Period of revolution of the Earth around its axis -the value is constant. Astronomically, it is 23 hours 56 minutes and 4 seconds. However, the scientists did not take into account the insignificant error, rounding up these figures to 24 hours, or some terrestrial days. One such turn is called the daily rotation and occurs from west to east. For a person from the Earth it looks like morning, afternoon and evening, succeeding each other. In other words, the sunrise, noon and sunset completely coincide with the daily rotation of the planet.
The Earth's axis can be thought of in the form ofan imaginary line around which the third planet from the Sun rotates. This axis crosses the Earth's surface at two constant points - in the North and South geographical poles. If, for example, mentally continue the direction of the earth's axis up, it will pass next to the North Star. By the way, this explains the immobility of the Polar Star. An effect is created that the celestial sphere moves around the axis, and hence, around this star.
Another person from Earth seems that the starry skyRotates in the direction from east to west. But this is not so. The apparent movement is only a reflection of the true daily rotation. It is important to know that our planet simultaneously participates not in one, but at least in two processes. It turns around the earth's axis and makes an orbital motion around the heavenly body.
The apparent movement of the Sun is the samereflection of the true motion of our planet in its orbit around it. As a result, first comes the day, and then - the night. Let us note that one movement is inconceivable without the other! These are the laws of the universe. In this case, if the period of revolution of the Earth around its axis is equal to one earth day, the time of its movement around the heavenly body is variable. We learn what affects these indicators.
The period of revolution of the Earth around its axis isthe value is constant, which can not be said about the speed with which the blue planet moves in orbit around the luminary. For a long time, astronomers thought that this speed is constant. It turned out that no! At present, thanks to the most accurate measuring devices, scientists have found a slight deviation in previously obtained figures.
The reason for this variability is the friction that arisesduring the sea tides. It directly affects the reduction of the orbital velocity of the third planet from the Sun. In turn, the ebbs and tides are the result of the action on the Earth of its constant moon moon. Such a revolution of the planet around the heavenly body does not notice a person, as well as the period of revolution of the Earth around the axis. But we can not but pay attention to the seasons: spring is replaced in summer, summer is in autumn, and autumn is in winter. And it happens all the time. This is the result of the orbital motion of the planet, lasting 365.25 days, or one earthly year.
It should be noted that the Earth is moving relativelyThe sun is uneven. For example, at some points it is the closest to the heavenly body, while in others it is most distant from it. And again: the orbit around the Earth is not a circle, but an oval, or an ellipse.
Man will never be able to notice the rotationplanet, being on its surface. This is due to the difference in the size of our and the globe - it is too huge for us! The period of revolution of the Earth around its axis can not be noticed, but it will be possible to sense: the day will change at night and vice versa. This has already been discussed above. But what if the blue planet could not rotate around the axis? And here's what: on one side of the Earth would be an eternal day, and on the other - an eternal night! Awful, is not it?
So, the period of revolution of the Earth around its axisis almost 24 hours, and the time of its "journey" around the Sun is about 365.25 days (one earth year), since this quantity is unstable. Let's pay your attention to the fact that, in addition to the two considered movements, the Earth participates in others. For example, she, along with the rest of the planets, is moving in relation to the Milky Way - our native Galaxy. In turn, the Milky Way makes some movement with respect to other neighboring galaxies. And everything happens because in the universe there was and never will be anything immutable and immovable! This must be remembered for life.