Chapter 790 Arrive at Nemo Point

The stars are shining brightly, even the whimpering of the wind can’t hide the brilliance of the stars, shining in the dark night, guiding all lost travelers.

Following the direction of Bi Fang’s finger, everyone was fascinated.

Someone once took a time-lapse photo of the starry sky in the northern hemisphere, and the stars moved. Because of the rotation of the earth, the trajectories of the stars in the sky formed one concentric circle after another.

Only the star at the center of the circle is eternal in the field of vision because it lies on the extension of the Earth’s axis.

This star is called Polaris, and it’s everyone’s old friend.

To observers in the northern hemisphere, the North Star remains stationary, and other stars revolve around it.

and many more……

Northern Hemisphere observers?

Some viewers slapped their mouths, wondering what was wrong.

After a long while, someone suddenly realized that Fang Shen was not in the southern hemisphere?

[Can the Polaris also be seen in the Southern Hemisphere? 】

[I slowly type a question mark]

[Fuck, I just turned the corner, isn’t Lao Fang in the southern hemisphere, how can he see the North Star? 】

“When did I say this is the North Star?” Bi Fang laughed twice, “I never said this was the North Star.”

“I just use Polaris as an example, because the underlying logic is the same, and Polaris is familiar to everyone. I think it may be easier for everyone to understand.”

【I am silly】

【Fake a shot】

【biubiubiu】

[I’m sorry, I don’t understand what star you take. 】

[So what star is this? 】

[So the southern hemisphere is a South Pole star? 】

“There is no so-called South Pole star, this star is actually the central point of the Southern Cross,”

“The North Star is located on the extension of the Earth’s axis, and is very, very far away from the Earth, so far that the radius of the Earth is negligible compared to it.”

“So, looking at the direction of Polaris at a certain position on the earth’s surface, this line of sight is parallel to the Earth’s axis. Then, the angle between this line of sight and the horizon, that is, the elevation angle of Polaris in the field of view, is equal to the latitude of that location.”

“That is to say, if you look for the North Star in the field of vision and find it is directly above your head, that is, the elevation angle is 90 degrees, it means that your latitude is 90 degrees, and you are stepping on the North Pole.”

“If you look for the North Star in your field of view and find it is at the horizon and the elevation angle is 0, it means that your latitude is 0 degrees, and you are sailing on the equator. If the elevation angle is 30 degrees, it means that your current position is 30 degrees north latitude. ”

[I mentioned this last time, I remember that I can use a sextant]

【Fangshen sextant is ready】

[That was the sextant just now, right? 】

The audience remembered the strange thing that Bi Fang took out before he began to calculate, and immediately understood its purpose.

Bi Fang did not deny it.

Luckily, these simple gadgets weren’t lost on previous adventures.

“This is the process of determining the northern latitude, and although the southern latitude does not have a corresponding South Pole star, we found that the center point of the Southern Cross constellation can approximate the role of the South Pole star.”

“Although such observations are not precise enough, they are sufficient for nautical positioning.”

Bi Fang pointed to the starlight in the night sky. After careful observation, everyone found that this star is indeed quite different from the North Star. Although it is also very bright, there is a lot of brightness around it.

Due to the existence of the Polaris and the Southern Cross, experienced navigators can easily determine their latitude with the help of suitable measuring instruments, but the measurement of longitude is much more difficult.

“Latitude is a series of parallel lines, while longitude is a series of lines that meet at the poles.”

“The earth rotates in the east-west direction, and there is no east pole or west pole, so there is no east pole or west pole.”

“However, the navigators still discovered a law, which has nothing to do with the stars, but time.”

“We clearly know the concept of time zones. For example, it is 2:00 a.m. China time and 1:00 a.m. Eastern time. If I know, the current China time is 2:00 a.m., and the current local time is 1:00 noon. So, can I reverse it, and my current time zone is the Eastern Time Zone?”

“Then, I can know that my longitude is the longitude of the east of the Chou Kingdom. Therefore, the measurement of longitude is transformed into the measurement of the time of the known position and the time of the current position.”

[No, my head hurts]

[Master Fang, don’t read it anymore, don’t read it again]

[Dream back to high school geography class]

【Learning is abolished and learning is abolished】

Bi Fang followed up with a series of analyses. The charcoal kept on writing, as if he was explaining and sorting out his thoughts.

