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Anonymous users2024-02-12The earth we live on does not shine in itself. The light and heat on the earth are mainly due to the fact that the sun is shining, and the hemisphere where the sun shines is daytime, and the place where the sun does not shine is night. The earth is a sphere, which constantly rotates from west to east around the earth's axis, which is called the rotation of the earth.
In this way, the part of the earth that receives the sun's heat is constantly changing. The part that gets the heat of the sunlight is constantly changing, and it is not.
The part of the light and heat to the sun is also changing, causing a constant alternation of day and night. When children face the sun, your face is day, the back of your head is night, at this time, your nose is noon, your right ear is morning, and your left ear is evening. As it rotates to the left, the left hand enters the night, the nose enters the evening, and the right ear becomes the noon ......When your face is facing the sun, a day and night pass.
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Anonymous users2024-02-11Because the sun can only shine on half of the earth, and the other half is blocked by the opaque earth, so the illuminated half is day, and what is not illuminated is night, and because the earth has a rotation, so the day area and the night area move to form each place has a night alternation, if there is no rotation, one day and one night is a year, because after all, there is still a revolution (the earth revolves around the sun).In that case, most living beings, with current technology, estimate that human beings will press a mirror in the sky to make the mirror rotate around the earth to achieve the purpose of short-term alternation of day and night.
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Anonymous users2024-02-10The distinction between day and night that people see is due to the rotation of the earth. The Earth is a non-luminous and opaque sphere that rotates, so at any one time, the Sun can only illuminate half of the Earth's surface. Half of the world illuminated by sunlight is day, and half of the world that is not illuminated by sunlight is night.
Since the Earth's axis is tilted, the length of day and night varies in different parts of the Earth.
The cycle of day and night, which is the time interval between the sun passing through the same meridian twice in a row, is called a solar day. The solar day restricts human daily life and rest, so it is used as the basic unit of time. In addition, the short duration of the solar day prevents the entire Earth's surface from heating and cooling too violently, thus ensuring the survival and development of living organisms on Earth.
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Anonymous users2024-02-09Because the earth rotates.
The discovery of the phenomenon of day-night depends on Copernicus's heliocentric theory: the earth revolves with the sun and rotates at the same time, which is a reasonable explanation for the phenomenon of day-night. 300 years after the heliocentric theory was proposed, a scientist named Foucault discovered the law of motion of the pendulum, which provided strong evidence for the heliocentric theory.
The earth rotates at the same time, and it takes 23 hours, 56 minutes and 4 seconds to rotate around in one revolution, and the revolution is about a degree, which is equivalent to 3 minutes and 56 seconds according to the speed of the earth's rotation, and the time, rotation plus the time taken to rotate is 24 hours. Longitude is every 15 degrees, and local time is one hour apart.
You're going to have to read a geography book for this, hehe. Let's talk about it in layman's terms: the earth revolves around the sun, based on the earth's axis, the earth is relatively inclined to the sun, so the distance from the sun to the earth is different, when the northern hemisphere is close to the sun, it is the summer of the northern hemisphere, on the contrary, the southern half is farther away from the sun, that is, winter, according to these, it can also be inferred that when the northern half is close to the sun, the northern half of the sun is illuminated in a large range, the days are long and the nights are short, and even the north pole will appear polar day, 24 hours are day, and the south pole is night for 24 hours. >>>More
It depends on the time. At the spring and autumn equinoxes, the sun shines directly on the equator, and the global equinox of day and night. From the spring equinox to the summer solstice, the direct point of the sun begins to move north, and the days in the Northern Hemisphere gradually become longer. By the time of the summer solstice, the daylight hours are the longest, and the sunrise in the northeast is just after 4 o'clock. >>>More
The rotation of the earth produces a diurnal cycle; The Earth's revolution produces seasonal changes. Since the earth is an opaque planet, the sun and stars give the earth light, and the side that shines on the sun is day and the other side is night. The earth is constantly rotating from west to east around its axis of rotation, and the phenomenon of celestial bodies rising in the east and setting in the west is a reflection of the earth's rotation. >>>More
It is the result of the rotation of the earth around the sun. The side facing the sun is day, and the side facing away from the sun is night.
Squid, octopus, cuttlefish, portionalAmphibiansandChameleonand so on can change color in the blink of an eye because they have a brain-independent photoreceptor that belongs to a family of proteins called opsin. >>>More