What is the earth's equator km. Countries through which the equator passes. Other important parameters of the blue planet
7 hectares is a square with a side of 700 m (hecto - a hundred).
A lot or a little - depends on the purpose of use. Planting potatoes is just that. You won't go hungry. Not enough for an airport.For comparison: the football field is not much smaller than a hectare.
soon we will fly with my mother to rest, and so I think that my mother will be in the cockpit .. to educate pilots and teach them to fly the plane correctly. at least when me or dad is driving, she, a person who has never driven a car, always teaches us how to do it right
10 km by 10 km? God, do you want to open a reserve?
Question. How
What does the day and night side of the Earth look like from a height? What does the sky look like, the sun,
Moon, stars? Answer. From a height, the day side of the Earth is visible very well, well
coasts of continents, islands, large rivers, large reservoirs are distinguishable,
terrain folds. When I flew over our land, I clearly saw
large squares of collective farm fields and one could understand where the arable land and where
meadow. Previously, I had to climb to a height of no more than 15 thousand meters. FROM
the satellite ship can be seen, of course, worse than from an airplane, but still very, very
OK. During the flight, I had the opportunity to see with my own eyes for the first time
spherical shape of the earth. This is what it looks like when you look at the horizon. Necessary
to say that the picture of the horizon is very peculiar and extraordinarily beautiful. Can
to see the unusually colorful transition from the light surface of the Earth to
a completely black sky with stars visible. This transition is very thin,
like a film-belt surrounding the globe. She is pale blue. And so
this whole transition from blue to black is unusually smooth and
Beautiful. It's even hard to put it into words. And when I came out of the earth's shadow, then
the horizon looked different. It had a bright orange stripe, which then
changed back to blue and back to deep black. I didn't see the moon. Sun
in space it shines several tens of times brighter than we have on Earth. The stars are visible
very good: they are bright, clear. The whole picture of the sky is much more contrast,
than we see it from our Earth.Will it do? Oo
Z.Y. did you get banned by google or what??? Oo
Z.Y.S. and according to the potential field -
up to weightlessness 80 and until the complete end of the atmosphere somewhere around 50,000. The ISS flies at 340 kilometers
Astronomers from the US and Canada have measured the boundary of the influence of atmospheric winds and the beginning of the impact of cosmic particles. She was at an altitude of 118 kilometers, although NASA themselves consider the boundary of space 122 km. At this altitude, the shuttles switch from conventional maneuvering using only rocket engines to aerodynamic maneuvering with "reliance" on the atmosphere.
Equator
What is it anyway?
Equator- a line of section of the earth's surface by a plane passing through the center of the Earth, perpendicular to the axis of its rotation. The length of the equator is 40075.696 km. Along the equator, day is always equal to night.
Equator divides the globe into northern and southern hemispheres.
Equator serves as the beginning of the calculation of geographic latitude (the latitude of the equator is 0 degrees).
lat. Aequator - equalizer
/ Yandex Encyclopedia /
EQUATOR m lat. equinox, - equinox; a circle suspended from the axis of the world and dividing the imaginary heavenly firmament and our earth into two equal halves: northern and southern; then the heavenly, and this is the earthly equinox, under which days and nights are always equal, and the latitude of the place is zero. sit on equator, be penniless. equatorial, equatorial, equinox.
/ Explanatory Dictionary of the Living Great Russian Language by Vladimir Dal /
Equator, an imaginary circle on the earth's surface, spaced at an equal distance from both poles and dividing the globe into two equal hemispheres. The circumference of the earth E. = 5400 geographic. miles = 4070 km., diameter = 12756 km. Heavenly equator .- great circle celestial sphere, whose plane is perpendicular to the line connecting the poles of the sphere, and parallel to the plane of the earth equator . For the inhabitants of the earth equator celestial equator passes through the zenith.
