Why does the earth produce time difference, and the error of the earth s rotation time

It's jet lag...

As the earth rotates, the sun rises in the east and sets in the west during the day, and the sun passes through the highest point in the sky at 12 o'clock in this place, so there are different places on different meridians. The same time used in the same time zone is regional time (local time on the ** meridian of the region) and the same time used worldwide is universal time (local time on the 0th meridian). The longitude varies by one hour every 15 degrees in regional time and every 4 minutes in local time and longitude every 1 degree.

The standard time for all locations is Greenwich Mean Time (plus ( + or minus ( - time difference for the number of hours and minutes marked in the time zone. Many countries also use daylight saving time (DST), such as the United States, which runs from April to September, an hour earlier.

The calculation method of time difference: the subtraction of the standard time (the number of real-time zones) of the two time zones is the time difference, and the time when the value of the time zone is larger is earlier. For example, China is the East 8th Zone (+8), and the East of the United States is the West 5th Zone (-5), the time difference between the two places is 13 hours, and Beijing is 13 hours earlier than New York; If it is a period when daylight saving time is implemented in the United States, the difference is 12 hours.

Jet lag is due to the fact that the earth is a sphere, and the sun shines at the same angle at different diameters, such as the time overhead (noon occurs during a long flight by plane). For example, Beijing departs for Europe at 7 o'clock in the morning, after 12

Because we use the solar day instead of the sidereal day. A solar day is equal to the time it takes for the Sun to pass the highest point in the sky twice in a row at the same location (24 hours), and a sidereal day is equal to the time it takes for a particular star at the same location to pass the highest point in the sky twice in a row (i.e., the time of the Earth's rotation, which is 23 hours, 56 minutes, and 4 years). The difference between the two is 3 minutes and 56 seconds.

The reason for the difference is that after the earth has rotated for 1,365 years at the same time as it has rotated once, then after the earth has made a full revolution, the sun will not return to the highest point of the same place (fiddling with the globe will understand), but the earth must turn another 1,365 arcs to make the sun return to the highest point of the same place again. That is, each time the Earth needs to rotate 2 (1+1 365) arcs for the Sun to pass the same altitude at the same place again. This increased time of 1 365 in 24 hours, is exactly equal to 3 minutes and 56 seconds.

The reason why we can't feel this time difference is because the most sensitive celestial body of human beings is the sun, and as long as the sun comes to the same place again, we naturally feel that it is exactly one day, and as for the fact that the earth has actually rotated 1,365 times more during this time, it is difficult for human beings to feel it.

However, astronomers who have been observing distant stars for a long time can still find that the time for stars to appear in the same position is 2 hours earlier each month, and the star that appears in the east in the spring evening may appear in the west, in the fall, and that it can be seen in the east the following spring night.

Four years run once a year (365 days, 5:48:46 seconds), four years later, the remaining time is 23:15:4 seconds, the number of days becomes 366 days, so the time is added by 44 minutes and 56 seconds (3 4 time difference 4 seconds), if there are 100 leap years in 400 years, then the time is added by 3 4 * 100 hours - 4 * 100 seconds (3 days, 2 hours, 53 minutes and 20 seconds), so there are 97 leap years in 400 years, which is only a rough calculation.

Your question is interesting and worth looking into.

The division of time zones: the world is divided into 24 time zones according to longitude, each time zone spans 15° longitude, based on the prime meridian, and the range of east and west longitude is as the zero time zone (also called the middle time zone), and then every 15° is a time zone. The time zone east of the zero time zone is the eastern time zone, which is divided into the east zone 1 - the east 11 zone; The time zone west of the zero time zone is divided into one west zone - the west eleventh zone, and the east twelve and west twelve zones each occupy a longitude, that is, each is half a time zone, so the two are combined into a complete time zone, called the east and west twelve zones, and the world is divided into 24 time zones.

As the Earth rotates from west to east, from zero hour to east, the time increases by one hour for each additional time zone, and decreases by one hour for each additional time zone to the west. The West 12th District has 24 hours less time than the East 12th District.

Time is gone, time is unidirectional, so time cannot be the same, that is, the difference in time is absolute, the season is just a natural law of periodic changes, it is determined by the distance between the sun and the earth, the distance between the sun and the earth changes periodically, so there is a periodic change of the season.