What is physics? Physics is one of the oldest sciences, studied for thousands of years. In the simplest terms, physics is the study of matter and energy, and how they interact. A physicist uses scientific methods to try to make sense of the natural world.

A Matter of Matter

Physics covers a wide range of topics, as physicists study everything from the tiny particles that make up an atom to huge planets and everything in between. Anything that takes up space is made of matter: your pencil, the dust under your bed, the steam rising from a mug of hot chocolate, your dog, even the air that fills a balloon. Anything you can see, even if it's not solid, is made of matter.

Physicists study how that matter moves and changes. This is where the energy part comes in. This energy can be motion, but physicists also study other kinds of energy as well, including electricity, gravity and light. The reason your ball rolls down a hill, or paper clips jump onto a magnet or your kite flies in the sky can all be explained with physics. Think of it like this: matter is what makes up everything, and energy is what causes matter to change. Everything around us is affected by physics.

Studying Physics

Because the study of physics is so vast, most often a physicist will focus on a specific area, such as biophysics (the study of living things), astrophysics (the study of objects in space), molecular physics (which studies how matter is formed) or quantum physics (the study of tiny subatomic particles). Often these disciplines will overlap. Sometimes the study of physics will overlap into other areas of science, like chemistry or biology, as well.

So why do we study physics? By learning physics and understanding its principles, we can gain a better understanding of our world and how it works. We can learn why our flashlight sends a beam of light into the dark, or what the pendulum on a grandfather clock does.

Physicists come up with theories to try to explain things we can't see so easily, such as the formation of our universe, or what goes on inside an atom. Engineers work closely with physicists, as new discoveries in physics help to create the things we use every day, from the microchips that run your computer to the glue that's found in sticky notes.

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