/Small encyclopedic Dictionary Brockhaus and Efron /
Equator
(Late Latin aequator, from Latin aequo - I make equal) geographical, terrestrial, great circle the globe, all points of which are 90 gr ; a line of section of the earth's surface by a plane perpendicular to the axis of rotation of the earth and passing through its center. Circumferenceequator 40,075.696 km. Equatordivides the globe into two hemispheres - Northern and Southern. Fromequatorgeographical latitudes from 0 to 90 are counted to the north and south gr . The sun is overequatorat the zenith twice a year: on the days of the spring (March 20-21) and autumn (September 23) equinoxes.
Now you know that in the fabulous Universe of our distant ancestors, the Earth did not even resemble a ball. The inhabitants of Ancient Babylon represented it as an island in the ocean. The Egyptians saw it as a valley stretched from north to south, in the center of which was Egypt. And the ancient Chinese at one time depicted the Earth as a rectangle ... You smile, imagining such an Earth, but how often have you thought about how people guessed that the Earth is not an infinite plane or a disk floating in the ocean? When I asked the guys about this, some said that people learned about the sphericity of the Earth after the first trips around the world, while others recalled that when a ship appears from behind the horizon, we first see the masts, and then the deck. Do such and some similar examples prove that the Earth is a sphere? Hardly. After all, you can go around and around ... a suitcase, and the upper parts of the ship would appear even if the Earth had the shape of a hemisphere or looked like, say, a ... log. Think about it and try to depict what is said in your drawings. Then you will understand: the examples given show only that The earth is isolated in space and possibly spherical.
How did you know that the Earth is a sphere? It helped, as I already told you, the Moon, or rather, lunar eclipses, during which the round shadow of the Earth is always visible on the Moon. Arrange a small "shadow theater": illuminate objects of various shapes in a dark room (a triangle, a plate, a potato, a ball, etc.) and notice what kind of shadow they get on the screen or just on the wall. Make sure only the ball always casts a circle shadow on the screen. So, the Moon helped people to know that the Earth is a sphere. To this conclusion, scientists Ancient Greece(for example, the great Aristotle) came as early as the 4th century BC. But for a very long time, the "common sense" of a person could not come to terms with the fact that people live on a ball. They could not even imagine how it is possible to live on the “other side” of the ball, because the “antipodes” located there would have to walk upside down all the time ... But wherever a person is on the globe, a stone thrown up everywhere will be under the influence of force gravity of the Earth to fall down, that is, to the earth's surface, and if it were possible, then to the center of the Earth. In fact, people, of course, nowhere, except for circuses and gyms, do not have to walk upside down and upside down. They walk normally anywhere on the Earth: the earth's surface is under their feet, and the sky is above their heads.
Around 250 BC, a Greek scholar Eratosthenes first accurately measured the globe. Eratosthenes lived in Egypt in the city of Alexandria. He guessed to compare the height of the Sun (or its angular distance from a point overhead, zenith, which is called - zenith distance) at the same time in two cities - Alexandria (in northern Egypt) and Syene (now Aswan, in southern Egypt). Eratosthenes knew that on the day of the summer solstice (June 22) the Sun was at noon illuminates the bottom of deep wells. Therefore, at this time the Sun is at its zenith. But in Alexandria at this moment the Sun is not at its zenith, but is separated from it by 7.2 °. Eratosthenes obtained this result by changing the zenith distance of the Sun with the help of his simple goniometric tool - the scaphis. This is just a vertical pole - a gnomon, fixed at the bottom of a bowl (hemisphere). The skafis is installed so that the gnomon assumes a strictly vertical position (directed to the zenith). The pole illuminated by the sun casts a shadow on the inner surface of the skafis divided into degrees. So at noon on June 22 in Siena, the gnomon does not cast a shadow (the Sun is at its zenith, its zenith distance is 0 °), and in Alexandria, the shadow from the gnomon, as can be seen on the scale of the skafis, marked a division of 7.2 °. At the time of Eratosthenes, the distance from Alexandria to Syene was considered equal to 5000 Greek stadia (about 800 km). Knowing all this, Eratosthenes compared an arc of 7.2 ° with the entire circle of 360 ° degrees, and a distance of 5000 stadia - with the entire circumference of the globe (we denote it by the letter X) in kilometers. Then from the proportion
it turned out that X = 250,000 stages, or about 40,000 km (imagine this is true!).
