Reborn Action Star: Starting in Hollywood

Chapter 629 Solving Communication Problems
In the next half day, Lin Yuan, director Cohen, Meng Tao and others on the Virginia were urgently revising the shooting plan.

This step must be done quickly because after the shooting plan is completed, the shooting boat on the water must be notified to make corresponding adjustments and shooting preparations.

At the same time, the Virginia was heading towards the designated filming location along route N-17.

The huge group of bowhead whales and narwhals were leisurely following the Virginia not far behind.

During this period, Lin Yuan would go out of the cabin from time to time to communicate with these temporary animal friends and enhance his ability to adapt to the ice sea environment.

Before we knew it, the preparations for the shooting had gradually matured and we were about to enter the shooting stage.

At this time, in the dining room of the Virginia.

"Lin Yuan, we are ready for filming here. I wonder if the filming ship has arrived?" Depp asked.

Before Lin Yuan could answer, Meng Tao rolled his eyes and replied, "They've already arrived. The research vessel's surface route is straighter than ours. They're already on the surface, waiting for us to give the command to shoot."

"How did the surface filming ship get here? Isn't it said that Greenland's ice sheet is very thick? I heard that the average thickness of Greenland's ice sheet reaches 1400 meters!" Depp asked.

Meng Tao stared at Depp as if he was a moron, which made Depp feel uneasy.

"It's said that you Americans don't study math, physics, and chemistry, and lack basic scientific knowledge. It seems that it's true," said Meng Tao.

"That's right, we don't study brain-intensive math, physics, and chemistry, but that doesn't mean you can insult our intelligence. How can I not have common sense?" Depp protested.

"You don't think Greenland is a big iceberg floating on the water, do you?" Meng Tao asked.

"Isn't it? I looked at all the maps and pictures, and Greenland is just a big ice sheet." Depp said confidently.

Meng Tao slapped his forehead helplessly: "Have you heard of the tip of the iceberg?"

"Well, what's wrong?" Depp asked.

"If Greenland is really a large ice sheet floating on the water, with an average thickness of 1400 meters and a maximum thickness of 2700 meters, then doesn't that mean there are at least 1000 meters of ice underwater? This means that if you sail more than meters underwater, you may hit the bottom of the ice sheet. Do you think this makes sense?" Meng Tao asked.

Depp: “…”

The brainless Depp finally realized that something was wrong. Most submarines cannot operate in waters deeper than 500 meters because the huge water pressure will crush the submarine's hull.

If there really were ice 1000 meters underwater, wouldn't there be ice everywhere in the Greenland waters?
Meng Tao sighed and said, "Greenland is a landmass like Antarctica, with its crust protruding high above the seabed. However, this landmass is covered in ice and snow. Does this give you the misconception that Greenland is a giant block of ice floating on the sea?"

Hearing Meng Tao's answer, Depp's face turned red with shame.

The so-called happy education in the United States in recent years has made them lose even the most basic scientific knowledge, and even anti-intellectualism is prevalent.

In school, smart and excellent students are often belittled as nerds, while those simple-minded but strong-limbed football players are the most respected and popular types among girls.

Depp vaguely felt that it was wrong to do this. With only a strong body but an empty mind, could he really support this society?
In Depp's own opinion, he is considered a smart person among his childhood friends. But people like him alone cannot support this country.

Depp asked, "So where are we? The ice cap above us?"

Meng Tao said: "We are now in the waters northwest of Greenland, and we are heading north along Baffin Bay.

坐标大约是北纬86度41分，西经64度21分，头顶上漂浮的冰盖层平均厚度在5米左右。”

Worried that Depp still didn't understand, Meng Tao added, "Even in the Arctic Circle, 5 meters of ice is the thickest. This caused considerable interference with our communication with the surface, and the subsequent filming process would not be smooth.

Communications is the biggest problem. Even though the filming ship overhead is a military vessel dispatched by the Atlantic Fleet, it still presents significant challenges."

"Communication problems?" Depp asked puzzledly, "Is it difficult for submarines to communicate with the surface?"

Meng Tao sighed and said, "Let Lin Yuan explain. He has a better temper than me and is more patient. I can hardly hold back my fists any longer."

Hearing about the communication issue, Director Cohen immediately asked, "Is communication difficult? Then how will we communicate with those on the surface to coordinate the filming?"

We can't be performing enthusiastically underwater while the filming boat on the surface doesn't cooperate at all. Wouldn't that be a waste of effort?"

After learning about this situation, Director Cohen was obviously a little anxious.

