Antipyretics for children are prescribed by a pediatrician. But there are emergency situations with fever when the child needs to be given medicine immediately. Then the parents take responsibility and use antipyretic drugs. What is allowed to be given to infants? How can you lower the temperature in older children? What medications are the safest?
The earth rotates around an inclined axis from west to east. Half of the globe is illuminated by the sun, it is day there at that time, the other half is in the shadow, there it is night. Due to the rotation of the Earth, the cycle of day and night occurs. The Earth makes one revolution around its axis in 24 hours - a day.
Due to rotation, moving currents (rivers, winds) are deflected in the northern hemisphere to the right, and in the southern hemisphere to the left.
Rotation of the Earth around the Sun
The Earth rotates around the sun in a circular orbit, completing a full revolution in 1 year. The earth's axis is not vertical, it is inclined at an angle of 66.5° to the orbit, this angle remains constant during the entire rotation. The main consequence of this rotation is the change of seasons.
Consider the rotation of the Earth around the Sun.
- December 22- winter solstice. The southern tropic is closest to the sun (the sun is at its zenith) at this moment - therefore, it is summer in the southern hemisphere, and winter in the northern hemisphere. Nights in the southern hemisphere are short; on December 22, in the southern polar circle, the day lasts 24 hours, night does not come. In the northern hemisphere, everything is the other way around; in the Arctic Circle, the night lasts 24 hours.
- 22nd of June- day of the summer solstice. The northern tropic is closest to the sun; it is summer in the northern hemisphere and winter in the southern hemisphere. In the southern polar circle, night lasts 24 hours, but in the northern circle there is no night at all.
- March 21, September 23- days of the spring and autumn equinoxes The equator is closest to the sun; day is equal to night in both hemispheres.
Hello dear readers! Today I would like to touch on the topic of the Earth and, and I thought that a post about how the Earth rotates would be useful to you 🙂 After all, day and night, and also the seasons, depend on this. Let's take a closer look at everything.
Our planet rotates around its axis and around the Sun. When it makes one revolution around its axis, one day passes, and when it revolves around the Sun, one year passes. Read more about this below:
Earth's axis.
Earth's axis (Earth's rotation axis) – this is the straight line around which the Earth’s daily rotation occurs; this line passes through the center and intersects the surface of the Earth.
The tilt of the Earth's rotation axis.
The Earth's rotation axis is inclined to the plane at an angle of 66°33´; thanks to this it happens. When the Sun is above the Tropic of the North (23°27´ N), summer begins in the Northern Hemisphere, and the Earth is at its farthest distance from the Sun.
When the Sun rises above the Tropic of South (23°27´ S), summer begins in the Southern Hemisphere.
In the Northern Hemisphere, winter begins at this time. The attraction of the Moon, Sun and other planets does not change the angle of inclination of the earth's axis, but causes it to move along a circular cone. This movement is called precession.
The North Pole now points toward the North Star. Over the next 12,000 years, as a result of precession, the Earth's axis will travel approximately halfway and will be directed towards the star Vega.
About 25,800 years constitute a complete precessional cycle and significantly influence the climate cycle.
Twice a year, when the Sun is directly above the equator, and twice a month, when the Moon is in a similar position, the attraction due to precession decreases to zero and there is a periodic increase and decrease in the rate of precession.
Such oscillatory movements of the earth's axis are known as nutation, which peaks every 18.6 years. In terms of the significance of its influence on climate, this periodicity ranks second after changes in seasons.
The rotation of the Earth around its axis.
Daily rotation of the Earth - the movement of the Earth counterclockwise, or from west to east, as viewed from the North Pole. The rotation of the Earth determines the length of the day and causes the change between day and night.
The Earth makes one revolution around its axis in 23 hours 56 minutes and 4.09 seconds. During the period of one revolution around the Sun, the Earth approximately makes 365 ¼ revolutions, this is one year or equal to 365 ¼ days.
Every four years, another day is added to the calendar, because for each such revolution, in addition to a whole day, another quarter of a day is spent. The Earth's rotation gradually slows down the Moon's gravitational pull, lengthening the day by about 1/1000th of a second every century.
