Sun Wukong, also known as Brother Monkey, is definitely a household name. Sun Wukong in "Journey to the West" learned a very powerful flying technique from Bodhi Laozu - The Spreading Wings, which can be summoned by flipping a heel when used, and can go to a place 108,000 miles away in a single thought.
Monkey brother uses tendons to fight clouds, and does not need to be flipped over and over, and the follow-up only needs to be set up to fight clouds, and you can reach the place you want to reach with your heart. One hundred and eighteen thousand miles, converted into the current unit, is 54,000 kilometers. Sitting on the ground for 80,000 miles a day, that is, the circumference of the earth's equator is about 40,000 kilometers, that is, brother monkey can reach any place on the earth in a single thought. In ancient times, this was unthinkable.
Wu Cheng'en, the author of the novel, also did not explain how fast The flying speed of Douyun was. If you think about it for 108,000 miles, then think that you can fly 54,000 kilometers per second.
Goku once teased the Seven Fairies in the Peach Orchard. In the vast expanse of the universe, there is a galaxy called Andromeda. When Goku heard about it, he wanted to go to the fairies to reminisce about the past, so he set up a douyun and left. So when will he reach the Andromeda galaxy?
In fact, the Andromeda galaxy does not have fairies, but a galaxy of at least 1 trillion stars, a galaxy similar to the Milky Way where The Earth's sun is located. The Andromeda Galaxy is a spiral galaxy with a massive disk-like structure, about 220,000 light-years in diameter, larger than the Milky Way. The Andromeda Galaxy is one of the few galaxies visible to the naked eye in Earth's night sky and is one of the farthest objects visible to the naked eye on Earth.
To know how long it will take for Sun Wukong to reach the Andromeda galaxy, we must first know how far it is from us.
Astronomers have measured the Andromeda Galaxy about 2.54 million light-years from Earth through astronomical observations.
How did this distance come about? There are many ways to measure.
A relatively distant object like a galaxy can measure the spectral redshift of the galaxy and derive the distance according to Hubble's law; in addition to this method, there is a special class of variable stars in some galaxies - Cepheid variables, cepheid variables are known as measuring scales because their light period is proportional to the luminosity, according to which distance can be measured. For some stars that are relatively close to us, we can use the trigonometric parallax method to measure the distance, the basic principles have been learned in junior high school; for some more distant stars, the previous method is not applicable, but by analyzing the spectrum of the star, according to the physicochemical properties, inferring its absolute magnitude or luminosity, and using the actual observed apparent magnitude to calculate its approximate distance from us.
Okay, back to the point. 54,000 kilometers per second, which is more than 1/6 of the speed of light (300,000 kilometers per second), but this speed is really not enough to look at in the universe. Even at the speed of light, it is not enough to look at in the universe, and it is very slow. Because even if you fly at the speed of light to proxima centauri, the closest star to Earth, it will take 4.2 years.
The Andromeda galaxy is 2.54 million light-years away from Earth, which means that it would take 2.54 million years to travel at the speed of light. If Sun Wukong had driven the Douyun, it would have been even slower, about 14.11 million years.
The universe is expanding, so why not consider the effects of the expansion of the universe here?
For every 3.26 million light-years (million parsec Mpcs) increased in distance between objects, the speed of distance between them increased by about 67.8 km/s. The Andromeda Galaxy is located 2.54 million light-years from Earth, and for these two very large galaxies, gravity prevails at such scales. Observations suggest that the Andromeda Galaxy is one of the few galaxies with a blue shift in the spectrum, as it is approaching the Milky Way at a speed of 110 kilometers per second under gravity and will merge with the Milky Way into one larger galaxy in billions of years.
Obviously, 14.11 million years is a high valuation. However, the speed at which the Milky Way and the Andromeda galaxy are getting closer to each other is not fast, and Sun Wukong also arrived in the Andromeda galaxy tens of thousands of years earlier than this.
Such a long time is unimaginable to mortals on earth. Because even if you fly for 50 years with a tendon bucket, you can only fly about 9 light years. In the Xiu Xian novel, it took most of his life to just come out of the novice village, and he had never seen it in the world, but people were already old.
Fortunately, Sun Wukong jumped out of the cracks in the stone, and Shou and Tianqi could rush to the Fairy Galaxy without eating, drinking, and sleeplessly, because time is infinite for Goku. It's just that this road is very lonely, and Goku is probably unbearable.
Everyone knows so much, and they don't hurry to persuade Sun Wukong to give up the idea of going to the Andromeda galaxy to see the fairies.
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