Question

list something that is not considered to be matter

Answer 1

Here are some things that are not considered matter, with a brief note for each:

- Light (electromagnetic radiation, photons) — carries energy and momentum but has no rest mass.
- Heat — a form of energy transfer, not a substance.
- Sound — a mechanical wave (pressure disturbance) traveling through matter, not matter itself.
- Electric and magnetic fields — physical fields that exert forces and carry energy, not particulate matter.
- Gravity (gravitational field/waves) — curvature of spacetime or propagating waves, not matter.
- Vacuum (empty space) — absence of matter (though it can have fields and energy).
- Time — a dimension, not a material substance.
- Information/ideas — abstract entities, not composed of matter.