"Yes, it's really troublesome," the expert in mechanics discussed: "Many technological advances are essentially advances in materials science."

"If there is no rare earth, it will be difficult to make progress in materials science, so naturally there will be no powerful engine. Even some composite ceramics require rare earths."

How important are rare earths?

In materials science, it is as important as oil!

Take the engine as an example: In the era of turbojet engines, the gap between the turbine blades and the receiver is wider, the temperature before the turbine is low, and the deformation amount of the turbine blades when working is within a controllable range, and conventional materials can still be used.

In the era of turbofan engines, the front temperature of high-pressure turbines is higher and the blade gap is smaller, so the problem of turbine blade deformation is particularly prominent. The main element to solve this problem is rhenium. Adding rhenium to nickel alloys can significantly increase the creep strength of the alloy and can also resist deformation well under long-term work.

If this element is lacking, then the Tep people will never develop into turbojet engines. No matter how smart they are, they will be hard to cook without rice.

Most of the ones that can be used on mobile phones are light rare earths, and the reserves are quite sloppy, but heavy rare earths like rhenium are very few.

"The resource of exploitable rhenium on Earth is only 2,500 tons, and this planet may be even smaller, maybe only…100 tons? Such a large planet is not useful at all."

Zhang Yuan couldn't help asking: "Our material technology now uses composite ceramics and nanomaterials widely, right? Many materials do not have rhenium. Is there any possibility of refractory?"

"It's impossible. Many materials still have to use rare earth elements. It's because we have developed for hundreds of years... no, thousands of years. Captain, we are already in a third-level civilization." The scientist said: "You have to eat rice one bite at a time, and you have to walk step by step. Without the previous results, it's impossible that there will be funds to study subsequent results."

"If you can't even study ordinary propeller aircraft and jet engines, how can you get our ramjet engine in one step?"

This is also one of the important reasons why the Taipu civilization has not yet created an aerial vehicle. It is not only because of insufficient money, but also because of the lack of materials.

Of course, the Tep civilization also faces the fourth difficulty, that is, the atmosphere is too thick and the rocket launch is difficult.

The friction coefficient of the atmosphere is proportional to the air density. Rockets flying at high speed will be subject to greater resistance. At the same time, the high temperature on the rocket's surface also puts forward more requirements for materials science.

"If this civilization wants to launch rockets, it must have higher performance materials. However, this difficulty is the simplest point, and it can be overcome by barely being able to overcome it."

"The above is the objective environment that Taipu people currently face, all of which are difficult points."

Hearing this, Zhang Yuan frowned, "Compared with humans, the Taipu people are really an unfortunate civilization... So, if I were the leader of the Taipu civilization, it would be a very cost-effective thing to launch some satellites with the help of humans."

Li Zhendong continued: "As for the next few decades, this batch of satellites will be scrapped, it doesn't matter whether there will be a next batch of satellites. Anyway, I am no longer in office, and I am likely to retire, and the people will only read my goodness."

"You are very politically conscious."

So, suppose that the enlightener civilization has really come to this planet 150,000, and after they have inspected the entire planet, they should be able to foresee these difficulties, so how can they help them? In particular, this kind of help may occur hundreds of thousands of years later.

This question is very complicated, and enlightener civilization has always disliked direct gifts.

"If it were humans, it would be really hard to help without giving technology directly. In particular, the other party was a group of primitive people 150,000 years ago... High gravity, high air pressure, and lack of rare earth elements, how to solve it? They can't understand things like rare earths when they talk to primitive people."

The expert said excitedly: "...so we follow the archaeological idea and study what major events happened 150,000 years ago, whether it is natural disasters or man-made disasters. If this matter has enough influence, we will definitely find some clues in history."

"Sure enough!"

"After fifty thousand years ago, a super earthquake broke out from the ocean!"

"Conservatively estimated that the magnitude reached at least 13."

A magnitude 13 earthquake!

Each magnitude difference of magnitude 1.0 is about 32 times the energy difference. That is to say, a magnitude 6 earthquake is equivalent to 32 magnitude 5 earthquakes, while a magnitude 7 earthquake is equivalent to about 1,000 magnitude 5 earthquakes.

Then, a magnitude 13 earthquake is equivalent to 32,000 magnitude 10 earthquakes!

Such a super earthquake can already cause the displacement of crustal plates.

At that moment, a huge tsunami occurred!

A large number of volcanoes erupted at the same time, and the overwhelming dust blocked the global sunshine. Immediately afterwards, due to the sharp drop in temperature, it brought about heavy rainfall around the world. A Little Ice Age, which was produced by an earthquake, was born.

This Little Ice Age did not last too long, and it lasted for about two years. A large amount of precipitation caused the dust in the sky to fall again, revealing bright sunshine.

In 2 years, the species will not be extinct.

However, the Tep people have not yet examined the specific cause of this earthquake, and can only ambiguously attribute it to the movement of the crustal plates.

Zhang Yuan couldn't help asking: "So, is this earthquake related to the enlightener civilization? Could it be that rare earth elements appear in large quantities in volcanic eruptions and earthquakes? This is a little possible...but this method is a bit too rough... did it explode?"

This is the intuitive idea of ​​many people, so that everyone was surprised and speechless.

The scientists on the stage couldn't help but smile bitterly, and then said: "We first examined the earthquake's area, which was already a deep-sea area, and the deepest trench could reach 30,000 meters. I think even if the deep-sea area contains huge mineral resources, the Taipu civilization cannot develop it."

"Even we can't develop the 30,000 seawater."

The ocean is indeed a huge treasure house. Deep-sea manganese nodules are famous deep-sea minerals, containing more than 20 elements such as manganese, iron, nickel, cobalt, etc., and have great economic value. However, these mineral sources will naturally occur even without earthquakes.

Most subsea mineral mining bases are built in shallow sea areas. Deepwater drilling for humans generally refers to the depth of offshore operations exceeding 900 meters, and extreme water depth refers to the depth of water greater than 1,500 meters.

The deeper the water, the greater the difficulty. Even human submarines appear to be a bit difficult in the 30,000-meter deep water area, let alone large-scale development.

"It is not possible to confirm whether the earthquake has an impact on the global submarine mineral quantity. According to computer simulations, after a major earthquake, there is a certain probability that the world's submarine mineral resources will be more... We cannot measure the specific numbers."
Chapter completed!