that move around the sun. For the purposes of our reasoning, for simplicity, let’s consider the shape of Earth as a perfect sphere that rotates on its axis. What would happen if on a sphere rotating on its axis is applied a moment of forces direct into a general direction?
The overall effect will be to a change in speed ball and / or inclination of Axis of rotation. Will depend on the side surface of the sphere which will apply the moment of forces.
If such forces is applied so that its result is parallel to the rotation, in this case only vary the speed of rotation of the sphere.
Conversely, if the result of the moment of forces formed a certain angle with the axis of rotation, you have the either the inclination of a of the rotation ball axis either a change in its speed of rotation. And again, if the result of the moment of forces were applied orthogonal to the axis of rotation, we would have a sole effect, the tilt of the rotation axis. And this is not a fantasy, Physics says it.
The movement of bodies in rotation is governed by the second law of dynamics applied to extended bodies, which is:

M = L '

the apex ' is to indicate the derivative (ie the change) compared to time. This equation means that the sum of moments of external forces M causes a proportional variation of angular momentum L. In this equation all sizes, except the moment of inertia I, are magnitudes vector, that is equipped with intensity (form), to and direction.
In a sphere that rotates around a particular axis (the main axis of inertia), the angular momentum L is parallel to the rotation and has a magnitude that is equal to Iw.

-- I is the moment of inertia and its value depends on the mass of the body and how this mass is distributed around the axis of rotation. It expresses the "resistance" of the body to a rotation. For a sphere of mass m, radius R, the moment of inertia applies 3/5mR2.

-- w is the angular velocity in radians per second and measure the angle that is covered by the rotation of the body in a second.

Imagine having a homogeneous sphere that rotates but not traslate around an axis, without having to act any moment of forces: in this case its angular momentum L is constant, and thus the sphere rotate with constant angular velocity. (drawings by ing. Joseph Marino, from Savoia di Lucania)

ball that spins around its axis with a constant angular velocity, w


At a certain time we apply a moment of M. If M is parallel or antiparallel to L, the only change that will be is a change in the magnitude of vector L, so the ball will continue to rotate around the same axis but w will change in magnitude, namely related to the the Earth it mean that the days are longer or shorter depending on the angular velocity decreases or increases).

on the ball a moment of forces parallel …




and / or antiparallel to axis of rotation is determined, in which case not vary the tilt of the rotation but his angular velocity, w


If M is perpendicular to L there is a constant rotation of the direction of L and thus of the rotation, without change of the magnitude of angular momentum, so the angular velocity around the rotation axis will remain the same, but the axis will no longer be in the starting position (the Earth would continue to have the same length of day of today but with hours of light of different duration and also would vary the impact of solar heating, and this will depend on what is the inclination of varied axis of rotation).


on the ball rotation a moment M of forces orthogonal to the axis of rotation is determined …




…which cause the tilt of the rotation axis around which the ball continues to spin with the same angular velocity w

For inclinations of M compared to L intermediate to the previous cases, you have a combined effect of variation of the rotation angle and of angular velocity, since the component of M parallel to L cause changes in the magnitude of w, while the orthogonal component to L a change of direction of rotation Axis (on Earth would change both the duration of the day that daylight hours of the concerned emisphere and therefore the impact of global warming due to sunlight).


if the momentum M of forces applies on the intermediate surface of the sphere, so that forming a certain generic angle with the axis of rotation…



its components act simultaneously, determining an inclination of the rotation axis and a change in angular velocity w

When the moment of forces ceases to act, the angular momentum remains unchanged in magnitude and direction and the ball (and then the Earth) will remain to rotate around an axis different from that of departure. The starting assumption was that on the sphere external forces act, and this, related to the the Earth, would mean that those forces must necessarily come from space. Question, we must hope that a giant meteorite impacts with the Earth and cause the displacement of the earth? But neither in your dreams! We have seen first as the earthquake in Sumatra has produced a variation of the inclination of rotation axis of the Earth.
A change in the distribution of masses produced by the earthquake has changed the moment of inertia. But L must remain constant, not acting on Earth any external force. Since L = Iw , the effect of the change of I was offset by the change of w in magnitude and to and including removal of axis of rotation. An equivalent interpretation of the phenomenon can be given in terms of interactions between subsystems. Let me explain better.
In any Cabinet of physics of scientific schools you can do a little experiment. Take a rotating stool. Let sit on this stool a student who supports a bicycle wheel in motion with some speed. After the student rotate 180 ° the axis of the wheel.(drawings by Angelica Caggianese, from Savoia di Lucania)



