With the development of artificial intelligence, virtual reality, etc., the amount of data to be processed is increasing, but the limits of integrated circuits are approaching. So instead of gates made of transistors, quantum computers that use quantum as their operational rules are emerging as an alternative. What exactly is quantum, and what can we do with it as an alternative? A reporter who has no connection with science takes a close look at everything from quantum to quantum computers, which are a recent issue, with a learning heart.

There aren't any black cows here who haven't bought Namhae stocks, right?
In the first half of 1720, a stock market mania swept through England. At the center of the mania was the South Sea Company.

The South Sea Company was originally established to take on the British government's bad debts. In return, it received a monopoly on South American trade, but it was not very profitable because of its virtual enemy, Spain. Most of South America was a Spanish colony. In 1718, the South Sea Company issued bonds in the form of lotteries targeting the middle class, who had investment funds but no place to invest, and these became a huge success. Encouraged, the South Sea Company attempted to transform itself into a financial company, and in 1719, it paid 7.5 million pounds to the British government and, in exchange for acquiring a large amount of bonds, acquired the right to issue South Sea Company stocks equivalent to the face value.

However, the huge 7.5 million pound repayment fee was a problem. The South Sea Company, which was on the verge of collapse due to financial difficulties, decided to sell its own stocks and make a lot of money all at once. The South Sea Company made every effort to raise the price of its own stocks, including by handing out money to politicians. In January 1720, the South Sea Company stocks, which were worth 100 pounds per share, soared to 1,050 pounds on June 24. At that time, the British, like the Koreans the previous winter, bought the South Sea Company stocks without exception. And they all went bankrupt. The British government began regulating the market due to the proliferation of unlicensed companies following the South Sea Company, and the stock prices returned to where they were. The South Sea Bubble ended with the overthrow of the British Prime Minister by angry investors and the introduction of the auditing system.
The famous Isaac Newton said something when he saw this. “The motions of heavenly bodies can be calculated, but the madness of men cannot.” He said this after he invested more because he was glad to have earned 7,000 pounds during the whirlwind, but lost 20,000 pounds. He was just an ant who didn’t even know the stock market.

Who was Newton? Even Gottfried Leibniz, who fought fiercely over who first invented calculus, did not spare his praise, saying, "If we look at the mathematics of the history of mankind up to the time when Newton lived, he has accomplished more than half of it." In this way, Newton's reputation was high and recognized by everyone, but he fell on his butt. Even Newton, who compiled classical mechanics and gave it the nickname Newtonian mechanics, could not explain the physiology of the stock market.

It's not just stocks. It's also quantum mechanics. Newton's classical mechanics cannot explain quantum mechanics. I'm not trying to say that Newton was wrong. Newton's contributions to physics are indescribable, and classical mechanics is still useful in the macroscopic world. It's just not useful in the microscopic world. Humans cannot recognize what they cannot recognize. In Newton's time, atoms were not recognized. And it was not until the 20th century that mankind actually recognized atoms.


Limitations of classical mechanics
In classical mechanics, physical quantities such as energy, momentum, and velocity are considered continuous quantities, unlike substances made of granular matter. When energy is applied to a stationary object, the velocity increases and the kinetic energy also increases. It seems that energy increases very slightly and continuously from 0, but this is not the case. Since energy is also made of chunks, it can only be given and received in chunks, and therefore energy increases only in integer multiples of this chunk.

For example, if the size of a lump of energy is 10, the energy that an object can have is only 10, 20, 30, ... These lumps of energy are called quanta, and energy that is made up of lumps like this is said to be quantized. If energy is quantized, other physical quantities related to energy must also be quantized.

The reason why mankind did not know this fact until the 20th century is because the energy lump is very small. The fact that physical quantities are quantized was completely different from what we had experienced before. Classical mechanics, which can only handle continuous physical quantities, cannot explain this, so a new physics that handles these discrete physical quantities is needed.


The beginning of quantum mechanics, the black body radiation problem
Quantum mechanics was born in the process of solving the black body radiation problem.

The Alsace-Lorraine region is still a representative iron ore producing region in Europe. At the end of the 19th century, Germany, which occupied the Alsace-Lorraine region, developed an iron and steel industry based on the region’s abundant iron ore. At that time, the issue in German industry was to determine the temperature of the molten iron by looking at its color. This was because the process had to be changed depending on the temperature of the molten iron. I knew empirically that blue light is hotter than red light, but I needed a scientific explanation for why that was.

A black body is a hypothetical object that absorbs all light from the outside and does not reflect it. A black body, which is a perfect absorber, does not reflect light, so the light from a black body is only the light that it emits itself. At the time, scientists tried to explain how the color of light emitted by an object changes depending on the temperature of the object through a black body. John Rayleigh, James Jeans, and Wilhelm Wien tried to explain this using classical mechanics, but it was impossible.
The problem of black body radiation was successfully explained by the 'Max Planck law', which introduced the 'quantization hypothesis' by German physicist Max Planck. The content of the law is that the energy of black body radiation must be an integer multiple of the product of a specific constant called Planck's constant and the frequency.
The core of the quantization hypothesis used by Planck is that the energy of electromagnetic waves is quantized. Energy cannot be given and received in arbitrarily small amounts, but can only be given and received in chunks of a certain size. Using the equation, the energy of an electromagnetic wave with a frequency of ν can only be released as a lump of energy called hν, where h is Planck's constant (energy per unit frequency). Planck received the Nobel Prize in Physics in 1918 for this theory.


No, I don't think so
However, Planck was indifferent to the quantization hypothesis, saying that it was just a hypothesis. This is because when Planck explained the black body radiation problem, it was around the time that Mach was attacking Boltzmann in Part 2. In the process of finding a theoretical basis for the new radiation law he had obtained, Planck unexpectedly encountered a situation where he had to accept the atomistic entropy law that Boltzmann's statistical mechanics had assumed.

Planck had not accepted Boltzmann's statistical mechanics when discussing the second law of thermodynamics. However, in the process of finding a systematic explanation for the new radiation equation, he reluctantly accepted Boltzmann's statistical mechanics. For Planck, it was more important to derive a systematic law of nature that satisfied both classical electromagnetism and Boltzmann's statistical mechanics than the quantization hypothesis. Planck was strongly resistant to the idea that light was a particle.
When Planck was young, he decided to study physics and went to see a physics professor at the University of Munich. The professor advised him not to study physics, saying, “Physics is a field that is almost complete, with everything that can be discovered already discovered.” Planck studied physics because he was “satisfied with the mere understanding of what is already known.”

Ironically, Planck became the founder of quantum mechanics through his quantization hypothesis. He tried to explain the quantization hypothesis he proposed within the framework of classical mechanics. However, contrary to his attempt, quantum mechanics went in a completely different direction from classical mechanics.

Some call Planck 'the youngest of classical mechanics and the eldest of quantum mechanics.' However, Planck was not the only physicist who contributed to quantum mechanics but failed to recognize it. Einstein and Schrödinger also showed skeptical reactions to quantum mechanics despite their great contributions to it.

We briefly looked at the beginning of quantum mechanics. In the following article, we will look at how quantum mechanics has grown.