It’s easy to define matter, yet harder to explain phenomena that are not matter. Matter is anything that has mass and takes up space. This includes atoms, elements, compounds, and any object you can touch, taste, or smell. Things that are non-matter either have no mass or else don’t fill a volume. Here are several examples:
- Vacuum: By definition, a vacuum is a region that does not contain any matter. It may be bounded by a volume.
- Energy: Light, heat, kinetic and potential energy, and sound are non-matter because they are massless. Objects that have mass and are matter may emit energy. For example, a swinging pendulum consists of matter, but its energy of motion is not matter. A fire consists of hot gases and plasma (matter), yet gives off light and heat (not matter).
- Time: Time can be measured, but it has no mass and occupies no volume.
- Rainbow: A rainbow is an optical phenomenon. It’s essentially light.
- Emotions: Love, hate, and happiness may be rooted in chemistry, but feelings don’t have mass or occupy volume.
- Gravity: You can feel its effects and it is associated with mass, yet it doesn’t consist of matter.
- Memories: Like emotions, these are non-matter.
- Dreams: Again, you can’t weigh them on a balance or enclose them in a container.
- Magnetism: Forces, in general, are not matter.
- Information: Information may be recorded in a physical form, but it’s really just a concept.
- Music: Music is sound, which is a form of energy.
How to Tell Something Isn’t Matter
There are two simple tests you can perform to tell if something consists of matter. If it fails either test, it’s non-material.
- Could the phenomenon be weighed on any scale? Matter has mass.
- Does the phenomenon occupy a volume? In other words, does it take up space? All matter has physical dimensions.
Note, your senses aren’t always reliable indicators of whether or not something is matter. You can see light and feel heat, but they don’t have mass. You can hear music, but you can’t weigh it or enclose it. Two senses you can trust are smell and taste. These two senses require chemical receptors. All scents and flavors are chemical compounds, which are matter.