“The Earth’s rotation period is 24 hours, that is, it rotates 360 degrees in 24 hours, 15 degrees per hour, and 1 degree every 4 minutes.”

“If the port of departure is used as a reference point, such as from London, the standard time is Greenwich Mean Time, and the longitude where Greenwich is located is the 0 degree longitude.”

“Then at a certain position during the voyage, Greenwich time is 1:00 am, local time is 9:00 am, the difference is 8 hours, that is, the difference between this position and Greenwich is 8 times 15 equals 120 degrees , that is, the current position is 120 degrees east longitude.”

“It’s just that there is a crucial question here. In the vast sea, how to determine Greenwich time and local time?”

【Corona Bar】

【Clocks? 】

“It’s a sundial.”

The crew would keep a sundial on deck and use the direction of the sun’s shadow to determine the time.

The ups and downs of the ship have a great influence on the length of the shadow, but have little change in the direction of inclination.

Greenwich time is determined by clocks. On departure from London, set the clock to GMT and never set it again after that.

[It sounds like it’s a little simpler than the old calculation last time? 】

[I don’t know, anyway, I don’t know any of them, just listen and it’s over]

[I picked up a pen in class, and I never understood Fangshen’s problem-solving ideas again]

Bi Fang shook his head again.

“It sounds simple, but it is more difficult to actually implement. Because this method relies heavily on a precise and reliable clock, otherwise, the effect will be greatly reduced. Although the ancient Greeks invented the theory of longitude, it was limited by the The craftsmanship of clocks, until the 18th century, allowed navigators to accurately measure their own longitude.”

“Before this, there was even a law in maritime navigation where soldiers would be executed immediately if they told the captain about the route at will.

Because they couldn’t determine their own route at that time, it completely depended on the captain’s experience and intuition. They only knew their latitude and not longitude until later reliable clocks were invented. ”

[Hi, it’s all about Meng, right?]

[Actually, you don’t have to know your own latitude and longitude accurately when sailing. This is because Lao Fang has special needs. People at that time, as long as the direction is right, it’s right to bury their heads and move forward. There are also surfaces along the way, such as islands and so on.]

[Indeed, Nemo didn’t order any surface, this is the most annoying mentality]

“For this reason, the method commonly used for a period of time is the lunar distance method, which calculates the world time by measuring the angular distance between the moon and the stars. In addition, there are the Davis quadrant, the starboard and the sextant, which are all The way to resolve your own position at that time.”

“It’s also why many famous watches today have the origin of nautical models. Due to the inconvenience of longitude measurement, navigators have come up with an approximate measurement method, which is to look at distance, which is the so-called nautical mile…”

“Many people may wonder why the distance of sailing is not used in kilometers and miles, such a common unit, but to use nautical miles, as if it is specially designed to make things difficult for others, and the sailing speed must also be used in knots. In fact, this is for the convenience of determining the position, because An arc length of 1 nautical mile corresponds to 1 minute of the central angle of the Earth.”

[Hey, is that so? 】

[When I did similar math problems before, I felt that the sea is very anti-human. Why is it necessary to create a unit of distance and speed when sailing? Is that the reason?]

[Increased knowledge. 】

“Every 1 nautical mile in the north-south direction means the latitude changes by 1 point; every 1 nautical mile in the east-west direction on the equator means the longitude changes by 1 point; if you sail east-west on the non-equator, you need to multiply the reciprocal of the latitude cos as a correction. coefficient.”

“The unit of speed “knot” also comes from this, 1 knot is equal to 1 nautical mile per hour. ”

“So, we just need to know how far we’ve sailed…”

Bi Fang explained carefully, and the movements of his hands did not stop. The black charcoal pen rubbed on the wooden board, leaving dark charcoal ashes.

The torches on the bow swayed in the wind, and the figures flickered.

Of course, the distance calculation cannot be accurate. In fact, the positioning accuracy of the sailing era can be dozens or hundreds of kilometers.

In addition, several methods are mixed, compared with each other, and corrected. Although it is not better than GPS, it is enough for Bi Fang to arrive at the destination accurately.

