What is physics?
Physics is the study of matter and energy and how they relate.
Physics is what you use to predict where something is going to be, how fast and in what direction it’s going to move and how its motion will change at times in the past present and future.
Physicists study the forces that make things change how they move or resist such changes, keeping things still.
What things? Any things. From electrons and atoms to planets, stars and galaxies to everything in between. Cars, baseballs, you and me.
Physics is the study of energy. Energy is in moving things, it’s in things that can be moved by forces, it’s in things because of their temperature, it’s in light because of what color it is.
Physics is the study of momentum and collisions – how do things behave after they have run into one another, or when they explode.
Physics is the study of electricity, of static cling, of current and voltage, of why electrons are attracted to the nuclei of atoms and how molecules are attracted to each other. Physics is the scaffolding for chemistry. Chemistry and physics are what lie behind biology.
Physics is chemistry. Physics describes and tries to explain the structure of the atom, the attractions between molecules the ways gasses behave, how much energy is needed to heat, melt and boil a substance.
Physics is the study of light. Physics explains why the sky is blue, and the sun looks yellow most of the time, but looks red at sunset. Physics is behind how infrared cameras work.
Physics explains why a heating element in a stove glows red, and then orange as it gets warmer. Physics describes how your eye lens, camera lens, contact lens, prisms and rainbows work.
Physics is music. Physics describes how a radio works. Physics describes how soundwaves travel and are formed, how they relate to pitch, how that pitch changes if things move, like when a racecar zooms past the microphones at a track, or an ambulance passes by. Waves in the air, waves in the Earth – physics describes earthquakes, and the convection of magma rising up through the mantle, and falling again driving the motions of the plates.
Physics is the universe. How do stars shine? How do we know how far away they are? How far away galaxies are? How old they are? How old the universe is? Physics is used to answer questions like these.
In all of these things, physics tries to root its predictions and descriptions in as simple a way as possible. Sometimes it’s not so simple! But physics tries to reduce its descriptions to basic fundamental principles whenever possible.
Physics uses math. Physics class attacks many of these ideas using math word-problems.
552 Physics (CP1) touches upon many of these ideas,
554 Honors Physics approaches some of these ideas, and AP Physics addresses many more of them.