Fortunately, Lin Yuan and Meng Tao had already made relevant preparations. Meng Tao nodded to Lin Yuan, indicating that Lin Yuan should answer the question.

If it was just a simple scientific introduction, Lin Yuan might not want to waste time talking about it.

But this matter does involve the subsequent filming work, and even in case the submarine encounters an accident and wants to save itself, external communication is of paramount importance.

It is indeed necessary to let directors Depp and Cohen, who are not very familiar with the matter, understand it clearly.

Lin Yuan smiled and said, "Our long-distance wireless communication method mainly relies on electromagnetic waves. Do you have this basic concept?"

Director Cohen and Depp nodded, he still understood electromagnetic waves.

Lin Yuan continued, "The transmission capability of electromagnetic waves in water is very weak. Very weak."

"How weak?" Depp asked.

"50."

"50 meters?"

"50 centimeters."

"..."

50cm?

It’s so off the mark!

A distance of 50 centimeters is not even as long as a leg?
What can be done at this distance?
Directors Depp and Cohen were completely speechless.

Lin Yuan said: "There is no way. The commonly used frequency band of communication electromagnetic waves can't even reach 50 centimeters underwater, so it has always been difficult for submarines to communicate with the outside world."

"Why?" Depp asked immediately.

In his understanding, electromagnetic waves can easily cross thousands or tens of thousands of kilometers, so why can't they cross a distance of just 1 meter underwater?
"When water contains impurities, it is a conductor. Therefore, it has a strong attenuation effect on electromagnetic waves, especially seawater with extremely high salt content, whose conductivity is much higher than that of ordinary pure water." Lin Yuan explained.

"Yuan Shen, you really are much more patient than Meng Tao! You explained this principle in a simple and easy-to-understand way. Even someone like me who hasn't studied much science can understand it. If Meng Tao had explained it, I would definitely be confused." Depp didn't forget to complain about Meng Tao. The two of them are indeed good friends.

Director Cohen nodded in understanding, but he also raised a concern: "Since underwater transmission of electromagnetic waves is so difficult, what is the solution?"

"Long wave communication." Lin Yuan said.

"Long wave communication?" Depp once again exposed his ignorance.

"The longer the wavelength of a radio wave, that is, the lower the frequency, the less it attenuates in water," Lin Yuan said. "So, based on this principle, each major military power has built its own long-wave radio station."

When saying this, Lin Yuan recalled the breakup between the Eastern superpower and its big brother. One of the factors was that the big brother proposed to build a long-wave radio station.

This type of military equipment, which is of great value to global naval deployment, especially the communication and command chain of strategic nuclear submarines, has a huge impact.

"That's great. With long-wave communication, we can communicate smoothly with the surface filming ship?" This is what Director Cohen has always been most concerned about.

Lin Yuan shook his head: "Unfortunately, long-wave communication also has two major shortcomings."

"The first point is that the information that can be sent is quite limited," said Lin Yuan.

"How limited?" Director Cohen asked.

Lin Yuan patiently explained, "The world's most important long-wave radio stations use a frequency band called 'Very Low Frequency'. The frequency band commonly used in the military is around 2000 Hz, and they use the MSK minimum frequency shift monitoring method to transmit."

Director Cohen: “…”

Depp: “…”

The two said they didn't understand, and Lin Yuan didn't want to explain, so he said it in a different way:
"The bandwidth is around 300bps."

Director Cohen: “…”

Depp: “…”

So Lin Yuan continued to change his expression: "37.5 bytes per second."

Director Cohen: “…”

Depp: “…”

Lin Yuan expressed his helplessness. How bad is the basic education in the United States? Isn’t it a country with strong Internet technology?
Now it is the Internet age, you must be online a lot, right?
Don’t you even understand what 37.5 bytes per second means?

He hasn't explained yet that the 37.5 bytes transmitted are just plain text.

In fact, very low frequency communication is a broadcast communication method. All the information sent can be received not only by our side but also by the enemy.

Therefore, the information must be encrypted. In addition, the recipient, file header, verification information, etc. occupy communication bytes, and the effective information that can be transmitted is further compressed.

I really don't understand what Director Coen and Depp are saying.

Lin Yuan could only continue to lower the difficulty: "The actual communication efficiency is only about one text message per minute."

This was before the mobile internet era, with no social media apps like Facebook, WeChat, or Twitter. Besides making phone calls, people primarily used text messaging. When Lin Yuan used text messaging as an example, Cohen and Depp immediately understood.

Just one text message per minute?
Isn’t this communication efficiency too low?
This made Director Cohen feel worried.

