Why is there a precession? What is precession?

Precession, in astronomy, refers to a slow and continuous change in space caused by gravity on the axis of rotation of a celestial body. Yu Xi, an astronomer of the Jin Dynasty, discovered the precession and calculated that the winter solstice recedes one degree after every 50 years, which was a leading position in the world at that time.

The discovery of precession and the calculation of accurate values are of great significance to the formulation of China's calendar. Later calendars have introduced this achievement, making the precession value in our calendar more and more accurate.

Precession is the time difference between the return year and the sidereal year.

precession definition; The year is the year, and the precession is the time difference between the return year and the sidereal year.

It is the differential rotation of the earth that shortens the time of the return year, resulting in precession.

It's the age difference between people of different ages.

The ancient Greek astronomer Hipparchus described the phenomenon of precession by saying; The ecliptic longitude of all stars changes significantly (eastward), while the ecliptic latitude does not change at all. There are significant changes in the interpretation of precession by the precession of the earth axis, and the yellow longitude and latitude are obviously incorrect.

precession solution precession test of the earth axis;

Only the precession of the Earth** is consistent with the ancient Greek astronomer Hipparchus's description of the phenomenon of precession.

The age difference refers to the age gap between two people. The "age difference" is usually used to refer to the age gap between the couple, while the "optimal age difference" refers to the age gap between the couple and the couple, which is about 3-7 years old, and the children born to couples in this range will be smarter and will live happier lives. Many couples are a combination of "old husband and young wife", of course, their age gap is not very large, generally 3-7 years old.

The effects of different age differences in the familyWhen the age gap between siblings is three years or less, they tend to play well together and have a lot of interaction. As adults, children feel stronger bonds and are more intimate.

When the sibling age difference widens to over 4 years of age, the children interact significantly less than the children with the age difference within the age of 3 years, and the children interact less as they get older.

Couples with a large age difference may be at risk of:

Differences in lifestyles and values: Due to differences in age and upbringing, the lifestyles and values of the two people may be different, which can lead to difficulties in communication and getting along.

Differences in social status and life stages: If two people are at different stages of life and social status, there may be a lack of synchronization in career development, life goals, life experiences, etc., which may lead to conflict and dissatisfaction.

Differences in health status: Couples with a larger age difference may differ in terms of health, and older people may have more health problems and need more care and attention, which can be stressful for younger partners.

In view of the above risks, couples can consider the following ways to deal with them:

Respect each other's differences: Couples need to respect each other's differences, including differences in lifestyles, values, and goals. Through communication and understanding, let each other get to know each other better.

Focus on health: Couples need to pay attention to each other's health, and younger partners need to focus on the health of the elderly, providing the necessary care and attention.

Good communication and negotiation skills: Couples need to have good communication and negotiation skills, manage differences and conflicts with each other, and avoid emotional tension and unpleasant situations.

In the case of a large age difference, there may be some risks and challenges in the future, mainly including the following aspects:

1.Differences in life values: Due to differences in age and growth experience, there may be large differences in the life values of the two parties, which can lead to difficulties in communication and exchange, and even mutual exclusion.

2.Differences in living habits: Couples with large age differences may have different living habits, such as meal times, sleep habits, entertainment preferences, etc., if they cannot be coordinated, it may lead to uncoordinated lives and even conflicts.

3.Phased differences: In terms of emotion, career, and life, couples with a large age difference may be at different stages, such as studying, starting a business, and laughing at family life, etc., each stage has its own needs and pursuits, and if it is difficult to understand and support each other, it will lead to conflict.

4.Social recognition is not obvious: Although it is now common for couples with large age differences, there are still some concepts and prejudices in society, which brings certain pressure and distress to couples.

How can these challenges be addressed?

1.Respect each other's life values: Both parties need to respect each other, understand each other's life values, maintain open communication and exchanges, and avoid estrangement.

2.Coordination of living habits: Coordination, compromise and adaptation to each other's living habits to establish a good and adaptive lifestyle.

3.Understand each other's stage pursuits: The other person's stage of life will bring about some specific needs and pursuits, and we need to support and encourage each other to get through the stage difficulties together.

4.Build a stable and healthy relationship: On the basis of building a stable relationship, we will understand, tolerate and support each other, and continue to strengthen and maintain each other's ability to cooperate and deal with problems.

The age difference is not a certain limit, but more important is mutual understanding and communication with each other, as well as a common vision for the future, and how to create a healthy and stable emotional foundation to adapt to future challenges.

As we all know, the gyro almost does not rotate completely parallel to the ground, and will shake up and down or even stop due to the gravitational imbalance on both sides of the top. The earth is similar to a spinning top, it rotates around the earth's axis, and the direction of rotation will not be fixed for some reason, which causes "age chips". To put it simply, precession is the phenomenon of the displacement of the vernal equinox caused by the precession of the earth's axis of rotation.

Under the gravitational forces of the sun and the moon, the spatial orientation of the earth's axis of rotation is not stable, and while moving around the center of the earth, the axis perpendicular to the ecliptic plane is also moving slowly and continuously, and from the northern hemisphere, about 25,800 years clockwise (from the northern hemisphere) rotates once (from the northern hemisphere), depicting a cone. This also causes the vernal equinox to rotate once every 25,800 years along the ecliptic, and in the opposite direction of the sun's annual apparent motion, moving westward approximately each year. This long-term precession (or precession) of the Earth's axis is called the precession of the sun and the moon because it is caused by the sun and the moon.

In addition, the planet also has a certain gravitational effect on the Earth, which causes the Earth's orbital plane to constantly change its position, which not only changes the angle of the yellow and red cross, but also causes the vernal equinox to produce a small displacement along the equator, in the opposite direction to the precession of the sun and the moon, this effect is known as the planetary precession. The precession of the planets causes the vernal equinox to move eastward along the equator about annually. If the precession of the sun and the moon and the precession of the planets are combined, the coordinates of celestial bodies such as right ascension and red tail will change, and we call the amount of change in a year annual precession.

In addition, according to the general theory of relativity, the axis of rotation of a rotating object such as the Earth also produces relativistic precession in a narrow space, called geodetic precession. The geodetic precession of the Earth is. The Earth's orbit "ecliptic" does not coincide with its equator, and we call the point where they intersect the vernal and autumnal equinoxes.

The time when the sun returns from the vernal equinox to the vernal equinox is represented by the return year.

Because of precession, individual celestial bodies change over time. It is speculated that in 10,000 years, Vega will become the North Star. Because of the precession, the 12 zodiac signs of the zodiac in ancient Greece have increased by one ophiuchus to 13.

In addition, the intercalation of the year in the solar calendar is also related to the precession.

Precession refers to the phenomenon that the long-term precession of the Earth's axis of rotation causes the vernal equinox to move westward along the ecliptic, resulting in a return year shorter than the sidereal year. The reason for this is that the Earth is an ellipsoid, and the equator is partially uplifted; The equatorial plane does not coincide with the ecliptic plane. The Sun, Moon and other planets exert additional gravitational pull on their equatorial uplifts, causing a change in the tendency of the equatorial plane, i.e., precession of the Earth's axis.

As a result, the vernal equinox moves westward along the ecliptic by about 50 per year2. About 26,000 years to move a week. It makes the return year slightly shorter than the sidereal year, which was called "precession" in ancient China.

It is only due to the action of the sun and the moon that the westward shift of the vernal equinox does not change the angle of the yellow and red equinox, which is called "the precession of the sun and the moon". The action of other planets changes the yellow-red angle at the same time, which is called "planetary precession". The sum of the two is called "total precession."