What happens? The student and the stool (which were until then still) take a turn with a certain speed. What happened? Since the system (student stool) + wheel is isolated, namely M of external forces = 0, follows that system L = constant. Since then L system must be unchanged after the wheel was overturned on, the student stool turns in the opposite direction towards the rotation of the wheel (and at speeds twice that of wheel) to compensate for the variation of L system induced by this one.
The phenomenon can be analyzed in an equivalent manner even splitting the system (student stool) + wheel in two subsystems: (student stool) and wheel. The two subsystems are not isolated. The student, in turn axis of the wheel, holding a moment of Ms force on the wheel, and for the principle of action and reaction, the wheel exerts a moment Mr, equal and opposite on the student, forcing it to rotate. Ms and Mr moments are considered external, that is produced by a subsystem on the other.
Question: if the student was in rotation on the stool and instead of bicycle wheel had a rotating flywheel (in this case consists of a mass-shaped metal ring, in fact, a gyro) rotating around an axis perpendicular to the system student stool and, suddenly, with his hands the student activated the brake abruptly to block the rotation of badminton, what would happen? The system student stool would continue to turn but the student would no longer be sitting comfortably, but tilted.
The magnitude of angular momentum would not change (the system would continue to rotate as the first with the same speed) but would change the direction of which continues to rotate because this would in the meantime changed its initial position, sloping. The system student stool is equivalent to a sphere in rotation. Certainly a sphere with uneven mass, but the principle is the same.
The Earth planet is not a perfect sphere but a geoide, with a difference of about 45 km diameter measured between the equator and that measured at the poles. The Earth also consists of a thin crust and a huge mass "pasty." In the event of impact with an asteroid significant in scale, after the enormous destruction that would follow, there would be over time the effect produced by the new position available under Earth's tilt. If the Earth were a rigid moving mass the precession movement of its axis would take it back, over time, in its initial position. Our planet has an uneven nor rigid mass, and once the location of its axis of rotation varied, it tend to remain in the new conditions. Whatever artifice put in by man to change the angle of inclination of the Earth's rotation should reckon with an experimental stage, the computer simulation. This is because the laws of dynamics that we know refer to bodies with mass homogeneous. It 'true that the Earth's crust is very thin and therefore size negligible compared to internal dimensions of the planet, yet because of the "viscosity" of the inner mass, a simulation must be done. This is because we can not calculate easily as the laws of dynamic acting on a ball rolling mass smooth and uneven. Not only that, the simulation should take into account that the Earth is a "ball" that not only rotates on itself but is also subject to translation and that interacts with the gravity system of the Sun and the Moon. Then the simulation should take this into consideration, especially the Moon has so much influence on the stability of Earth's rotation.
In fact, the gravitational force of the moon stabilizes the slope of the earth, which varies by only 1.3 degrees around a mean value of 23.3 degrees.
Thanks to the stabilizing of the Moon, even catastrophic events such as the impact of our planet with a large meteorite could not move the Earth's axis: could be that only an impact with a body of almost planetary dimensions.
People will say: but then the axis will move or not? Be patient, move, move!
We have said that the Earth is a sphere that almost always turns on its axis and that traslate around the sun.
What would happen if on a sphere rotating on its axis is applied a moment of forces direct into a general direction? And above all, how do you create a moment of forces that generate such a strong result that they can affect the direction of rotation, rotation speed, or both simultaneously? We said that if this time the forces applied so that its results were parallel to the rotation, in this case only vary the speed of rotation of the sphere (in technical terms only the magnitude of  vary). Conversely, if the result of the momentum of forces form an angle with the axis of rotation, it cause either the inclination of the rotation axis of the ball either a change in its speed of rotation.
And again, if the moment of forces were applied orthogonal to the axis of rotation, we would simply tilt the angle of the rotation, as already mentioned above. All this means that if we apply the forces artificially on the surface of the Earth, depending on where it realizes, we have a variation in the speed of rotation, the variation of the inclination of earth’s axis or both phenomena. You can create the moment by putting loads of vehicles on a large surface in the shape of the circle (comparable to "flyweel" in rotation in the experiment of the student stool + flyweel mentioned above). There are so many camions and tir and if necessary the worldwide car industry would be able to build the right number in a very short period of time. Once in motion “the flywheel tir" acquire an angular momentum directly proportional to the speed with which moves and the moment of inertia I determined by the mass of vehicles (which is known) and their distance from the centre of the "flywheel" . This angular momentum would be transferred to Earth as it would produce a moment of "acceleration" forces that act by the "driving force of tir" to the Earth subsystem, by tilting the Earth's axis in a certain direction. If at some point, after a certain time, the "flywheel of tir" in circular motion on the surface of the "sphere" Earth was stopped, it transfer its angular momentum to the Earth in rotation since it would produce a momentum of forces opposed to the previous ( "deceleration"), bringing the axis in the original direction.
