Technological power starts with upgrading lenses

After going through a series of certification procedures, Kang Chi finally returned to his laboratory. Seeing the familiar scene that was cleaned and tidy by Bai Niu, Kang Chi couldn't help but let out a deep breath.

In the past few days, the engine has been tested, the plane has been flown with great joy, and I have even experienced supersonic flight. Next, I will finally start new research.

It is also a very challenging project.

He walked to his desk and sat down, looking at the various materials and drafts on the table. They were still in the same position as when he left.

Although Fat Girl can clean and organize the laboratory, the three meters around this desk are her restricted area.

Picking up the top draft, I looked at the few lines I wrote on it when I took some time out some time ago:

No matter how far apart the two spins are, as long as a·b≠0 (not orthogonal), their projection measurement results on a and b are related. Both sides measure the spin in the z (or x) direction, Q(z, z)=-1=Q(x, x), when the two directions of measurement are perpendicular, the correlation function is 0...

After briefly thinking and recalling it, Kang Chi began to write down, and he continued writing all morning.

In fact, when developing the turbofan 30, Kangchi took the time to read all the information related to communication technology that he could find, and determined a general research direction.

He and Ren Zhou actually had similar ideas. Electromagnetic wave communication was definitely not safe enough. He had to find a new forest. For now, Kang Chi believed that the most likely solution was actually quantum technology in the true sense. communication.

When it comes to quantum communication in the true sense, we have to mention pseudo-quantum communication, which has now entered the stage of practical application.

In fact, the current quantum communication can only be said to be quantum secure communication. China is currently in an international leading position in this technology.

As early as 2022, Professor Long's team at Peking University achieved direct quantum communication over a distance of 100 kilometers, which was more than five times longer than the second place.

There are many traditional communication methods. For example, if a handsome man wants to express his love to a goddess, he can directly write a letter and hand it to the goddess in person, or he can call her on his mobile phone to tell her, or he can also send her an email.

But Xiaoshuai was shy. He was afraid that others would know about his confession, so he gave the goddess a code book in advance, and then sent a string of Morse codes to the goddess. After comparing the codebook, the goddess immediately understood that Xiaoshuai liked him. Own.

This method can already prevent most people who peek at the screen from knowing what Xiaoshuai conveyed, but this is not safe enough, so it can continue to upgrade the codebook, such as using the prime common factors of a large series of numbers as the agreed password to crack The difficulty immediately went up a level.

However, with the improvement of the computing power of modern computers and the emergence of quantum computers, this password has become unsafe, and Xiaoshuai's confession may still be deciphered by roommates who peek at the screen.

So when we are indecisive, quantum mechanics, at this time quantum entanglement can come in handy.

For example, traditional communication uses radio waves or visible light wavelengths to transmit data of 0s and 1s. If someone else finds your transmission frequency, it is easy to get a series of the same data and then decrypt it.

But quantum encryption, although it also uses radio waves to emit waves (photons, quanta, almost all particles are essentially waves), can make each wave contain data, and each wave is between 0 and 1. In an uncertain state, only the two parties in communication can correctly interpret the information inside by using the agreed upon observation and decryption method.

If the thief wants to obtain the data, he has to steal the sending wave for observation. Not only will the two parties immediately discover that someone has stolen the data, but also due to the uncertainty of quantum, the data obtained by the thief will also be garbled and have no value. .

This uncertainty in data is the principle of quantum entanglement.

Quantum entanglement refers to two entangled quanta A and B. No matter how far apart they are, they can produce a linkage.

Before observation, the spin directions of the two quanta are random, in a superposition state of upward spin and downward spin. However, if quantum A is observed, it will collapse instantly and become fixed downward or downward. Fixed up spin.

And if the spin direction of quantum A is observed to be upward, the spin direction of quantum B will also collapse to downward at the same time.

Therefore, many people believe that super-light communication technology can be achieved by using the principle of quantum entanglement.

But in fact, the randomness of the quantum spin direction ends at the moment it is observed, and it has collapsed to an eigenstate. After that, the same observation is made again, and the result is the same.

It's a bit like playing a one-two-three wooden man, and the observer also has the petrification effect of Medusa, which turns the man into a statue after just one play...

For example, two people, A and B, each take a quantum in an entangled state, and then A takes a spaceship to search for alien life. At the same time, they agree that if the spin is downward, the alien has been found, and if the spin is upward, the alien has not been found.

But because the direction of quantum spin is truly random, A cannot control whether the quantum spin is up or down at all, so the message transmitted through observation is invalid.

Even if the number of entangled quanta carried by each other is increased, the result will be the same. Even if it collapses after looking at it once, both parties don't even know who measured it first or who wanted to send information to whom.

Therefore, although it is possible to transmit information at super-light speed through two entangled quanta, it is all invalid information. This is like a chain of suspicion, falling into an endless loop.

What Kang Chi has to do now is to find the theoretical loopholes in this endless loop.

This process is quite grueling.

As time went by, some of the pieces of scratch paper filled with calculations were thrown to the ground, while others were pasted on the whiteboard.

In the past, physics was all about observing phenomena through experiments and drawing conclusions. However, when the laws of the macroscopic world were roughly summarized, and after entering the microscopic world, it gradually turned into conjectures and looking for phenomena to be confirmed.

To put it bluntly, guessing is just opening up your imagination.

Some people may say, who can’t use their imagination?

It turns out it’s so easy to become a scientist!

In fact, it really is that easy.

If you can come up with a conjecture that no one has ever proposed before, and it is eventually proven to be correct.

Congratulations, you can proudly call yourself a scientist and your name will go down in history!

But the problem is that with the development of science and technology at this stage, it is actually very difficult to come up with a conjecture that has never been proposed before, because most of the imaginative conjectures are easily proven to be wrong in the end, and those What is proven to be correct has become the truth.

The remaining ones, which no one can prove are right or wrong, have become world problems. Solving any one of them can cause a sensation in the international academic community.

The cost of thought experiments is also very low. High-energy physics requires tens of billions to build a particle collider, but studying quantum mechanics may only require five steamed buns a day!

On the contrary, Kang Chi hoped that this thing could be solved by spending money to build something.

But the problem is that theoretical research is so metaphysical. If there is no feasible theoretical direction, you don’t even know what to build.

It's just like when you want to go out. If you don't even have a destination and direction, how do you know what kind of transportation you need?