Here's a beautiful folktale:
The Jade Emperor had a granddaughter who was called a weaver girl because she was good at weaving cloth. Tired of the life of the gods, the weaver girl secretly went down to the mortal world, fell in love with the industrious and simple peasant Cowherd, and lived a happy life of male and female weavers (the cowherd pig is considered to be the cabbage in the sky). Later, when the Jade Emperor heard about it, he was furious and sent someone to arrest the Weaver Girl back to the Heavenly Palace. When Niu Lang caught up, he was blocked by a galaxy drawn by the Queen Mother in the sky.
Since then, the cowherd and the weaver girl have lived a long-term separation. Their unwavering love touched the magpies. Every seventh day of July, magpies build a magpie bridge over the Milky Way for the cowherd and the weaver girl to meet once. This is the story of the cowherd weaver girl Queqiao meeting.
Cowherd and Weaver Girl, although they are fictional characters, there is really a Vega star and a cowherd star in the vast starry sky. Modern scholars have argued that the ancients watched the sky at night, and gradually derived the story of "Cowherd Weaver Girl" from the distant view of Vega and Cowherd Star.
Located about 25 light-years from Earth, Vega is the brightest star in the constellation Lyra. Summer is here, and we can observe Vega directly with the naked eye in the Northern Hemisphere. So Vega was honored as the "Queen of Summer Nights". Vega is about 455 million years old, much younger than Earth (Earth is 4.55 billion years old). However, Vega has a large mass, at 2.135 M⊙, which is equivalent to 2.135 suns. In addition, Vega is 3.2 times the diameter of the Sun, 33 times the volume of the Sun, and 1.5 times the surface temperature of the Sun.
Thus, Vega is not only a big man, but also a passionate "beauty" if we think of her as a woman.
The star belongs to the constellation of Aquila, and its official name is "Aquila α". Like Vega, he is a young star. It is 1.7 times more massive than the Sun, 1.8 times its diameter, 10.6 times brighter than the Sun, and 1.2 times warmer than the Sun.2.
In comparison, The Cowboy star is slightly smaller than Vega, but brighter. On summer nights, when we are outdoors, it is easy to find the cowherd star and vega star overhead.
However, it is not easy for the cowherd and the weaver girl to meet once. Because, they are too far apart.
Astronomically , the star is 16.4 light-years away from Vega. 1 light-year is about 9,460 billion kilometers, and 16.4 light-years is about 1551440 billion kilometers.
In folk tales, cowherds and weavers lived in ancient China, when there was no modern means of transportation, and they all relied on walking. According to the walking speed of ordinary people, cowherds and weavers walk in opposite directions, can walk 5 kilometers per hour, and can walk about 86,400 kilometers a year. With that said, it would take about 1.8 billion years for the cowherd and the weaver girl to meet.
Weaver Girl is an immortal god who is naturally not afraid of the passage of time. But Niu Lang is a common man, can he live that long?
It seems that if the cowherd weaver girl wants to meet, she cannot rely on walking, but must use more advanced means of transportation. Let's simply imagine that the cowherd and the weaver girl live in modern society and take a plane to meet each other, so it's always okay, right?
Currently, the fastest flying aircraft in the world is a rocket-powered experimental aircraft X-15A, which was developed by North American Airlines. On October 3, 1967, U.S. Air Force Major William Knight flew the X-15A-2 test aircraft to 7272 km/h (6. Mach 72), the fastest ever reached by any aircraft.
If the cowherds and weavers were all riding in an X-15A-2 test aircraft, they could fly about 127 million kilometers a year, and it would take about 1.22 million years to meet.
It seems that it is not okay to meet each other by plane. Are there any faster flying machines?
Yes. On August 12, 2018, NASA launched a solar probe called Parker, the fastest flying vehicle in human history, and at 4:37 on January 29, 2020, the Parker solar probe flew at a speed of more than 393,000 kilometers per hour, about 321 times the speed of sound, when it completed its fourth recent intreom flight.
If the Cowherd Weaver girl went to meet in the Parker Solar Probe, they would travel in opposite directions and fly about 6.9 billion kilometers a year, so that it would take 22,500 years to meet.
Obviously, it is really too difficult for the cowherd weaver girl to use our human means of transportation to meet. So, can you use the identity of the Weaver Girl as a god to learn faster flying skills - such as Sun Wukong's Douyun?
"Journey to the West" records that Sun Wukong's Douyun is the first flying technique between heaven and earth, and one heel can go 108,000 miles. We imagine that Sun Wukong spends 1 second on a heel, 54,000 kilometers in 1 second, reaches a speed of 190 million kilometers per hour, and can run 1,664.4 billion kilometers per year. If the Weaver Girl alone learned to fight the clouds, it would take 93 years to see the side of the cowherd; if the cowherd also learned, the time they would meet would be reduced to 46.5 years.
Look, even the cowherd weaver girl has learned to fight clouds, and she can't meet once a year. In fact, even if they were moving at the speed of light, it would take more than 8 years. It's too hard. Therefore, the cowherd weaver girl still maintains a long-distance relationship, "if the two loves are long, they are in the twilight of the dynasty."