Remember the previous example of the student on the stool and bicycle wheel or flywheel? Well, in parallel with the case of the student on the stool, it were the same as if the student put the rotation of flywhhel and stop it, sloping in one direction when the flywheel accelerate and in the opposite direction when it stop, remaining to rotate in the original direction because the momentum acting on him is zero, being the sum of two opposites ones.
Question: What happens if the truck, during their acceleration, lose mass (i.e. losing the material with which they were loaded…) and are holding back when they are empty? Well, the moments of acceleration and deceleration would be different, their sum would not be zero and therefore the total force transmitted by the "flywheel of tir" to the Earth will cause the tilt of axis in a certain direction!
In the student case, it is as if he had speeded up a flywheel and had braked a mass different one.
Let us return now to tir: Even if vehicles could be united with each other to form a single homogeneous mass rotating there would be the problem of arrest them all simultaneously, but it is a problem not insurmountable. In any case, the time it takes to stop the truck in the rotation could be much less than that used to accelerate them, allocateing the tirs with an adequate equipment of brakes.
The effect produced by their rotary motion would depend on which side of the surface of Earth would be interested by the location of "flywheel to tir" (made up of tens of thousands of vehicles). From a purely theoretical reason, according to the second cardinal equation of mechanics, that time can cause both the tilt of the Earth's direction axis (the known 23.27 °) and the variation of rotating speed, because in general has a component orthogonal to the axis and a component parallel or antiparallel to the direction of rotation (depending on which side of the planet will operate the truck in a circle).
Example: imagine for simplicity that the axis of rotation of the earth is vertical; Well if the "driving force of tir" was placed on the equator, it would produce only a momentum orthogonal to the axis of rotation and thus only the variation of the rotation angle of the earth’s axis.
If the truck in a circle were made to act in a generic area in the north or south, that we would have a momentum acting on Earth directed in a direction where the generic components (parallel and orthogonal to the axis) would give life to the inclination of the axis of rotation and a variation in the speed of rotation. In the actual case being the axis of rotation inclined to 23.27 °, also a moment applied perpendicularly the equator would not be perpendicular to the direction of axis, but would also have a component parallel to it. Then the condition of squareness of the momentum produced by the flywheel of tir on Earth would be roughly in the Earth's surface between the equator and the Tropic of Cancer and / or Capricorn.
Obviously the diameter of the flywheel of tir, which has to produce the momentum needed to obtain the desired inclination of axis, is easy to calculate. Just know the moment of inertia, mass and angular velocity of the Earth, some astronomical parameters and all that.
In summary, everything (in the laboratory reference system) is based on the conservation of angular momentum L of a system when the total external forces and total M is zero: if the flywheel is blocked, the system stool + student buys an angular momentum ( which is the axis tilt system stool + student) that L of the whole system stool+ student + fly remains constant.
With regard to tir, (on the surface of the Earth) probably should be kept under control the effect that the truck produce when moving, along the meridians, and this why we are particularly interested in seeing the torque of internal forces to study their effect on Earth subsystem.
Because the effect is perceptible angular momentum of two subsystems Earth and tir must be comparable, for example, the ratio of the masses must not be too small, even if in principle an effect it might be still despite one of two subsystems is much more "light" of the other.
In "mass variable tirs" the mass deportation was part of the overall system and helped to determine the initial angular momentum. While in the first version you put in motion the "flywheel tir" and their next stop does not cause any change in overall (the system regains the angular momentum possessed before the truck begin to move), now the total angular momentum of the Earth + tir + expelled mass mass remains constant, while that of subsystem Earth + tir varies. The latter is the subsystem that interests us and therefore should be studied the forces exerted on it from the rest of the system (mass deportation).
To model all this would be quite long and complex, and other parameters should be set.
Put simply: the Earth rotates on itself, I call axis Z0 the axis NS which is also the axis of rotation.
I have a row of truck that move along a meridian (if they move along a parallel, the only effects might affect the magnitude of speed but not its direction).
To take account of the rotating system we must resort to Euler equations that describe the change in angular momentum in the reference system solidarity of the Earth. If we call x-axis orthogonal to z contained in the plan of the meridian, the moments of inertia of (Earth + tir) compared with axes x and z, Ix and Iz, coincide and are slightly smaller than Iy.
(The forces that carry between Earth and tirs have obvious component tangential to the meridian, but as the Earth rotates on itself the truck,to keep their route along the meridian, must also exercise a force parallel to the tangent, to counter the Coriolis force.)
The expulsion of the masses (at a rate dm / dt) can be described by taking an equal "push" av (speed of expulsion) for dm / dt, and directed tangentially to the meridian.
If all pushed agree (each tir throws away its cargo in the same side), twisting momentums due to all the push cause a total momentum direct along the y-axis (Ny) that vary the angular momentum of the subsystem Earth + tir along the same axis.
The Euler equations become in this case:














