氷の声が響く場所
In glaciers like those in Antarctica and Greenland, ice can make loud sounds. These sounds come from cracking ice, moving layers, and trapped air. The noise can be like "bang" or "rumble." Scientists record these sounds to study glacier movement and climate change.
ライターとマッチの意外な歴史
Many people think that matches were invented first, and then lighters were made. However, in reality, lighters were invented earlier. The lighter appeared in 1772, while the match was first invented in 1827. This means lighters existed more than 50 years before matches.
キリンの高血圧の秘密?
Giraffes are the tallest animals on land, with necks that can be about 1.8 meters long. To pump blood up such a long neck, their hearts are very strong and have high blood pressure. In fact, giraffes have the highest blood pressure among animals, reaching about 280/180 mmHg. This is about twice as high as a typical human blood pressure.
海の音の道筋
In the ocean, there is a "sound channel" where sound waves are naturally guided over long distances. This occurs because water layers with different temperatures and salinities cause sound waves to bend and get trapped at a certain depth. Submarines often use this channel for communication, sending low-frequency sounds that can travel hundreds of kilometers.
チンギス・ハンと郵便システム
Genghis Khan, the founder of the Mongol Empire, created an amazing postal system called "Yam." This system used horse riders who changed horses at stations placed every 40 km. It allowed messages to travel quickly across the vast empire. Thanks to Yam, the Mongol army could receive orders fast and rule their lands effectively. This system was an early version of modern postal and communication networks.
宇宙で最も大きな火山
The biggest volcano in the solar system is Olympus Mons on Mars. This volcano is about 22 km tall, which is about 2.5 times higher than Mount Everest on Earth (about 8.8 km). Also, Olympus Mons has a diameter of about 600 km, which is half the size of Japan. This volcano is very old and is believed to be inactive now, but its size is truly amazing.
ローマ帝国のコンクリート技術
Ancient Romans had a special technique to make very strong concrete. In fact, their concrete is more durable than modern concrete, and some buildings have lasted for over 2000 years. Their secret was mixing "volcanic ash" into the concrete. This made it stronger over time. For example, parts of the Pantheon and the Colosseum still stand today because of this special Roman concrete.
世界で最も短い戦争
The shortest war in history was the Anglo-Zanzibar War. It happened on August 27, 1896, between Britain and Zanzibar. The war ended in just 38 minutes because the British military was much stronger. The Zanzibar forces quickly surrendered. This war is recorded in the Guinness World Records as the shortest war ever.
世界最古の大学はどこ？
The world's oldest university is not in Europe but in Africa. The University of Al-Qarawiyyin in Fez, Morocco, was founded in 859 and is still running today. This university has taught Islamic studies, mathematics, astronomy, and more, producing many scholars. It is recognized by the Guinness World Records as the "oldest existing university." It is over 200 years older than the University of Bologna, the oldest in Europe, founded in 1088.
砂漠に雪が降る？
People think deserts are always hot, but in winter, temperatures can drop below freezing. Snow was first seen in the Sahara Desert in 1979, and it has snowed a few times since then. At night, the temperature falls quickly, making it very cold. Deserts have a big difference between daytime and nighttime temperatures, so sometimes, snow can appear.
宇宙でのくしゃみ
When astronauts sneeze in space, the particles float around because there is no airflow. To keep their helmet clean, they close their eyes and face downward when sneezing. In a zero-gravity environment, objects can float, so the force of a sneeze can push an astronaut slightly backward. Something ordinary on Earth requires special precautions in space.
火星の夕焼けは青い？
On Earth, sunsets look red or orange, but on Mars, they appear blue. This happens because tiny dust particles in Mars’s atmosphere scatter blue light more than other colors. On Earth, the atmosphere allows red light to pass through more easily, making sunsets red. But on Mars, the effect is reversed. If you stood on Mars and watched the sunset, you would see a strange sight—an orange-red sky during the day turning blue in the evening.
火星での1日は地球より長い
A day on Mars is a little longer than a day on Earth. It is about 24 hours and 39 minutes. Because of this, NASA scientists working on Mars missions sometimes follow "Mars time." But since a day on Mars is longer, their schedule shifts about 40 minutes every day. After a few weeks, day and night can be reversed! This makes it very difficult to adjust.
ナポレオンとウサギの戦い
The French Emperor Napoleon Bonaparte was once attacked by a huge group of rabbits. One day, he wanted to enjoy hunting and told his men to gather rabbits. However, they brought tame rabbits instead of wild ones. When the hunt started, the rabbits did not run away. Instead, they thought they would get food and rushed toward Napoleon. Surrounded by thousands of rabbits, he was so surprised that he had to escape in his carriage.
ジーランディア大陸：失われた第七の大陸
We usually learn that there are six continents in the world: Asia, Africa, North America, South America, Antarctica, and Europe. However, there is actually a seventh continent called "Zealandia." Zealandia includes a vast area that encompasses New Zealand and New Caledonia, with about 93% of it submerged beneath the ocean. Due to its geological characteristics, it is recognized as a continent, but since most of it is underwater, we cannot see it.
南極には時間帯がない？
The world has many time zones, but Antarctica has no official time zone. This is because all longitudes meet there. So, different countries and research stations use different times. For example, American stations use U.S. time, while New Zealand stations follow New Zealand time. This can be a little confusing for travelers and researchers!
南極は世界最大の砂漠！？
When you hear the word "desert," you might imagine a hot, sandy place. But actually, Antarctica is the largest desert in the world. A desert is a place that receives less than 250 mm of rainfall per year. Antarctica is a land of extreme cold, but it is also very dry, with almost no precipitation. Its area is about 14 million square kilometers, which is much larger than the Sahara Desert (about 9.2 million square kilometers). So, Antarctica is an "ice desert"!
世界で最も深い青い穴
The deepest "blue hole" in the world is the Dragon Hole in the South China Sea. It is about 300 meters deep, which is enough to fit the Eiffel Tower inside. A blue hole is a deep, vertical hole in the sea floor, usually formed by the collapse of limestone. For divers and scientists, it is an important place to study marine ecosystems.