If you know that the circumference of a circle is 2πR, where R is the radius of the circle (and π ~ 3.14), knowing the circumference of the globe, it is easy to find its radius (R):
It is remarkable that Eratosthenes was able to measure the Earth very accurately (after all, even today it is believed that the average radius of the Earth 6371 km!).
But why is it mentioned here average radius of the earth, Aren't all spheres the same radius? The fact is that the figure of the Earth is different from the ball. Scientists began to guess about this back in the 18th century, but what the Earth really is - is it compressed at the poles or at the equator - it was difficult to find out. To understand this, the French Academy of Sciences had to equip two expeditions. In 1735, one of them went to carry out astronomical and geodetic work in Peru and did this in the equatorial region of the Earth for about 10 years, and the other, Lapland, worked in 1736-1737 near the Arctic Circle. As a result, it turned out that the length of the arc of one degree of the meridian is not the same at the poles of the Earth and at its equator. The meridian degree turned out to be longer at the equator than at high latitudes (111.9 km and 110.6 km). This can only happen if the Earth is compressed at the poles and is not a ball, but a body close in shape to spheroid. At the spheroid polar radius less equatorial(for the terrestrial spheroid, the polar radius is shorter than the equatorial one by almost 21 km).
It is useful to know that the great Isaac Newton (1643-1727) anticipated the results of the expeditions: he correctly concluded that the Earth is compressed, because our planet rotates around its axis. In general, the faster the planet rotates, the greater must be its compression. Therefore, for example, the compression of Jupiter is greater than that of the Earth (Jupiter manages to make a revolution around the axis with respect to the stars in 9 hours and 50 minutes, and the Earth only in 23 hours and 56 minutes).
And further. The true figure of the Earth is very complex and differs not only from a ball, but also from a spheroid. rotation. True, in this case we are talking about the difference not in kilometers, but ... meters! Scientists are engaged in such a thorough refinement of the figure of the Earth to this day, using for this purpose specially carried out observations from artificial satellites of the Earth. So it is quite possible that someday you will have to take part in solving the problem that Eratosthenes took up a long time ago. This is something people really need.
What is the best way to remember the figure of our planet? I think that for now it is enough if you imagine the Earth as a ball with an "additional belt" put on it, a kind of "slap" on the equator region. Such a distortion of the figure of the Earth, turning it from a sphere into a spheroid, has considerable consequences. In particular, due to the attraction of the "additional belt" by the Moon, the earth's axis describes a cone in space in about 26,000 years. This movement earth's axis called precessional. As a result, the role of the North Star, which now belongs to α Ursa Minor, is alternately played by some other stars (for example, α Lyra - Vega will become it in the future). In addition, because of this precessional) movements of the earth's axis Zodiac signs more and more do not coincide with the corresponding constellations. In other words, 2000 years after the era of Ptolemy, the "sign of Cancer", for example, no longer coincides with the "constellation of Cancer", etc. However, modern astrologers try not to pay attention to this ...
Therefore, I will talk about what sizes the earth's diameter and equator have. Given, as I said earlier, that the earth's shape is not perfectly spherical, it is customary to consider the equator as a circle. At the equator, the diameter is 12 thousand 756 kilometers, and at the poles, of course, a little less - by 43 kilometers. For example, in 2007 it turned out that since 2000 the diameter of the planet has become smaller by five millimeters.
The circumference of the Earth at the equator is 40,000 km, but how many km will it be if measured through the poles?
It is thanks to the rotation that a bulge around the equator was formed. Based on the premise that the Earth is spherical and the circumference is 360 degrees, find the distance (chord) between two points that are a degree apart and multiply by 360. Simple? The length of the equator was calculated by scientists using the formula 2πR, despite the fact that the Earth is not spherical, but elongated in the form of an ellipse (a ball flattened at the poles).
