木星の巨大な嵐「大赤斑」
Jupiter has a huge storm called the “Great Red Spot.” This storm is so big that two or three Earths could fit inside it! It has been going on for over 350 years, making it one of the longest-lasting weather systems in the solar system. The wind speed inside the storm can reach up to 430 kilometers per hour. Scientists are amazed by how long it has lasted. No one knows for sure why the spot is red, but it may be caused by chemicals in Jupiter’s atmosphere.
消しゴムの歴史
Erasers we use every day were originally made from natural rubber. In 1493, Columbus saw people in the Americas making bouncing balls from rubber and brought it back to Europe. However, natural rubber had problems?it became sticky in summer and hard in winter. In the 1950s, Japan developed plastic erasers using vinyl chloride, which are now commonly used.
パスタの起源と歴史
Pasta is known as a symbol of Italian cuisine, but some believe it originated in China. In the 13th century, Marco Polo is said to have brought noodles from China to Italy, where they evolved into modern pasta. However, dishes made from wheat flour existed in ancient Rome, indicating that pasta has a very long history.
世界で一番深い郵便ポスト
In Japan, there is a very special mailbox located underwater! It is in Susami Town, Wakayama Prefecture, and it is about 10 meters deep in the ocean. Divers can mail waterproof postcards from this mailbox. It was even recorded in the Guinness World Records as the world’s deepest mailbox. Many people visit this place to enjoy diving and sending unique underwater letters!
なぜ日本ではお辞儀をするの？
In Japan, bowing is a traditional way to show respect, say hello, thank someone, or apologize. This custom has a long history, starting over 1,000 years ago. During the time of the samurai, bowing was used to show honor and loyalty. Today, people still bow in schools, offices, and even on the street. There are different kinds of bows depending on the situation. The angle of the bow shows how respectful you want to be. Bowing is a very important part of Japanese manners and culture.
白熱電球の発明とその進化
The incandescent light bulb is widely attributed to Thomas Edison, but in reality, British inventor Joseph Swan secured a patent in 1860 for an incandescent lamp using carbonized paper as a filament. However, due to technological limitations, it was challenging to make it practical at that time. Swan continued to improve his design and achieved practical implementation by 1880. Meanwhile, in 1879, Edison developed a bulb using a carbon filament that could glow for about 40 hours. He further extended the bulb's lifespan to approximately 1,200 hours by utilizing bamboo filaments from Japan, significantly contributing to the widespread adoption of electric lighting.
カバの汗はピンク色！
Hippos are amazing animals with a very special trait ? they sweat pink! This pink sweat is not really blood, but it looks like it. The liquid helps protect their skin from the sun and bacteria. That’s why hippos don’t get sunburn even though they spend a lot of time in the sun. Scientists call this pink liquid “blood sweat,” but it’s just a nickname. It’s really a helpful kind of sunscreen and germ killer made by the hippo’s body.
自然にできる「丸い石」ってホントにあるの？
In some parts of the world, almost perfectly round stones can be found, and they were not made by machines. One famous example is the stone spheres of Costa Rica. These stones are between a few centimeters and 2 meters wide. Some scientists think that they were made hundreds of years ago, but no one knows exactly how. Some may have been shaped by nature, while others may have been made by people. Their round shape is still a mystery that researchers are trying to solve.
雷の音はなぜ遅れて聞こえる？
When you see lightning and then hear thunder a few seconds later, it's because light and sound travel at different speeds. Light travels extremely fast?about 300,000 kilometers per second. On the other hand, sound moves much slower, at about 340 meters per second in air. So when lightning strikes far away, the light reaches your eyes almost instantly, but the sound takes more time to reach your ears. This delay helps us estimate how far the storm is. For every 3 seconds between lightning and thunder, the storm is about 1 kilometer away.
静電気ってなぜパチッとくるの？
Have you ever felt a small shock when you touch a doorknob in winter? That is called <em>static electricity</em>. When we move, our clothes and body can collect tiny electric charges. This happens more often in dry air. When we touch something metal, like a doorknob, the electricity quickly moves from our body to the metal. That sudden movement causes a shock. It feels like a little spark and makes a zap sound!
なぜ空は青いの？
The sky looks blue because the air scatters sunlight. Sunlight is made up of many colors, like a rainbow. Blue light is scattered more than other colors because it travels in shorter waves. This makes the sky appear blue to our eyes. This effect is called Rayleigh scattering. In the morning or evening, the light travels a longer way, so red and orange light can be seen more easily. That’s why the sky turns red or orange at sunrise and sunset.
ライオンの「うなり声」は8キロ先まで届く！
Lions have one of the loudest roars among all big cats. Their roar can travel up to 8 kilometers (about 5 miles). They use their roar to mark their territory and to tell other lions, “This place is mine!” Male lions often roar at night because the air is cooler and sound travels farther. It’s their way of protecting their pride and showing strength, even when they’re not close by.
なぜコインは丸いの？
There are some good reasons why coins are round. First, round coins are easy to use in machines like vending machines. They also do not have corners, so they are safer and harder to break. Long ago, people found that making round coins was simple. Even today, round coins are used all over the world because the shape is very useful.
宇宙でも育つ植物の不思議
Plants can grow in space, too. On the International Space Station (ISS), astronauts grow vegetables and flowers. In space, there is no gravity, so roots and stems grow in different directions. But plants still grow toward light. Using this, astronauts can grow food like lettuce and tomatoes.
氷の中で眠るカエル
In Alaska, a frog called the wood frog can freeze in winter. Its body and even its heart stop working. But in spring, it wakes up again as if nothing happened. This is because it makes special sugars that protect its cells from ice damage. This amazing skill helps scientists study freezing and saving living things.
バナナはベリー？
A banana is a fruit, but it is also a berry in science. On the other hand, strawberries and raspberries are not real berries. This is because berries are fruits that come from one flower and have seeds inside the flesh. So bananas are berries, but strawberries are not.
ムクドリの見事な編隊飛行
In Europe, starlings gather in groups of thousands to perform complex aerial displays. This behavior is called "murmuration" and is believed to help protect them from predators and facilitate information exchange. Each bird adjusts its position and speed relative to a few nearby birds, creating impressive group movements as a whole.
光るキノコの森
Some mushrooms glow in the dark. This is called "bioluminescence." It happens when enzymes in the mushroom react with oxygen and make light. In Japan, there is a glowing mushroom called yakō-take. These mushrooms shine with a soft green light at night. Some people think they glow to attract insects to spread their spores.