Although Point Nemo is a point, it does not mean that Bi Fang has to navigate this point accurately to be considered a successful crossing.

Only in its vicinity, this mission can already be counted as a success.

It doesn’t even matter where you go next, whether you go back or keep moving forward to the next island.

Through various calculations and steps, the wooden board seemed to have solved a major math problem, and even a small serial number was marked.

Each serial number represents that Bi Fang used a calculation method to find the location.

When all three coordinates appeared, Bi Fang listed them, then verified each other, and finally let out a sigh of relief.

He shook the wooden board in his hand in front of everyone, circled a coordinate, then dropped the charcoal and lay down in the Viking, looking up at the night sky, his tone was extremely disappointed.

“Luck finally got better last time.”

“Point Nemo, right at our feet.”

Nemo Points… Right at Your Foot! ?

The audience was stunned.

Here it is, is it there?

Everyone who originally thought that there was at least a long way to go, never imagined that the task was actually completed like this?

Bi Fang put his arms under his head, and his heart was indescribably relaxed, and the world widened in an instant.

At the moment when the latitude and longitude came out, on the blue fluorescent system panel, the task finally changed, and the half-completed state was displayed above the Nemo point.

That is, when the body and mind were completely relaxed, Bi Fang’s eyelids suddenly became extremely heavy, and he couldn’t open his eyes for a while.

The audience in the live broadcast room undoubtedly fell into cheers again, and the barrage appeared rapidly, swiping the entire screen, and could not see the actual picture for a while, but soon, some audiences heard some in the wind. other voices.

When the heat subsided a little, and finally could see clearly in the picture, countless people were dumbfounded.

Bi Fang actually fell asleep like this.

……

Not to mention how lively the Internet is, these are all part of Bi Fang’s routine operations. When he wakes up the next day, Bi Fang feels that his energy is unprecedentedly full, and even the soreness in his muscles seems to have eased a lot at once. .

It is only the seventeenth day since Bi Fang set off from Easter Island, and the speed can be said to be extremely fast.

Bi Fang did not let his guard down. Although the most critical part of the mission has been completed, there is still a typhoon chasing behind him. Now is not the time to stop.

During the period, typhoon Harold also made a strong landfall in Vanuatu as predicted, causing extremely serious disasters.

Although there are several relatively powerful storms in the active tropical cyclone season in the South Pacific every summer, it is relatively rare for a strong storm to strike a country with the strongest attitude this year, which may indicate that the climate pattern in the Pacific is in in an abnormal state.

Therefore, for the sake of safety, Bi Fang did not choose to go back the same way, as it might be too dangerous to approach the typhoon, so he chose to move on.

Of the three islands closest to Point Nemo, Ducy and Easter are very close, while Mahe is too close to the South Pole.

“The Star Wants To Retire”

Going to the South Pole, although the typhoon is far away, the temperature will continue to drop. Bi Fang did not bring enough cold clothing.

Therefore, after careful consideration, Bi Fang chose to move directly to South America, which is farther away but more convenient.

During the period, there were not too many accidents. On the thirty-first day, fish in the ocean finally appeared more or less, which alleviated Bi Fang’s food crisis at that time.

On the thirty-fourth day, the first island appeared in front of Bi Fang’s eyes, symbolizing the perfect ending of the crossing.

Looking at the island in front of him, Bi Fang put down everything, no longer paddling, no longer controlling the sail, and his heart was filled with pride.

Bi Fang has truly achieved unprecedented!

The opening remark is no longer an empty word, but everything he has experienced!

“Generations of human beings, that’s it, got into canoes, with hooks and lines, with bananas, cassava, coconuts, and other fruits, with their chickens, pigs, and dogs, with obsidian Tools, say goodbye to the homeland and head towards the vast sea without hesitation.”

“Every time a new island is discovered, it will temporarily stop and develop, and when the time is right, use it as a base to embark on a new journey.”

“We don’t know how many people were devoured by the raging waves, how many people didn’t get to the other side after exhausting the last of food and water, how many people were killed by vicious sharks… but one thing is for sure , mankind has not yielded, mankind has not stopped.”

“This is the story of us, the human race. Nowhere should we forget that we are fragile and small, but we are strong and great.”

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