Judging by geological data, the rate of rotation of the Earth could change, but not by more than 5%.
Around the Sun, the Earth rotates in an elliptical orbit, close to circular, at a speed of about 107,000 km/h in the direction from west to east. The average distance to the Sun is 149,598 thousand km, and the difference between the smallest and largest distance is 4.8 million km.
The eccentricity (deviation from the circle) of the Earth's orbit changes slightly over the course of a cycle lasting 94 thousand years. It is believed that the formation of a complex climate cycle is facilitated by changes in the distance to the Sun, and the advance and departure of glaciers during ice ages are associated with its individual stages.
Everything in our vast Universe is arranged very complexly and precisely. And our Earth is just a point in it, but this is our home, which we learned a little more about from the post about how the Earth rotates. See you in new posts about the study of the Earth and the Universe🙂
Regardless of the fact that the constant movements of our planet are usually imperceptible, various scientific facts have long proven that planet Earth moves along its own strictly defined trajectory not only around the Sun itself, but also around its own axis. This is what determines the mass of natural phenomena observed by people every day, such as the change in time of day and night. Even at this moment, reading these lines, you are in constant motion, a movement that is caused by the movement of your native planet.
Fickle movement
It is interesting that the speed of the Earth itself is not a constant value, for reasons that scientists, unfortunately, have not yet been able to explain, however, it is known for certain that each century the Earth slightly slows down the speed of its normal rotation by an amount equal to approximately 0. 0024 seconds. It is believed that such an anomaly is directly related to a certain lunar attraction, which determines the ebb and flow of the tides, on which our planet also spends a significant share of its own energy, which “slows down” its individual rotation. The so-called tidal protrusions, moving as usual in the direction opposite to the Earth's course, cause the emergence of certain frictional forces, which, in accordance with the laws of physics, are the main braking factor in such a powerful space system as the Earth.
Of course, there is actually no axis; it is an imaginary straight line that helps make calculations.
In one hour, it is believed that the Earth rotates 15 degrees. It’s not hard to guess how long it takes for it to completely turn around its axis: 360 degrees - in one day in 24 hours.
Day at 23 o'clock
It is clear that the Earth rotates around its own axis in the 24 hours familiar to people - an ordinary earthly day, or more precisely - in 23 hours minutes and almost 4 seconds. The movement invariably occurs from the western part to the eastern part and nothing else. It is not difficult to calculate that under such conditions the speed at the equator will reach about 1670 kilometers per hour, gradually decreasing as it approaches the poles, where it smoothly goes to zero.
It is impossible to detect with the naked eye the rotation performed by the Earth at such a gigantic speed, because all surrounding objects move along with people. All planets in the solar system undergo similar movements. For example, Venus has a much lower speed of movement, which is why its days differ from those on Earth by more than two hundred and forty-three times.
The fastest planets known today are considered to be Jupiter and the planet Saturn, completing their full rotation around their axis in ten and ten and a half hours, respectively.
It should be noted that the rotation of the Earth around its axis is an extremely interesting and unknown fact that requires further close study by scientists around the world.
The planet rotates around itself in the direction from west to east. We do not feel this process because all objects move simultaneously and parallel to each other along with the cosmic body. The rotation of the planet has the following features and consequences:- Day follows night.
- The Earth makes a full revolution in 23 hours and 57 minutes.
- When viewed from the North Pole, the planet rotates counterclockwise.
- The rotation angle is 15 degrees per hour and is the same anywhere on Earth.
- The linear speed of revolutions throughout the planet is heterogeneous. At the poles it is zero and increases as it approaches the equator. At the equator, the rotation speed is approximately 1668 km/h.
Important! The speed of movement decreases by 3 milliseconds every year. Experts attribute this fact to the gravity of the Moon. Influencing the ebb and flow of the tides, the satellite seems to pull water toward itself in the direction opposite to the movement of the Earth. A friction effect is created on the bottom of the oceans, and the planet slows down slightly.
