Many familiar to us from childhood, especially the processes of life are the result of a cosmic scale.Day and night, the seasons, the duration of the period during which the Sun is above the horizon, due to the fact, as well as the speed with which the Earth rotates, the peculiarities of its movement in space.
imaginary line
axis of any planet - speculative design, created for the convenience of describing the motion.If we mentally draw a line through the poles, it will be the axis of the Earth.Rotation around it - one of the two main movements of the planet.
axis is not with the plane of the ecliptic (the plane of the Earth's rotation around the sun) 90º, but deviates from the perpendicular to 23º27 '.It is believed that the planet rotates from west to east, that is counterclockwise.It looks so its movement around the axis, if you watch him at the North Pole.
irrefutable evidence
once believed that our planet is stationary and the stars fixed in the sky revolve around her.Quite a long time in history no one was interested in the speed with which the Earth revolves in orbit or axis, since the very concepts of "axis" and "orbit" does not fit into the scientific knowledge of the period.Experimental evidence for the fact of the constant movement of the Earth's axis was obtained in 1851 by Jean Foucault.It finally convinced all those who in the nineteenth century still doubted it.
Experience was held at the Paris Pantheon, which were placed under the dome of the pendulum and the circle with divisions.Swinging pendulum with each new movement shifted into several divisions.This is possible only when the rotation of the planet.
Speed
How quickly the Earth rotates around its axis?The unequivocal answer to this question is quite difficult to give, because the speed of different geographic locations varies.The closer to the equator of the area, so it is above.In the area of Italy speed, for example, estimated at 1,200 km / h.On average, the planet for an hour overcomes 15º.
With the speed of rotation of the Earth is connected length of the day.The length of time for which the planet makes one revolution around the axis determined by two methods.To determine the so-called sidereal day as a reference system selected any star except the sun.It lasts 23 hours, 56 minutes and 4 seconds.If the starting point is taken our star, the solar day is called.Their value an average of 24 hours.It varies somewhat depending on the position of the planets relative to the light that affects the speed of rotation around the axis and the speed with which the Earth revolves in its orbit.
Around the center
second major movement of the planet - is its "spin" on the orbit.Constant movement in a slightly elongated trajectory people felt most by the changing seasons.That is the speed with which the Earth moves around the Sun, it expressed to us primarily in units of time: one turn takes 365 days 5:00 48 minutes 46 seconds, ie the astronomical year.The exact figure clearly explains why every four years in February, an additional day.It represents the amount accumulated during that time hours are not included in the received 365 days of the year.
Features trajectory
As already noted, the speed with which the Earth revolves in its orbit, due to the characteristics of the latter.The trajectory of a planet is different from a perfect circle, it is slightly extended.As a result, the Earth is closer to the luminary, then moves away from it.When a planet and the Sun shared the minimum distance, this state is called perihelion.The maximum distance corresponds to aphelion.The first falls on January 3, the second - on the 5th of July.And for each of these points is the question: "What is the speed the Earth rotates in its orbit?" - Has its answer.For aphelion is 29.27 km / s for the perihelion - 30.27 km / s.
Day length
fact, the speed with which the Earth rotates in its orbit, and the whole movement of the planets around the sun have a number of consequences that determine the many nuances of our lives.For example, the movement affecting the duration of the day.The sun constantly changes its position in the sky: Moves the sunrise and sunset, it is a somewhat different altitude above the horizon at noon.As a result, changing the length of day and night.
coincide these two quantities only in the equinox, when the center of the Sun crosses the celestial equator.The slope of the axis at the same time is neutral with respect to the luminary, and its rays fall perpendicularly on the equator.The vernal equinox falls on March 20-21, in the autumn - on September 22-23.
Solstice
Once a year the day reaches its maximum duration, and after six months - a minimum.These dates are called solstice.Summer falls on June 21-22, and winter - on December 21-22.In the first case, because our planet is in relation to the luminary that the northern edge of the axis of looking in the direction of the sun.As a result, the rays fall perpendicularly to the northern tropics and cover the entire area of the Arctic Circle.In the Southern Hemisphere, while, conversely, the sun's rays reach only the area between the equator and the Arctic Circle.
During the winter solstice events occur in the same way, only the hemisphere change roles: covered South Pole.
Seasons
Orbital position not only affects the speed with which the Earth moves around the sun.By changing the distance separating from the sun and the tilt axis of the planet for a year unevenly distributed solar radiation.This, in turn, causes a change of seasons.Moreover, the duration of the winter and summer semester is different: the first is 179 days, and the second - 186. This mismatch results in all the same tilt axis relative to the plane of the ecliptic.
Belt-light
Circling the Earth in its orbit has another consequence.The annual movement leads to a change in the position of the sun above the horizon, with the result that the planet formed belt illumination:
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Hot situated on 40% of the Earth between the South and the North of the tropics.As the name implies, here comes the most heat.
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temperate zone - between the Arctic Circle and the tropics - are characterized by a pronounced change of seasons.
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Polar belt is located above the Arctic Circle, have a low temperature throughout the year.
movement of planets in general and, in particular, the speed with which the Earth revolves in its orbit, and influence on other processes.Among them, the rivers, the seasons, the rhythms of life of certain plants, animals and humans.In addition, the rotation of the earth because of its effect on the illumination and the surface temperature influences the agricultural work.
today is how the speed of rotation of the Earth, what is its distance from the Sun, and other features associated with the movement of the planets, studied in school.However, if you think about it, they are quite obvious.When such a thought comes to mind, I want to sincerely thank the scientists and researchers who are in many ways just because of its uncommon mind could open the cosmic laws of life of the Earth, to describe them and then prove and explain the rest of the world.
