Whether the sun is near the earth in the morning or at noon

The sun is the same distance from the earth in the morning and at noon. Why does the sun look bigger in the morning than at noon? It's a visual error, an illusion.

The same object, placed in a group of objects larger than it, appears small, while placed in a group of objects smaller than it appears large. In the same way, the morning sun rises from the horizon against the backdrop of trees, houses, distant mountains and a small corner of the sky, and in this comparison, the sun appears larger. At noon, when the sun rises high and the vast sky is the backdrop, the sun appears smaller.

Secondly, the white part of the same object appears larger than the black one, and this physical phenomenon is called "photoosmosis". When the sun is rising, the background is a dark and dreary sky, and the sun is exceptionally bright; At noon, the background is a blue sky, and the sun does not contrast much with its brightness, so it appears smaller. Q:

Is it cool in the morning? Or is it high at noon? The temperature is higher at noon than in the morning, is the sun closer to us at this time than in the morning?

Neither is it. The main reason is that the sun hits the earth obliquely in the morning and the sun shines directly on the earth at noon. At the same time and in the same area, direct radiation is higher than oblique heat.

At the same time, at night, the heat of the sun shining on the ground dissipates, so it feels cool in the morning; At noon, the heat of the sun hits the ground, so it feels hot. The temperature is hot or cold, and it does not indicate how far or near the sun is from the ground. The Earth's orbit around the Sun is an ellipse with the Sun at one of the focal points.

It passes through perihelion (147.1 million km from the Sun) in early January and aphelion (152.1 million km from the Sun) in early July. It has been calculated that the Earth is about 8,000 kilometers closer to the Sun from morning to noon every year from aphelion to perihelion (July and January), during which the Sun at noon each day is closer to us than the Sun in the morning. Conversely, when the Earth moves from perihelion to aphelion (January-July), the Sun at noon is about 8,000 kilometers away from us every day than in the morning. The difference between the distance between the Sun and the Earth in the morning and at noon is 8,000 kilometers, which is insignificant compared to the average distance between the Sun and the Earth (100 million kilometers), and it is difficult to observe with the naked eye.

If you want to know more about the sun and the earth, I personally recommend that you go to the astronomical forum, the shepherd astronomy forum, and the Tianzhiwen astronomical forum are relatively OK**.

The sun is the same distance from the earth in the morning and at noon.

Earth-sun distance, which has a maximum value of 152.1 million km (the Earth is at aphelion); The minimum is 147.1 million km (the Earth is at perihelion); The average is 149.6 million kilometres; This is an astronomical unit, which was established by the International Astronomical Union in 1976 as 149597870 kilometers and has been in use since 1984. At this distance, it takes only 8 minutes and 18 seconds for sunlight to reach the Earth's surface.

The causes of the earth's seasons are caused by the direct and oblique rays of sunlight. Because there is an angle between the Earth's orbital plane and the Earth's equatorial plane, the northern hemisphere of the earth is tilted towards the sun during the summer solstice, and the sun's rays hit the Tropic of Cancer directly, so the weather in the northern hemisphere is hot. In addition, the speed of the Earth's revolution also has an effect, the Earth's revolution speed is very fast when it passes perihelion, and it is slow when it passes aphelion.

According to Kepler's three laws, the Earth's orbit around the Sun is an ellipse, and the Sun is at one of the focal points of this ellipse. The eccentricity of the Earth's orbit is that there is a perihelion and an aphelion in the orbit. It is 147.1 million kilometers from the Sun at perihelion and 152.1 million kilometers from the Sun at aphelion, a difference of 5 million kilometers, or about 1 30.

But the difference of 1 30 also brings clear benefits to our northern hemisphere. According to the "precession" change, after 13,000 years, this situation will be reversed, with winter in the northern hemisphere passing aphelion and summer passing perihelion. Yuanzhi Cong.

Mercury's perihelion moves in the plane of its orbit, moving forward every 100 years (known astronomically as precession)5601"43 higher than the value calculated according to Newton's laws", which is known as the Mercury perihelion anomaly. In 1859, the French astronomer Urbain Le Verrier, the discoverer of Neptune, was inspired by the discovery of Neptune and boldly proposed that this phenomenon was caused by the perturbation of Mercury by an unknown underwater planet.

The same. The distance between the Sun and the Earth is calculated as the straight-line distance between the center of the Sun and the Earth's center. Thus, on the same day, the distance between the Sun and the Earth can be said to be the same, because in one day, the Earth moves only a small part of the length of 1,365 in its orbit, which is negligible for the change in the distance between the Sun and the Earth.

The distance between the Sun and the Earth, in turn, is an astronomical unit of length, which was once defined by the average distance between the Earth and the Sun, but has now been changed to an absolute distance of 149,597,870,700 meters. Astronomically, this length is determined to be 1AU, i.e. an astronomical unit.