Rotation of the planet around the Sun
Our planet is the fifth largest and third farthest from the Sun. It formed from elements of the solar nebula about 4.55 billion years ago. In the process of formation, the Earth acquired the shape of an irregular ball and established its unique orbit, more than 930 million km long, in which it moves around a large star at an approximate speed of 106,000 km/h. It completes a full revolution around the Sun in a year, or, to be more precise, in 365.2565 days. Researchers note that the orbit of the moving planet is not perfectly round, but has the shape of an ellipse. When the average distance to a star is 151 million km, then when orbiting around it, the distance increases to 5.8 million km.Important! Astronomers call the point of the orbit furthest from the Sun Aphelion, and the planet passes it at the end of June. The closest one is Perihelion, and we pass it together with the planet at the end of December.The irregular shape of the orbit also affects the speed at which the Earth moves. In summer it reaches its minimum and is 29.28 km/s, and after passing the Aphelion point, the planet begins to accelerate. Having reached a maximum speed of 30.28 km/s at the perihelion boundary, the cosmic body slows down. The Earth goes through such a cycle endlessly, and life on the planet depends on the accuracy of its trajectory.
Important! When studying the Earth’s orbit more closely, astronomers take into account additional no less important factors: the attraction of all celestial bodies of the solar system, the influence of other stars and the nature of the rotation of the Moon.
Alternation of seasons
While making a revolution around the Sun, the Earth moves in the direction from west to east. During its travel, this celestial body does not change its angle of inclination, so in a certain part of its orbit it is completely facing one side. This period on the planet is perceived by the living world as summer, and on the side not facing the Sun at this time of year winter will reign. Thanks to the constant movement on the planet, seasons change.Important! Twice a year, a relatively identical seasonal state is established on both Hemispheres of the planet. At this time, the Earth is turned towards the Sun in such a way that it evenly illuminates its surface. This occurs in autumn and spring on the equinoxes.
Leap year
It is known that the planet makes a complete revolution around its axis not in 24 hours, as is commonly believed, but in 23 hours and 57 minutes. At the same time, it completes a circle in orbit in 365 days and 6.5 hours. Over time, the missing hours are added up and thus another day appears. They accumulate every four years and are marked on the calendar on February 29th. A year that has an additional 366th day is called a leap year.Important! The rotation of the Earth is influenced by its satellite - the Moon. Under its gravitational field, the planet's rotation gradually slows down, which increases the length of the day by 0.001 s with each century.
Distance between our planet and the Sun
As the Earth moves around the Sun, a centrifugal force arises between them. It has a contradictory character and pushes the planet away from the star. However, the planet rotates without changing its speed, which is perpendicular to the speed of its fall, which deviates its orbit from the direction of the Sun. This feature of the movement of cosmic bodies prevents them from falling onto the Sun and moving away from the Solar System. Thus, the Earth moves along a clear trajectory of its orbit. Back in the 16th century, the great Nicolaus Copernicus determined that the Earth is not the center of the Universe, but only revolves around the Sun. Now researchers have made significant progress in knowledge and calculations, but they are not able to influence the rotation trajectory and the nature of the star itself. Our planet has always been part of the solar system, and life on the planet depends on how far we are from its center and how we move relative to the star. To better understand the topic, also watch the educational video.The Earth, like any other celestial object, is in constant motion. Even if we humans don't feel it, the planet rotates on its axis and around the Sun at great speed. We don’t feel this because it’s like an airplane or a car - we move at the same speed as the vehicle, which is why the illusion of static is born.
What causes the Earth to rotate around its axis?
The Earth's graceful 24-hour rotation on its axis is one of the reasons why our home planet is habitable. In many ways, this is what allowed life to develop, thanks to the creation of a favorable temperature, which is achieved by a constant change of day and night.
Do not forget that not only the Earth has this feature - each planet in the solar system has its own unique rotation. For example, on tiny Mercury, which is closest to the Sun, one rotation occurs in 59 Earth days, and on Venus - a total of 243, and in addition, its movement occurs in the opposite direction.
Everyone knows that the Earth rotates, and this seems like banal information, but if you think about it, it is not entirely clear why this happens. To answer this question, we need to know how the entire solar system was formed.
