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galaxies

A galaxy is a system of dust, gas, and stars that collects over a very large area. Gravity binds the objects in a galaxy together. Within each galaxy are billions of stars. ... read more

people who study animals

There are many things about animals that can be studied. We study their anatomy, their behavior, and how they live in the wild. We also learn more about our own bodies, behavior, and development when we look at other animals. We study how animal life can have an affect on humans and how humans can hav... read more

the solar system

A solar system is a group of planets and one or more stars. Our solar system has just one gigantic star, the Sun. It also has eight planets and three dwarf planets. Many planets have their own moons. There are also thousands of asteroids, meteoroids, and comets. Gravity from our huge Sun holds the sol... read more

what is chemistry

Chemistry is the study of substances and the changes that happen to them. Substances are things like food, clothes, and medicine. Chemistry is very important. Plastic bags and shoes with rubber soles would not exist without chemistry. Fuels for cars, airplanes, and rockets would not exist without chem... read more

why are circles 360 degrees and not a round number

Circles have 360 degrees due to the Sumerians’ observations of the Sun’s motion across the sky. ... read more