Summary:
- The article discusses the mystery of where most of the normal matter in the universe is located. Normal matter refers to the familiar atoms and molecules that make up planets, stars, and galaxies.
- Observations suggest that only about 5% of the universe is made up of this normal matter, while the rest is composed of dark matter and dark energy, which are not yet fully understood.
- The article explains that astronomers are using various techniques, such as studying the cosmic microwave background and the distribution of galaxies, to try to locate and understand the missing normal matter in the universe.