But he still continued to listen to Lin Yuan, because the disadvantages of long-wave communication are not just the low communication efficiency, there is another point that Lin Yuan did not mention.

"The second disadvantage is that the wavelength of long-wave communication is very long, so if you want to transmit long-wave radio, the antenna size will be very large," said Lin Yuan.

"How big is it?" Director Cohen asked immediately.

Lin Yuan said, "You may not have seen what a long-wave radio station looks like, so let me describe it to you. Each long-wave radio station consists of a core signal transmission tower about 400 meters high, supported by 12 shorter transmission towers around it.

These towers are arranged in a hexagonal pattern, connected by antennas. When viewed from above, they resemble the ribs of an umbrella, hence the name "umbrella antenna."

The span of a set of umbrella-shaped antennas can reach 2000 meters.

When such a large long-wave radio station is operating, the transmission power can reach between 1 and 2 million watts."

Lin Yuan was worried that Director Cohen and Johnny Depp might not understand what this power meant, so he added, "The walkie-talkies we use in our daily lives have a power of about 0.5 watts."

For director Cohen, the walkie-talkie is a very familiar device.

Which studio, which director doesn’t use it when shooting a movie?
If we say that on the set, the walkie-talkie that can communicate smoothly within a range of tens or even hundreds of meters only has a transmission power of 0.5 watts.

Then a 200 million watt long wave radio station is simply terrifying!
But Lin Yuan's next words dispelled all the expectations of Director Cohen and Meng Tao:
"Even a long-wave radio station with such a large area and such powerful power can only transmit long-wave signals to a submarine 1 kilometers away through a depth of about 20 meters."

Director Cohen: “…”

Depp: “…”

Hearing this, Director Cohen was completely desperate.

He had vaguely known before that submarine communications were difficult, but he had never imagined it would be so difficult!
First of all, the amount of information communicated is extremely limited, with only one text message per minute.

Secondly, the huge size of the long-wave radio station means it is impossible to fit it into a submarine. There is absolutely no submarine in the world that can fit an antenna array that is 400 meters high and 2000 meters wide.

This makes long-wave communications only one-way, meaning that the land command post can issue commands to the submarine, but the submarine cannot respond to the commands.

The last point is that even after incurring the two huge costs mentioned above, long-wave communication can still only reach a depth of about 20 meters underwater.

Even if the distance is closer, the depth will not exceed 30 meters.

The shooting depth of the Virginia this time was 200 meters underwater!
In this way, the model sent from the surface cannot be transmitted at all, and even one-way communication is impossible.

Now Director Cohen finally understands why many submarines are unable to send out distress signals after accidents.

Even the naval command did not know where the submarine was located or when the accident happened.

Only after missing several agreed communication time points in a row did they realize that something might have happened to the submarine and immediately organized rescue and search operations.

I have to say, submarines are really difficult.

No wonder submarine officers and soldiers feel depressed, because once something happens, it will be difficult to get rescued, and they will most likely die in the desperate waiting.

The biggest advantage of submarines is their underwater stealth, but this stealth is obviously a double-edged sword, and it also brings huge risks and psychological pressure to submarine officers and soldiers.

Director Cohen and Depp immediately felt a chill in their hearts when they thought that they were in a submarine.

"Since you know so many disadvantages and still dare to insist on implementing this shooting plan, you must have a solution, right?" asked Director Cohen.

"The combination of extremely low frequency and long wave communication floats." Lin Yuan said.

"Combination of extremely low frequency and long wave communication floats?" *2
Director Cohen: (1`1;)
Depp: (▔皿▔)
Although neither of them understood, Director Cohen was obviously excited after hearing that there was a solution.

Depp was confused and had a splitting headache.

Damn the world of science! Why does something like this exist that is completely incomprehensible to people?
Lin Yuan continued to explain: "The so-called extremely low frequency is an ultra-long wave with a frequency band of around 80HZ."

Now even Depp understood. Lin Yuan had just said that the only way to increase the transmission distance of radio electromagnetic waves underwater is to lower the frequency and increase the wavelength.

Although the underwater transmission distance of 2000HZ very low frequency is longer than 50cm, 20 meters is still not enough.

Therefore, if the frequency is further reduced to 80HZ, the underwater penetration distance will inevitably be greatly improved.

"But using extremely low frequencies will lead to a further reduction in bandwidth and a further increase in the size of the transmitting antenna, right?" Depp raised his hand and asked.

His expression was full of pride, and he was pleased with his own cleverness.

Lin Yuan has just explained in detail that the higher the frequency of the radio signal, the greater the amount of information it can carry.