What is the length of the Earth's equator?
40,075 kilometers is the length of the equator. The equator divides the surface of the globe into the northern and southern hemispheres and serves as a reference point. geographical latitude. This is an imaginary line that runs along the surface of the Earth in a plane passing through its center and perpendicular to the axis of rotation of the planet. However, reaching the border between the Northern and Southern hemispheres still did not allow us to determine what the length of the equator is. By measuring the time it took the sun's rays to reach the bottom of the well, the scientist was able to calculate the radius of the globe and find out how long the equator was.
As a result of internal processes in the bowels of the planet, the core gradually warms up and hydrogen is released. This theory, among other things, makes it possible to explain the mass extinction in a short period of time of many species of ancient animals, the so-called Triassic massacre. So over time, the length of the equator will increase.
What is the circumference of the Earth in kilometers - how was this value calculated? What is the circumference of the earth along the equatorial line or along the meridian? This is a circular line encircling the planet and passing through its center. The equator is perpendicular to the earth's axis of rotation. The scientist measured the angle and found that its value is 1/50 of the whole circle, equal to 360 degrees. It turned out that at the equator the degree has a shorter length. Thus, they found out that the polar circumference of the Earth is less than the circumference along the equator by 21.4 kilometers.
What is the size of the circumference of the earth
Who among us will remember how many kilometers the circumference of the Earth along the equator contains? Who knows when and how the circumference of the earth was first measured? By measuring this angle with astronomical instruments, the scientist found that it is 1/50 of a full circle. Thus, it is sufficient to know the chord of an angle of 1 degree (i.e., the distance between points on the surface of the Earth lying on rays with an angular distance between them of 1 degree).
The equator line is perpendicular to the axis of rotation of our planet and is at an equal distance from both poles. This helped him calculate the length of the radius of the Earth and, accordingly, the equator, thanks to the formula for the circumference of a circle. In addition, in other articles, Eratosthenes calculated the Equator using the angle of the shadow when the Sun illuminated the bottom of the well!! 1. A line passing along the surface of the Earth (equator) cannot pass through the center of the Earth, as you have written.
Eratosthenes allegedly measured angles with an accuracy of arc seconds and the difference in the latitudes of Alexandria was 7 ° 6.7 ′, that is, 7x60 \u003d 420 + 6.7 \u003d 426.7 nautical miles (minutes of arc). It is not clear what stage Eratosthenes used to measure distances, etc. The first angle rests on an arc from the end of the gnomon's shadow to its base, and the second - on an arc with a center in the center of the Earth, drawn from Syene to Alexandria. These arcs are similar to each other, since they are based on equal angles. And what does the arc on the bowl have to do with its circle, so does the arc from Syene to Alexandria.
Measuring the circumference of the earth
Here is a simple way to measure the circumference (and diameter) of the Earth, which was most likely used by ancient astronomers. The ideal choice would be a star that is close to the celestial axis North Pole(indicating the center of the Earth's axis of rotation). The angular diameters of the Moon and the Sun are almost the same: 0.5 degrees. If one of our astronomers made this measurement from a location at point (A) near Giza (30 0 C), the star Mizar should have appeared about 41 degrees above the local horizon.
The total length of this arc exceeded 2800 km. It covered more than 25 degrees, which is almost 1/14 of the earth's circumference. Clairaut's theorems establish a connection between the shape of the Earth, its rotation and the distribution of gravity on its surface, thereby laying the foundations for a new direction of science - gravimetry. Geoid is a conditional surface of equal potential (equilibrium surface), coinciding with the surface of freely resting water in the open ocean. Obviously, the relief of the lithosphere in the oceans is located below the surface of the geoid, and on the continents - above (they say: "height above sea level").
