Se in Italian literature there are several authors who talk about “Saracen olive tree”, this category of olive trees is not mentioned in the publications agronomiche, beyond a normal reference to centuries-old, twisted trees dating back to the Arab domination in Sicily, at the time of the Saracens (827-1091). There are many theories, even the most bizarre, to explain the twisted shape of the trunk of these centuries-old olive trees, but only scientists have established the causes.
These centenary olive trees, which are in ours Boreal Emisphere, have a noticeable clockwise rotation of the trunk (right-handed) and this is very evident in the south of Italy, while to the south of the planet, i.e. below the equator, or rather in the southern hemisphere, as we can observe in the Azape and Huasco valleys of Chile, the rotation of the trunk is counterclockwise (levorotatory).
We can see this rotation because these olive trees, of the variety sevillana, they were brought in the 1560th century, directly from Spain, and planted in Peru in XNUMX, by the Prosecutor of this country.
Biology teaches us that the shape of any organism depends on its own genetic heritage that from the influences oftechnology in which it developed. In the case of Saracen olive trees, their twisted, twisted shape depends only on the forces of the environment and not on DNA.
Experts have determined that the cause is the Gaspard-Gustave de Coriolis force, a force related like centrifugal force, which it acts on those bodies that move in a north-south direction on the surface of the Earth. The Coriolis force develops for the rotation of the earth's axis (the Earth travels 360° with an angular velocity of 15° per hour), ma the tangential speed, that is, the linear speed of every point on the Earth, is different from point to point: maximum at the equator while it is zero at the two Poles.
The linear speed is not the same for every point on the Earth, it changes as the latitude varies. For those on the equator it will be around 1,668 km/h, on others for example located at 40°N, it will be 1,278 km/h. Having said that, what happens if a body from the equator moves towards the north pole? It encounters points on the earth's surface that have different, increasingly smaller linear speeds. Due to inertia, the body tends to maintain its initial velocity along its trajectory, therefore it is ahead of the points on the surface it encounters and undergoes a deviation. This is the Coriolis effect.
The Coriolis force and the centrifugal force are not directed in the same direction, rather they are perpendicular as the Coriolis force is perpendicular to the relative speed of the body while the centrifugal force has a radial direction, like the relative speed.
In practice, a point located at the equator will have to travel approximately 40 thousand km in 24 hours, while a point close to the Pole will travel almost zero distance, at most it will rotate on itself.
This force also affects the trajectories of aircraft.
There is the principle of inertia, or Newton's first law, which says that a body tends to maintain its speed if not subjected to external forces. So an object moving from the equator to the Pole will tend to maintain its linear speed, while the Earth will rotate more and more slowly beneath it, therefore "taking advantage" compared to it. On the contrary, moving from the Pole to the equator, he will see the Earth moving faster and faster beneath him, and will be as if slowed down compared to it, i.e. "late".
Combining this with the Earth's rotation, we have that in the Northern Hemisphere (ours), in anti-clockwise rotation, the bodies will tend to have a deviation to the right (relative to its own motion) e in the Southern Hemisphere (in clockwise rotation) to the left.
In other words, in the northern hemisphere a body moving from the equator to the pole moves eastward, from the pole to the equator westward. The opposite in the southern hemisphere.
Even the masses of water and air moving from the equator towards the poles are deflected by the Coriolis force, which acts in rotating bodies. Some winds such as monsoons, and some ocean currents, go to the right when they "rise" in the Northern Hemisphere and to the left when they "fall" in the Southern Hemisphere
We also know that the Earth's axis is inclined with respect to the perpendicular to the ecliptic plane on average by 23°27' with oscillations ranging from 21,5° to 24,5° and that therefore the inclination varies in the medium-long term period.
These changes happen very slowly and imperceptibly, and it is for this reason that we can only notice it in centenary olive trees. After a certain age the olive tree grows more and more slowly until it is influenced by the slow movement of the earth's rotation. And one of the frequent characteristics of the olive trees of Puglia is that of presenting a twist from bottom to top always in the same direction, that is, clockwise.
We know that the movement of the Earth affects the direction of rotation of fluids, both gaseous and liquid, and imparts an impulse in the counterclockwise direction in the northern hemisphere, the Coriolis Force. For example, if you observe the images of Atlantic disturbances, in particular low pressure cyclones, transmitted by geostationary satellites, you see that they are vortices that spin in the opposite direction to that of the hands of a clock. But if we observe the phenomenon in the southern hemisphere, the direction is reversed. And this happens as soon as you cross the line of the Earth's equator.
This is a phenomenon that physicists know how to explain to us, and which acts on all fluids.
Well after this premise, by chance, I found that, an olive tree centennial and cultivar Vocio, positioned in front of the Filippi oil mill, in the Fabbri hamlet of Giano dell'Umbria (PG), had a right-handed rotation of the trunk (42°50'37” and N 12°37'2” E).
It is a very rare phenomenon, not so much due to seniority, as in Umbria we have several monumental olive trees such as the olive tree of Sant'Emiliano in Trevi, the olive tree of Macciano a Giano, the Rajo in Amelia, that of Villastrada di Castiglione del Lago), as well as its resistance to this latitude and altitude (330 meters above sea level) because they have been frosts are frequent and therefore this olive tree survived those of 1929, 1957, 1985 and many others before, of which we have no memory.
Embedded in the earth, these living sculptures grow, rotating together with the planet that hosts them, and at the same time bearing witness at 360 degrees to everything that surrounds them and that they have seen with their foliage over the centuries.
References
https://www.vigata.org/bibliografia/AbbracciareUliviSaraceni.pdf
Teatro della Pergola, 'The Giants of the Mountain' inaugurate the season
https://attivissimo.blogspot.com/2016/12/perche-le-antenne-radio-delle-auto.html?m=1&fbclid=IwAR297JcVWtNCG0jAkWawNdNTMJG6sImhuryW0qR5MA0xlJXehXDRbBRUB2s
https://www.slideserve.com/irisa/evoluzione-della-terra?utm_source=slideserve&utm_medium=website&utm_campaign=auto+related+load
https://it.quora.com/Perch%C3%A9-la-forza-di-coriolis-%C3%A8-massima-ai-poli-e-assente-allequatore
