At the end of 1902, Marie Curie extracted one-tenth of a gram of extremely pure radium chloride and accurately determined its atomic weight. Since then, the existence of radium has been confirmed. Radium is an extremely difficult to obtain natural radioactive substance, its shape is shiny, white crystals like fine salt, radium has a slightly blue fluorescence, and it is this beautiful light blue fluorescence that incorporates a woman's beautiful life and unyielding faith.

In spectral analysis, it is not the same as the spectral lines of any known element. Although radium is not the first radioactive element discovered by humans, it is the most radioactive element. Its powerful radioactivity can be used to further identify many new properties of radiation.

so that many elements can be further applied in practice. Medical studies have found that radium rays have very different effects on different cells and tissues, and those cells that multiply quickly are quickly destroyed by radium irradiation.

This discovery makes radium a powerful tool for the treatment of cancer. Cancerous tumors are made up of cells that multiply abnormally quickly, and radium rays are much more damaging to them than the surrounding healthy tissue. This new treatment soon developed in countries around the world.

In the French Republic, radium is known as Curie.

The discovery of radium has fundamentally changed the basic principles of physics, and is of great significance for promoting the development and application of scientific theories in practice.

Albert Einstein said, "Of all the world's celebrities, Mary? Curie was the only one who wasn't spoiled by fame. ”

Dean of the Academy of Sciences: Mary? We salute you as a great scholar, a great woman who dedicated her work and sacrificed herself for science, a patriot who always worked for her deserved responsibilities, whether in war or in peace. You are here, and we can get spiritual benefits from you, and we thank you; We are proud to have you among us. You are the first French woman to enter the Academy of Sciences, and you deserve it.

The Poles will say that this woman is Polish, and the Warsaw people will say that this woman is my Warsaw.

In addition to Warsaw, Ye Chao also visited the magical underground salt mine - Wieliczka.

This city really has its magic......

"Wieliczka" means huge and great in Polish. The salt mine in this name lives up to its name.

It is like a "city" hidden one or two hundred meters underground, with hundreds of kilometers of winding passages and plank roads, connecting more than 2,000 caverns, open halls, solemn churches, from the roof, the ground to the walls, from the hanging crystal clear chandeliers, to countless lifelike sculptures and icons, everything is made of unpretentious salt!

This is the pride of the Polish cultural heritage, which has been carefully maintained for centuries, and in 1978 the Wieliczka Salt Mine was included in the first UNESCO World Heritage List.

Today, the small town of Wieliczka, a dozen kilometers from the historic Polish city of Krakow, has a population of only 20,000 and receives more than 1.2 million tourists every year.

The salt mine has been around for more than 700 years

"The Wieliczka Salt Mine is 327 meters deep, has nine levels and a total length of 245 kilometers. Facilities in the mine include vertical tunnels, staircases, churches, lakes, and large and small outlets. It shows the various stages of the development of mining technology. This is a brief statement made by UNESCO when the Wieliczka Salt Mine was inscribed on the World Heritage List.

Descending the mine in a special old-fashioned elevator that could only accommodate less than 10 people, the descent was fast, and soon it was 64 meters underground.

Walking in the passage propped up with thick logs, the smooth gray stone walls shone with a slight light, shining with a flashlight, and in some places it was transparent, which was all crystalline salt! I stuck out my tongue and licked it, it was really salty. As he walked, Janus told us about the history of the salt mines.

The raw material sources of salt can be divided into 4 categories: sea salt, lake salt, well salt and mineral salt. The well-known sea salt is obtained by drying seawater as a raw material; The salt obtained from the salt lake is called "lake salt"; The salt prepared by sinking wells and drawing underground brine is called "well salt"; The salt produced from the mining of rock salt deposits is called "mineral salt".

Tens of thousands of years ago, some places were originally oceans or inland lakes. Later, due to the dry climate and high temperature, the seawater or lake water evaporated and crystallized into salt, and then through the change of sea and land, the sea basin and inland lakes became land, and the salt in the sea basin gathered together to form a salt mine.

Onshore salt mines are mainly rock salt, which is also called rock salt because it is produced in mountain rocks. The land of Wieliczka was a sea 13 million years ago, and then with the movement of the earth's crust, the sea became land, and the sea salt became rock salt.

The Wieliczka salt mine was discovered at the end of the 13th century. In the 16th and 17th centuries, the salt mines were called the "greatest possessions" of the Kingdom of Poland. In addition to being consumed by the Poles, the salt here is also exported in large quantities to other European countries.

Because the price of salt was as high as gold at that time, the income from salt produced in Wieliczka accounted for 1/3 of the Polish national income at that time, and the salt trade also led to the prosperity of port cities such as Gdansk. The Poles proudly proclaimed that the prosperity of medieval Poland was due to Wielicka.

There is a folk story that says that a Hungarian princess discovered a salt mine.

When Ye Chao walked into a mining cave, a group of eagles appeared in front of him: a woman wearing a crown was standing, her hands stretched forward. A man wearing a miner's hat and a pickaxe in his left hand knelt on one leg and handed the woman a small stone with a ring in his right hand.

This is the Hungarian princess Jinka, who is said to have discovered the Wieliczka salt mine.

A long time ago, the king of Hungary betrothed his beloved daughter, Princess Jinka, to the Grand Duke of Krakow in Poland. When the dowry was being prepared, the king asked his daughter what she wanted. The princess said that she wanted a salt mine, which would bring happiness and comfort to the Poles. Because at that time there were salt mines in Hungary, but not in Poland.

The king nodded in agreement.

The princess took off her engagement ring and threw it into a salt mine in Hungary.

When the princess and her party arrived on the outskirts of Krakow, Poland, she had a dream that there were salt mines here. On the second day, she sent her miners to Wieliczka, near Krakow, to open a mine. A miracle happened, the miners not only dug up the salt, but also had the ring that the princess threw into the salt mine in the first rock salt.

Princess Jinka brought salt to the Poles and also brought good times.

In this salt mine, the miners have used Princess Jinka as their patron saint for hundreds of years, and statues of her have been placed in many places.

It's such an amazing story, Princess Jinka is a bit like Princess Wencheng of China.

Most of the stories that have been handed down in the world are beautiful-Ye Chao thought.