which mean precisely (inter alia) that the y component of angular velocity, initially nothing, grows over time (and consequently the same thing occur for the y component of angular momentum) ... with an incredible result .... tilt of the Earth's axis.
But abruptly changing the axis of rotation what happens to our homes, mountains, lakes, oceans etc? If you do it gradually, on next steps, "nothing" happen, see the earthquake in Sumatra (not tzumami). In reality, what may occur, since the composition of Earth uneven is the "slippage" of hard crust on the underlying pasty mass, It would thus a shifting of seismic faults that could act as happens when you experience the great earthquakes on the movement of the earth.
A simulation is prior, as is often quite necessary.
If we were to resort to geoingegneria mean that humanity has come to its end.
But perhaps my daughter Laura ( among the five winners of the Student Contest competition in the International Year of Planet Earth promoted by the United Nations) is right, the humanity can find the solution only rediscovering its roots…

We do not have to be violent with the nature. We have to love it!

by Laura Langone

....”From dust we were created, and to dust we shall return”... how many times we have heard these words pronounced by the "unmentionables", in front of the apologists of the religious metaphysics? Or better, "earth we were and earth we shall return". It there has always been in the human conception an indissoluble tie between nature and life: on the one hand the seed that sprouts, the plant that grows and matures and then dies returning to the earth; on the other the child who is born, crosses adolescence and adult age in order then to die returning to the earth. Since the dawn men have inquired on their genesis, on their relationship with the created, with the earth.

In the fifth century B.C. Empedocles had assumed four original and immutable roots (rhizomata) as principles or archai from which the whole thing, the being, derived: fire, water, air and earth, joint and separated by two cosmic forces: Love or Friendship (Aphrodite or Philìa) and Hatred and Discord (Neikos). However, one of the first unmentionable to be put on the dock for having denied Gods existed is Anassagora from Clazomene, author of a sort of "Big Bang". He, in fact, embraces the thesis of unity and homogeneity of the being formulated by the previous philosophers. However, he denies that it is immovable and lacking of determining factors; imagining it as an original chaotic mixture (migma) in which all the qualitative and infinitely divisible principles or "seeds", of which the various bodies will be constituted, reside; therefore earth in the life, life in the earth, man and nature.

Then the organisation of the migma becomes the effect of the nous or intelligence, lighter and thinner matter that guides and partitions the seeds in different proportions in the various things, that is "all is in all". On other hand, Democritus admits an infinite entity, a plurality of countless entities (atoms), which differ among them for shape and size, order and position. Nevertheless, the one who fully deserves the title of "unmentionable" is certainly Epicurus who, following Democritus, even if with some divergence, resumes the atomic theory: the atoms are infinite, unalterable and imperceptible; however, their shapes are not several as in the previous theory but finite; their eternal movement is not dispersion but, having weight, they are subject to fall vertically and to a minimal declination (parènkclesis), a sort of gravity.

Nowadays we are in the age of secularisation and of religions at the same time, we have lost the "innocence" of our ancestors, we have stopped to put ourselves in relationship with the nature, with our mother: the earth. We have betrayed, oppressed her. History is nothing else that the history of the nature, of the `homo naturalis’ who has abandoned the ‘amore naturaliter’, who it is trying to kill his mother and his father; differently from Oedipus, nevertheless, he is aware of that.

That happened when the man abandoned his natural intellect, in order to chase a unnatural intellect, or unknowledgeable, to say it as Kant; that is when it abandoned the reason for the

spiritual fond contemplation. And, in fact, God said: "Let us make man in our image, after our likeness. And let him have dominion over the fish of the sea and over the birds of the heavens and over the livestock and over all the earth and over every reptiles that creeps on the earth (Genesis 1,26-27). What He, Lord of the Skies, had previewed exactly happened. The man indeed dominates, however such dominion is precarious, suicide, since the man’s destiny is indissolubly linked to the nature: when the nature perishes, same fate will happen to the man and then neither there will be earth, nor life. "We do not have to be violent with the nature. We have to love it instead"…. (Epicurus).