period of the Earth around its axis - a constant.Astronomically it is 23 hours 56 minutes and 4 seconds.However, researchers did not take into account a tiny error, rounding these numbers to 24 hours, or one earth day.One such revolution called diurnal rotation takes place from west to east.For a man from the Earth it looks like morning, afternoon and evening, replacing each other.In other words, sunrise, noon and sunset light is completely the same as the daily rotation of the planet.
What is Earth's axis?
Earth's axis can be visualized in the form of an imaginary line around which the third planet from the Sun and rotates.This axis intersects the surface of the Earth in two permanent locations - in North and South geographic poles.If, for example, mentally continue the direction of the Earth's axis up, then it will pass near the North Star.By the way, this explains the immobility of the Polar Star.It creates the effect that the celestial sphere moves around the axis, and hence around this star.
Another man from the Earth it seems like a starry sky rotates in the direction from east to west.But it is not.The apparent motion is a true reflection of the diurnal rotation.It is important to know that our planet is simultaneously involved in not one but at least two processes.It revolves around the Earth's axis and makes the orbital motion around a celestial body.
apparent movement of the sun - it is also a reflection of the true motion of the planet in its orbit around it.As a result, the day of the first, and then - the night.Note that one movement is unthinkable without the other!These are the laws of the universe.Moreover, if the period of revolution of the Earth around its axis is equal to one Earth days, while its motion around the celestial body - vacillates.To find out what affects these indices.
What affects the speed of orbital rotation of the Earth?
period of the Earth around its axis - a constant, can not be said about the speed with which the blue planet orbits the star.For a long time astronomers thought that the speed is constant.It turned out that there is no!Today, thanks to the most accurate measuring instruments, scientists have found a slight deviation in the previously received numbers.
reason for such variability - the friction generated during the tides.That it has a direct impact on reducing the orbital velocity of the third planet from the sun.In turn, the tides - a consequence of its actions on the Earth constant companion - the Moon.This turn of a planet around a heavenly body man does not notice, as well as the period of revolution of the Earth around its axis.But we can not ignore its attention to the seasons: spring gives way to summer, summer - autumn, and autumn - winter.And so it happens all the time.This is a consequence of the orbital motion of the planet, which lasts 365.25 days, or one Earth year.
is worth noting that the Earth moves relative to the sun unevenly.For example, at some points it is closest to the celestial bodies, and the other - the most distant from him.And again orbit around the Earth - it is not a circle but an oval or ellipse.
Why do people not to notice the daily rotation?
man will never be able to observe the planet's rotation, while on the surface.This is due to the difference in the size of our own and the world - he is too huge for us!The period of revolution of the Earth around its axis does not get noticed, but will be able to feel: day replaced night, and vice versa.This has already been discussed above.But what would happen if the blue planet was not able to rotate around its axis?Here's what: on one side of the earth would have been eternal day, and on the other - the eternal night!Awful, is not it?
Good to know!
Thus, the period of revolution of the Earth around its axis is almost 24 hours, and the time of her "journey" around the sun - about 365.25 days (one Earth year) as this value - changeable.We draw your attention to the fact that, in addition to considering the motion of the two, the Earth is involved in the other.For example, she and the rest of the planets makes a motion with respect to the Milky Way - our home galaxy.In turn, the Milky Way makes a motion with respect to other neighboring galaxies.And it is because the universe has not been and never will be nothing immutable and motionless!It is to be remembered for a lifetime.