Quite recently, in 1862, the German scientist P. Ioseliani, when determining the "depth of the thickness of the globe", obtained 4536.8 km, which is 11/2 times less than the actual value. It is hard to believe, but back in 1876 a pamphlet was published in St. Petersburg entitled: “The Earth is motionless, a popular lecture proving that the globe does not rotate either around its axis or around the Sun. In 1841, the German astronomer F. Bessel, using degree measurements, calculated the radius of the Earth and its compression at the poles, that is, he obtained figures characterizing the main elements of the earth's ellipsoid. We also have to assume that the northern and southern hemispheres, as shown by the Russian scientist A. A. Ivanov, are not completely symmetrical with respect to the plane of the equator.
In size, it surpasses only Mercury, Mars and Pluto. When the area around the North Pole is facing the Sun, it is summer in the Northern Hemisphere and winter in the Southern Hemisphere. When the area around the South Pole is facing the Sun, the opposite is true. Meridian - half of the circle, corresponds to _______ degrees and ________", category "geography".
Of course, as a result of such studies, Eratosthenes calculated the approximate length of the Earth's radius, and hence the equator. To calculate the earth's equator, you need to know the radius of the planet. At the equator, latitude is zero. The length of the equator is one of the main characteristics of any planet.
The Earth's magnetic field in the first approximation is a dipole, the poles of which are located near the geographic poles of the planet.
21.3 kilometers - the equator is farther from the center of the Earth than its poles. Due to rotation, the globe is flattened from the poles by 1/298 of its diameter. 35,786 kilometers - at such a height above the equator, a geostationary orbit is located, on which communication satellites "hang". A signal at the speed of light travels back and forth in just a quarter of a second.
Due to the tilt of the earth's axis, the height of the Sun above the horizon changes throughout the year. For the Earth, the radius of the Hill sphere (the sphere of influence of the earth's gravity) is approximately 1.5 million km [comm. 5]. it maximum distance, on which the influence of the Earth's gravity is greater than the influence of the gravity of other planets and the Sun.
To measure the zenith distance of the Sun, Eratosthenes used a sundial, the skafis, as a goniometer. The sun is 47 degrees 42 minutes.
In other words, the meter was defined as 1/10, 000000 of the distance from the Earth's equator to the North Pole measured along the surface of the circle (ellipsoid) of the Earth through the longitude of Paris.
Like all planets solar system The earth has a spherical shape. Before talking about its exact dimensions, let's introduce some important geographical concepts.
The earth revolves around an imaginary straight line - the so-called earth's axis. The points of intersection of the earth's axis with the earth's surface are called poles. There are two of them: North and South. The line of intersection of the surface of the globe with a plane passing through the center of the Earth perpendicular to the earth's axis is called equator. Planes intersecting the earth's surface parallel to the plane of the equator form parallels, and the planes passing through two poles - meridians.
Due to rotation around its axis and the resulting centrifugal force, the Earth is slightly flattened at the poles and its semi-major axis (equatorial radius, r c) is almost 21.4 km greater than the distance from the center of the Earth to the poles. Such a ball flattened at the poles is called spheroid or ellipsoid of revolution.
In Russia, F. N. Krasovsky's ellipsoid is used for geodetic and cartographic work (named after the scientist under whose guidance the calculations were carried out). Its dimensions are:
- equatorial radius - 6378.2 km,
- polar radius - 6356.8,
- meridian length - 40008.5 km,
- equator length - 40075.7 km,
- the surface area of the Earth is 510 million km 2.
In reality, the figure of the Earth is even more complicated. It deviates from the regular shape of a spheroid due to the inhomogeneous structure of the interior and the uneven distribution of mass. True geometric figure The earth is called geoid("earthlike"). A geoid is a figure whose surface is everywhere perpendicular to the direction of gravity, i.e. plumb.
The surface of the geoid coincides with the level surface of the World Ocean (mentally extended under the continents and islands). The rise and fall of the geoid above the spheroid is 500-100 m.
The physical surface of the Earth, complicated by mountains and depressions, does not coincide with the surface of the geoid, retreating from it for several kilometers. Gravity is constantly striving to level the surface of the Earth, to bring it into line with the surface of the geoid.
