The audience has not yet recovered from the storm, and Bi Fang is about to embark on the journey again, which makes people worry about whether the intensity of the migration is too high.

They still remember the lightning and thunder a few hours ago, and the Huanghuang Tianwei can't be looked at directly, in that case, ordinary people don't even dare to go out, let alone fly the plane through the storm, and the drum washing machine doesn't turn like this.

[Is Fang Shen no longer a man? ] If so, can you pick me up? I don't want to either. 】

[Flying at night, can the geese keep up?] 】

[Yes, if it's not dark, won't something happen? 】

[Just a few hours, can you rest?] 】

"Of course, in fact, most of the geese migrate at dusk or at night, and I chose the day just because it is in line with human habits."

"And don't underestimate the resilience and endurance of geese, they are one of the few birds that can fly across the Himalayas."

Bi Fang pulled the engine, and in the night, the glider swept through the air like a giant black bird, and with it as an eye, eighteen geese were neatly arranged behind him.

"Speaking of which, I rarely rush to the road at night, and when it comes to night, I have to mention the starry sky."

Breathing in the salty vapor, Bi Fang turned the camera to Hoshino, where the endless starry sky swirled above him.

"Thousands of years ago, our ancestors began to use the movement of celestial bodies to determine their bearings, and if you can determine your position by the movement of the sun, moon and stars, then you can find the right direction even without navigation tools."

[I know this, look for North Star!] 】

[And the Big Dipper, I've learned this in kindergarten! ] 】

[Ah, isn't the Big Dipper the North Star......]

[I opened the door and looked, wow, there are no stars!] 】

Due to the time of the live broadcast, the number of people in the live broadcast room has dropped a lot, from more than 200,000 to about 100,000, but the barrage is not less at all, and the enthusiasm of the audience is still high.

Bi Fang estimated that it should be nine o'clock in the evening, and it should be two o'clock in the morning in China, and there are still so many people active?

But people nowadays really lack some common sense, and they can't even tell the difference between the North Star and the Big Dipper.

Bi Fang sighed silently, in fact, he can also understand that people now basically live in the city, at night, the only thing in the sky is the moon, occasionally the clouds are thicker, and even the moon can't be seen, in this case, who cares about the name of the invisible star?

"Don't look at the Big Dipper and Polaris sound like similar names, but they are completely different things, the first is the number, Polaris is the name of a star; The Big Dipper is composed of seven stars, named because the composition is shaped like a bucket, also called the 'Big Dipper'. ”

"Secondly, the two also have different functions, and the North Star can very accurately point the direction of due north; And the role of the Big Dipper is to help us find the North Star. The North Star is just on the extension of the connection of the two stars below it. ”

Bi Fang raised his head to look up at the starry sky, and told some tips for finding and identifying photos, and in the first person, the audience directly followed his perspective to find the so-called Big Dipper.

"Polaris belongs to the constellation Ursa Minor, and it is the brightest of them. However, since all the stars in the constellation Ursa Minor are faint except for Polaris, we usually need to look for Polaris based on the Big Dipper. ”

"And the Big Dipper is the main body of the constellation Ursa Major, located at the tail of the Ursa Major, which is shaped like a spoon. The target range is larger, and it is faster and easier to confirm a single target Polaris. ”

Six of the seven stars of the Beidou are of the 2nd magnitude and 1 is of the 3rd magnitude, which is very easy to identify, especially in an empty and less polluted place like the sea, which is hard to forget after a glance.

The night sky was clear and full of light, as if a traveler had come to a silent moonlit night and found his way home according to God's guidance.

[Damn, I've grown so big, it's the first time I've really seen the Big Dipper!] 】

[Mom, I'm out of breath! 】

Look at your little bit of interest! 】

[Staying up late to see the Big Dipper, it's worth it! ] 】

[Because I often stay up late, my liver doesn't seem to be very good, can you tell me to be careful with my liver? 】

"From the two stars on the side of the bucket, that is, the line of the pole star is extended about 5 times to the outside of the bucket, we can find our target, the most important star in the northern hemisphere, the North Star, see it?"

Bi Fang stretched out his fingers and deflected his gaze along the line, and the audience soon spotted the brightest star in the night sky.

"There's no brighter star in a sizable area near the North Star, so it's very easy to find it this way."

"On the background of the starry sky, Polaris is less than 1° from the North Pole, and when we find Polaris at night, we basically find due north."

With the direction, Bi Fang accelerated the speed of the plane, bringing a gust of wind howling in the sky.

[Wow, it's so bright]

[The brightness is not the same level as other stars at all!] 】

"Of course, Polaris is one of the few first-class stars."

Bi Fang is very happy, and this feeling of sharing the beauty with others is very good, like having teammates by his side in his previous life.

Etienne in the back row was also fascinated by the starry sky, and when he heard the concept of a first-class star, he was curious: "What is a first-class star?" ”

"Ah, this ......" Bi Fang scratched his head, "The brightness of the stars is different, and it has to do with the temperature of the stars, the distance or something, you know this?" ”

"Uh-huh."

According to legend, the ancient Greeks Hipparchus divided the starlight into six levels according to the different levels of brightness, with the brightest of the first magnitude and the darkest of the sixth magnitude. The difference in brightness between stars of each magnitude is about 2.5 times, and in fact, the difference in brightness between stars of magnitude 1 and magnitude 6 is 100 times. But this hierarchy has also continued, regardless of the distance of the star, which is the brightness of the star when we look at it on Earth. ”

It dawned on Etienne that this was the first time he had heard of the concept of hierarchy: "Is there a star brighter than the North Star?" ”

"Of course, the division of six grades is very rough, and later scientists formulated more grades, if a star is brighter than the Cowherd, then its magnitude is 0, and Vega is a 0th magnitude."

Bi Fang opened the topic for a moment, with the North Star, as long as it is not a dark cloudy sky, it is impossible to lose its way at night, and you can open it boldly with confidence.

"In addition to the North Star, in the dark canopy, we can also use the constellation Orion to orient us. The constellation Orion is surrounded by 4 bright stars forming a large quadrilateral, and in the center of the quadrilateral are 3 small stars side by side. We can make an imaginary horizontal line through the small star, which is the celestial equator, and the line is the east-west line. ”

"Of course, if it's the Southern Hemisphere, it's different, the Big Dipper may be hidden below the horizon, I'll tell you when I get to the Southern Hemisphere."

[Southern Hemisphere?] What's there? 】

[Antarctica, or Australia]

[Why are you still hiding? I'm not convinced! 】

"Ahem, it's all over, what will I talk about in the future." "But it's not enough to have a direction, our route is planned, we are going to Denmark, and it's not good to fly to the Netherlands or Copenhagen, so we not only have to use the stars to judge the direction, but also use it to measure latitude and longitude!" ”

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