The frequency of extremely low frequency is significantly lower than that of very low frequency, so the amount of information it carries is probably terribly low.

Another point, as Lin Yuan also said, is that if you want to transmit long-wave signals, you need a very large antenna.

An umbrella-shaped antenna occupies an area of ​​more than 2 kilometers, so the area occupied by an extremely low frequency radio station is even more unimaginable.

Before Lin Yuan could respond to Depp's temperature, Meng Tao said in astonishment, "Great, Depp! I didn't expect you to be so smart. Who says you Americans can't learn science? It seems your country simply hasn't created the conditions for you."

Meng Tao accidentally discovered the truth of the matter.

The so-called happy education in the United States is essentially the country’s unwillingness to invest a lot of resources in education to cultivate its own talents.

After all, science education requires a large number of instruments and equipment, as well as more professional teachers than liberal arts education, and the cost of education is obviously higher.

How can we save more education funds than letting students learn literature and art through joyful education?
What about the needed science and engineering talents?
Haha, wouldn’t it be better to issue green cards to the two Eastern giants and those risk-prone countries in East Asia?
How many graduates from the top two universities in the East have come to the United States? They can even hold class reunions in Silicon Valley.

Please note, it is a class reunion, not a school reunion!
By directly harvesting science and engineering talents trained in other countries, the United States not only does not need to bear the cost of talent training, but can also poach talents from its opponents and weaken the possibility of its opponents' rise.

It’s like winning twice, it’s so exciting!
It has to be said that countries where capital is paramount always put profits and input-output ratio first.

As for those abandoned lower-class people, who cares?
If they complain in the future that they have no jobs and their positions have been taken away, we can still put a hat on them:
Who made you lazy and afraid of difficulties and not learning science and engineering knowledge?
What makes you think that you only know how to play ball, date, and admire sports stars?
It’s not that we don’t give you good job opportunities, but are you capable of doing these technical positions?

Obviously, Americans are not really unsuitable for studying science and engineering, otherwise they would not have led the way in technological progress in the past.

It’s just that capital, based on its own interests, has given up the route of cultivating talents in its own country at a huge cost.

Although Depp is a bit clueless, he is actually really mentally retarded. With proper education, he can become a fool!

This is what Meng Tao thought.

Lin Yuan said in an encouraging tone, "Depp, you are absolutely right. I didn't expect you to be able to draw inferences so easily."

Hearing Lin Yuan's praise, Depp straightened his back with a proud expression on his face.

Lin Yuan said: "In Wisconsin, located in the heart of North America, there is an ultra-large extremely low frequency signal transmission array spanning 200 kilometers. It can achieve global communication and send commands to submarines underwater anywhere in the world."

"How much?" Depp asked in surprise.

200 kilometers?

"Our country has the ability to build such a large project? How come I didn't know?" Depp asked.

In his impression, his country is a poor engineering expert. It took ten years to build a highway, and it cost billions of dollars but still ended in failure.

Are they actually capable of building a huge signal transmission array spanning 200 kilometers?
"This ability existed 20 or 30 years ago, but it's gone now." Lin Yuan didn't delve into the issue, but continued:

"The problem you mentioned about low bandwidth does exist. Even with the best encoding, the communication efficiency is less than 1bps using extremely low frequency communication."

Lin Yuan had already figured out that Director Cohen and Depp didn't understand, so he explained further, "That means about three letters can be sent every 15 minutes."

Director Cohen: “…”

Depp: “…”

Director Cohen and Depp have expressed their speechlessness countless times today.

Lin Yuan smiled and said, "Don't underestimate the three letters sent every 15 minutes. They can already send a command according to the pre-agreed code book, for example, Z represents a communication command.

When the Virginia receives the communication command underwater, it can immediately release a long-wave communicator with a float.

The float will carry this wired long-wave communicator and float to a depth of about 20 meters, where it can receive very low frequency long-wave communication signals.

After hearing Lin Yuan's explanation, Director Cohen and Depp finally understood.

It has to be said that faced with the communication difficulties of deep-sea diving, engineers made countless difficult attempts and finally found a solution.

This way of solving the problem, full of scientific beauty, gave Director Cohen and Depp a strange shock:

It turns out that science and engineering knowledge is not so boring. On the contrary, it can be very interesting and even make people feel a sense of accomplishment.

At this moment, a thought flashed through their minds:

its not right!
Lin Yuan, you are a Chinese who grew up in the American education system. Why do you understand all this?
Tell me quickly, are you cheating secretly?

(End of this chapter)