《Hanji, Korea's Paper》 Until 1966, no one knew that the Mugujeonggwang Daedaranigyeong, the world's oldest printed document, lay inside a container at Bulguksa Temple in Gyeongju, Korea. Experts around the world were shocked that a document printed more than 1,200 years ago could still be around. They were even more surprised when the paper was removed from the container. Although the document was printed before 751 CE, it was still in perfect condition. This discovery proved that the paper-making technology of the Unified Silla Kingdom era (676-935) was more advanced than that of either Japan or China, both of which also had highly developed paper-making technology. How could this paper last for more than 1,000 years without breaking down or becoming damaged? The secret lies in hanji's amazing physical properties.

Hanji is traditionally made from the bark of the mulberry tree. Through a number of complex processes, the tree bark is made into a paper that is very durable and hard to tear. On the other hand, Western paper, which is made from pulp, begins to fall apart and becomes unusable after 100 years. It's easy to understand why Koreans created the old saying about hanji; "Paper lasts a thousand years, while silk endures five hundred." In addition to lasting a long time, hanji keeps heat and sound in but allows air to flow through it easily. The paper also absorbs water and ink very well, so there is no bleeding.

Because of hanji's characteristics, Koreans could see early on that it was more than just something to write on. Since ancient times, they have glued this paper to the walls, door frames, and floors of their homes. Koreans have also used it to make furniture, lanterns, wedding accessories, and boxes. Due to its durability, hanji was even used in battle. Back then, people would put many layers of hanji together to make suits of armor. This armor, called jigap, was tough enough to stop arrows. With so many uses, hanji is naturally considered an invaluable part of Korean history and culture. Though the tide of modernization seems to have made people forget about this paper's outstanding qualities, hanji has endured and remains relevant today. In recent years, finding even more functions and purposes for hanji has become a trend.

Lately, designers have been using hanji to make clothes, socks, and ties. The fabric these designers are using is a blend of hanji yarn with cotton or silk. This blend is almost weightless and keeps its shape better than other materials. It is also washable and eco-friendly. Not only is hanji clothing practical, but it's also making waves at domestic and international fashion shows. It seems that hanji clothing is here to stay. One of hanji's newest uses is a treat for the ears. Customers can now buy speakers that use vibration plates and outside panels made of hanji. Compared to regular speakers, the sound that comes from hanji speakers is stronger and sharper. The paper's thickness and ability to absorb sound help the speakers pick up the smallest vibrations. In addition, the fact that the sound will not change over time because of the strength of hanji makes these speakers a great purchase. Serious music lovers will really be able to appreciate the great sound quality of these speakers.

And now, in one of its most innovative uses yet, hanji may soon be traveling into outer space. Korea and the U.S. are planning to use hanji on robots and spacecraft through a joint project supported by NASA. The paper has special properties that will help protect spacecraft from the harmful rays of the sun. Scientists hope to use hanji in the future for space probes since it is less expensive and lighter than the currently used materials. As you can see, people keep transforming hanji for countless uses. Its ability to adapt to the needs of every generation has led to the revival of this traditional paper. So long as hanji continues to be treasured, there may be no limit to how it will be enjoyed in the future.

《How Teens Make Decisions》 Host: Hello, everyone! Welcome to The Dr. Brain Show. I'm your host, Joseph Emerson. Can you think back to a time when a friend upset you? Let's imagine that you decided to write an angry message to that friend. You say some harsh things that you normally wouldn't say. You're so angry that you don't care. When you're about to push "send," you think about whether it's a good idea. Before you know it, you've sent the message anyway. Teens are more likely to make these types of decisions than adults. With the help of our guest, we'll learn why teens tend to act before thinking everything through. Now, here's our guest for tonight, Dr. Jenny Clarkson! Thank you for joining us, doctor! Dr. C: Thank you for having me, Joseph!

Host: Dr. Clarkson, could you first tell us about how we make decisions? Dr. C: Sure, It seems like we make decisions almost immediately, but our brain actually has to go through several steps before deciding anything. Neurons, which are special brain cells, make up different structures in our brains. These structures send signals to each other. After the structures finish evaluating all the signals, they will send out a response that will tell our body what to do. Host: I see. Does this process happen exactly the same way in everyone's brain? Dr. C: People basically go through the same decision-making process, but there is a slight difference between teens and adults. Scientists used to think that the brain was done growing by the time you turned 12 since the brain reaches its maximum size around that age. However, studies show that some parts of the brain continue to develop until the early twenties. That means teens' brains are still maturing and not completely developed. This may be why teens seem to make risky decisions.

Host: Very interesting! Please tell us more about the relationship between their brains and their decision-making. Dr. C: Well, the region that controls emotions matures faster than the part of the brain that helps you think ahead and measure risk. Teens therefore rely on it heavily, which means they are influenced more by feelings and instincts than by reason when making decisions. In other words, teens are usually not inclined to consider all the consequences of their actions, so they make choices that they end up regretting. Host: So what you're saying is teens are likely to make choices based on their feelings since their brains are not fully developed.

Dr. C: That's right. However, this is not the whole story. Teens' brains are also going through other important changes. Their brains are constantly identifying and removing any weak connections between neurons. For example, if teens aren't reading, doing experiments, or solving problems, then the brain will get rid of the connections that are related to those activities. Once those are gone, their brains will put more energy into making other connections stronger. Host: So, do you mean that the activities teens are involved in can shape the way their brains develop? Dr. C: Exactly, This is why the types of activities teens choose to participate in are especially important. If a teen decides to play sports or learn an instrument, then the brain will strengthen those connections. On the other hand, if he or she chooses to surf the Internet or play online games all day long, then those connections will survive instead. The harder teens work at building good habits, the stronger those connections in their brains will be.

Host: I see. Do you have any final comments for our viewers? Dr. C: If we view the adolescent period as merely a process of becoming mature, then it's easy to dismiss it as a passing phase. However, we shouldn't look at the changes that occur in teens' brains only in terms of maturity. Adolescence is also a period when significant changes happen in the brain that help new abilities appear. Therefore, adolescence is not a stage to simply get through, but an important stage in people's lives where they can develop many qualities and abilities, and shape their future. Host: Thank you for your insight, Dr. Clarkson! We hope the information you've shared will help our viewers at home make more reasonable choices in the future. That's it for The Dr. Brain Show tonight. Good night, everyone!