"One day in heaven, one year on earth"

"A day in heaven and a year on earth", meaning that a day spent in heaven and a year spent on earth, we generally think that such a situation will only appear in those ancient legends, but in reality, this is not the case, because according to the theory of relativity proposed by Einstein, the passage of time is not constant.

Einstein pointed out that the faster an object is, the slower the time it experiences, and when an object is in the middle of a gravitational field, the stronger this gravitational field is, the slower the time it experiences.

This phenomenon of time slowing down is called "time dilation", in the past, scientists have long confirmed the existence of this phenomenon through a variety of methods, in fact, we often use the satellite positioning system, it must be based on the theory of relativity to exclude the "time dilation "Otherwise, every 12 hours, its positioning results will have a deviation of about 7 meters.

Therefore, it can be said that "a day in the sky and a year on earth" is Einstein's theory, which can be interpreted as the time dilation in the "sky" compared to the "earth" We can interpret this as the time in "heaven" has expanded by about 365 times compared to "earth". But the problem is that Einstein proposed the theory only after the 20th century, which belongs to modern physics, but how could the ancients know it?

Why did the ancients say "a day in the sky and a year on earth"? Did the ancients also understand relativity?

There is a very interesting speculation that the universe is so large and has existed for so long that it is not impossible for there to be advanced civilizations with highly developed technology.

If there is an advanced civilization, they should have mastered the technology of high-speed flight in the universe, and even have the ability to extract energy directly from a black hole, and according to Einstein's theory, whether it is a high-speed flight in the universe or the strong gravitational field near the black hole, there will be a very obvious "time dilation".

Therefore, reasonable speculation is that the ancient legendary "immortals" may be the advanced civilization, perhaps in the distant past, there are advanced civilizations once visited the Earth and told the ancients about the phenomenon of "time dilation". As the ancients believed that "gods" were from the sky, the ancient legends have a "day in the sky, a year on earth" description.

Of course, this speculation can only be said to be impractical and whimsical, after all, the so-called advanced civilization is only a nebulous existence, so is the actual point, and how should be explained?

The reason why the ancients would think that the "sky" time passes more slowly than the "earth", is likely to be related to the stars in the sky.

For the definition of the unit of time "days", I believe that many people will think that the Earth's rotation is one day, but this is not the case, because the Earth's rotation period is about 23 hours, 56 minutes, and 4 seconds, and we all know that the time of day is 24 hours, which is more than the Earth's rotation period is about 3 minutes and 56 seconds. Why is this so? Let's see.

The modern human definition of the unit of time "day" is the time interval between two consecutive passes of the sun over the same meridian, while for the ancients, the time interval between two consecutive passes of the sun over the midheaven at the same location is a day (which is the same thing).

As shown above, the Earth is still rotating around the Sun at the same time as it rotates. In position 1, the Sun is just located in the observer's midheaven, and when the Earth runs to position 2, the Earth just completes a rotation (at this time, about 23 hours, 56 minutes, and 4 seconds have passed), and at this time, the Sun is not located in the observer's midheaven, so the Earth has to turn a little more time before the Sun will At this time, the Sun is not in the observer's midheaven, so the Earth has to rotate a little more before the Sun is in the observer's midheaven, and this "little time" is about 3 minutes 56 seconds.

On the other hand, since the other stars in the universe are so far away from the Earth that the Earth's rotation has a negligible effect on their position in the sky, the time interval between two consecutive passes of these stars over the same meridian can be considered as the rotation period of the Earth.

This means that if observed at the same location on Earth, the same layout of stars in the sky would appear about 3 minutes and 56 seconds earlier than the previous day, and 3 minutes and 56 seconds earlier in a day, and almost two hours earlier in a month, which is an hour for the ancients.

Considering that the ancients were usually fond of observing the stars in the sky at night (after all, there was no electricity back then), it is reasonable to believe that the ancients would easily find that the star layout they saw on that day would always appear about one hour earlier than the same day of the previous month.

In this case, the ancients would probably have thought that the stars in the sky had gone only one hour (two hours), and a month had passed on the ground so that the conversion would be exactly "a day spent in the sky, and a year spent on the ground".

In other words, although the ancients said "a day in the sky, a year on the ground" in line with Einstein's theory, this is just a coincidence, and the reason why the ancients would have such a view should be through the observation of the stars in the sky change speculative results, as, for the theory of relativity, the ancients should not understand. Of course, this is also just speculation, only relatively reasonable a little.