In Laos, there is a place called the Plain of Jars. It has thousands of big stone jars. Local stories say giants used them to store rice wine. Some people thought they held food and water. Now scientists say the jars were used for burial. They found bones of at least 37 people inside one jar. The bones are over 1,000 years old. This jar is more than two meters wide. It is in a forest in northern Laos. Scientists think the jar was a burial site for many generations. People may have first put bodies in smaller jars. After the flesh came off, they put the bones in the big jar. This is called a secondary burial. The discovery helps solve a long mystery. Earlier explorers thought the jars stored food. But a French archaeologist named Madeleine Colani said they were for burial. New studies show she was right. Some jars also had ashes from burned bones. That shows later people used the jars for cremation. Scientists are still learning about the people who made the jars. They wonder where those people lived.

Gold stays shiny forever. Other metals like steel and copper can rust or turn green. Scientists now know why gold does not rust. Rust happens when a metal meets oxygen. Gold atoms on the surface move into a new shape. This shape makes it hard for gold to react with oxygen. If gold atoms did not move, gold would start to rust in seconds. Researchers studied two common shapes of gold atoms. One shape is squares. The other shape is hexagons. Hexagons are worse at splitting oxygen. To split oxygen, hexagons must change back to squares. That slows down rust a lot. It makes oxidation a billion to a trillion times slower. This finding could help scientists make better catalysts. Catalysts speed up chemical reactions.

Some mice can sing. They are called Alston's singing mice. They live in forests in Mexico and Central America. These mice make whistling sounds. They use small air sacs in their throats. The sacs are like balloons. When the mice blow air into them, they make music. The songs are fast and long. A mouse can sing about 100 notes in just 10 seconds. The songs help mice find friends and warn other mice to stay away. Scientists wanted to know how the mice sing. They studied the voice box of the mice. The voice box is a tube with a valve. When air goes through, the sac puffs up. If the sac is blocked, the mouse cannot sing. This shows the sac is very important. Other animals have air sacs too, but they do not use them to sing. The scientists are not sure how the sac makes the whistle sound. It might be like wind blowing past a car sunroof. Or it might be like a flute. The mouse song is special because the sac itself makes the sound. This is different from other animals. Learning about this helps us understand how animals talk to each other.