Fun and Fun

 Fun and Fun

 

1. Giant Tube Worms

In 1976, scientists found strange animals on the floor of the Pacific Ocean. They saw a beautiful landscape that looked like chimneys expelling dark-colored water—often called “black smoke.” The water coming out is nearly 400°C. Around these chimneys live unique giant tube worms. These strange animals can be 8 feet tall. They have no mouth and no digestive tract. Bacteria living inside the worms make food for them. Millions of shrimp are also found near the vents.

2. Black Smokers

On the floor of the Pacific Ocean are vents, or cracks. Seawater seeps down into Earth’s crust through the vents. The water is heated by magma below the crust until it boils. It expands and rises back to the surface through the same vents. The hot water dissolves minerals and other chemicals in the rocks. When it reaches the ocean floor, the water is dark. Some minerals harden on the rim of the vent. Over time, the rim builds up into a tall chimney. The dark color of the water coming from these vents gives them the nickname “black smokers.”

3. Atolls

What are atolls? When a volcano erupts in the ocean, it forms an island. Coral animals build reefs around the island. Over thousands of years, the reefs keep growing while the volcanic island sinks or erodes, leaving behind a ring-shaped reef called an atoll. The largest atoll in the world is Kiritimati, also called Christmas Island, in the Pacific Ocean. It is part of Kiribati and has its own flag and postage stamps.

4. The Great Barrier Reef

The Great Barrier Reef is the world’s largest coral reef system. It runs along the northeastern coast of Australia and is about 1,500 miles long. It can be seen from space. Nearly 6,000 species of animals live on the barrier reefs. Barrier reefs are made by groups of tiny coral animals living together. When corals die, they leave behind stony skeletons, which accumulate to form a reef.

5 Our Ancient Ancestors

While describing the fossil record, Charles Darwin wrote that the crust of the earth is a vast museum. For about 150 years, paleontologists have been searching that collection. Recently, many fossils have been collected from a valley in Ethiopia whose sediments span 6 million years. One of the masterpieces is a 4.4-million-year-old skeleton of *Ardipithecus ramidus*, one of the oldest and most complete early human relatives. It predates Lucy by 1.2 million years. “Ardi” is a four-foot-tall female skeleton. Ardi was at home in trees, but she also walked upright. This fossil finding filled a big gap in human history.

6. Icy Bodies

When solid lumps of carbon dioxide—dry ice—fall into water and warm up, they make swirling, misty patterns. Most frozen things warm up from solid to liquid and then to gas. Dry ice changes straight from a solid into a gas: it sublimes. As lumps of dry ice sublime, jets of cold gas shoot out. This makes the lumps spin around, creating a beautiful pattern of swirling. Sublimation is a process in which a solid changes directly into vapor.

Fun Extras

- **Lions:** A lion’s roar can be heard from several miles away.

- **Zebras:** Zebras can sleep standing up, but they often lie down for deeper sleep.

- **Giraffes:** Giraffes sleep very little compared with most mammals—often in short naps.

- **Elephants:** Wild elephants can get by on surprisingly little sleep.

- **Horses:** The leg-locking system that lets horses doze standing up is called the “stay apparatus.”

- **Giant tube worms:** Their red plume contains hemoglobin, the same oxygen-carrying molecule that makes human blood red.

- **Black smokers:** The water is about 400°C but does not boil at that depth because of high pressure.

- **Atolls:** An atoll is a ring-shaped coral reef, often surrounding a lagoon.

- **Great Barrier Reef:** Coral looks like rock, but it is made by living animals called polyps.

- **Ardi:** Ardi’s skeleton suggests she could climb in trees and walk upright.

- **Dry ice:** The fog from dry ice is mostly condensed water vapor in the air, not carbon dioxide gas itself.