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Why is the Earth's axis tilted?
Initially, the Solar System was just a huge cloud of dust and gas, which over time began to collapse, turning into a giant disk. He, in turn, constantly increased his speed of rotation, like a figure skater throwing his arms up to move faster. The sun formed in the center, and the planets began to gather further away from it. All objects that make up our system are on the same plane and move in the same direction because they all originated from the same disk of cosmic dust.
While the process of gluing together planets and other celestial bodies was taking place, there was no peace in the solar system, since the fragments constantly collided with each other, which led to their rotation. Sometimes the gravity of large fragments attracted small ones - this is how satellites appeared.
Why does the Earth rotate around its axis faster than other planets?
Scientists suggest that a huge object, approximately the size of Mars, crashed into our planet and thereby separated a huge piece from it, which later became the Moon. This collision caused the Earth to spin faster than other planets. But the gravity of the Moon affects the rotation of the Earth - it slows it down!
Interesting fact: The Earth is constantly slowing down its rotation. Scientists suggest that at the time the planet was formed, the day was only 6 hours long.. And now there are extremely accurate technologies that make it possible to calculate further deceleration - in a hundred years the day will be shorter by 2 milliseconds.
At what speed does the Earth rotate around its axis?
Speed is a relative concept because it always requires a certain reference point to calculate it. To calculate the speed of rotation around its axis, the rotation relative to the center of the planet is taken.
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Earth collisions with meteorites
The Earth makes one revolution in 23 hours 56 minutes and 4.09053 seconds, which is called the sidereal period. The circumference of the planet is 40,075 kilometers. In order to calculate the speed, you will need to divide the circle by time, then you get approximately 1674 km/h or 465 m/s.
The earth rotates around its axis at a speed of 1674 km per hour or 465 m/s.
But do not forget that the circumference of the planet changes depending on latitude, as the Earth narrows closer to the poles. Therefore, the planet spins at different speeds at different latitudes! The smaller the radius, the lower the speed. So at the North Pole and South Pole the rotation speed is practically zero.
If you are interested in finding out the rotation speed that can be achieved at a different latitude, then all you need to do is multiply the cosine of this latitude (it can be calculated on a calculator or simply looked at in the cosine table) by the rotation speed of the planet at the equator (1674 km/h). So the cosine of 45 degrees is equal to 0.7071 and it turns out that the speed at this latitude is: 1674x0.7071=1183.7 km/h.
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How long does it take to get to Mars?
Earth rotation speed for different latitudes
- 10°: 0.9848×1674=1648.6 km/h;
- 20°: 0.9397×1674=1573.1 km/h;
- 30°: 0.866×1674=1449.7 km/h;
- 40°: 0.766×1674=1282.3 km/h;
- 50°: 0.6428×1674=1076.0 km/h;
- 60°: 0.5×1674=837.0 km/h;
- 70°: 0.342×1674=572.5 km/h;
- 80°: 0.1736×1674=290.6 km/h
Interesting fact: Space agencies prefer to use the rotation of the Earth around its axis to their advantage. Since the rotation speed is highest near the equator, fewer resources are required to lift a spacecraft from zero latitude.
Cyclic braking
Scientists began to notice a correlation between seismic activity per year and the speed of the Earth’s rotation around its axis. It is believed that there is no direct relationship between these two phenomena, but it is important for specialists to find any clues that, firstly, will give a greater understanding of our planet, and secondly, can save thousands of lives.
Since everything is cyclical, the rotation of our home planet is cyclical. The Earth has five-year periods of cyclic deceleration and acceleration.
Earth's axis wobble
In physics, there are two concepts that are used to describe the oscillations of the Earth's axis - precession and nutation.
Precession is a phenomenon in which the angular momentum of a celestial body changes its direction in space. This movement can be seen in the example of a top, which when launched has a vertical axis of rotation, but the top has the property of gradual deceleration, during which the speed begins to be lost. Because of this, the axis begins to gradually deviate from the usual vertical. Due to this, the top begins to describe a shape similar to a cone. Such movement is precession.
