Why is the definition of “matter” on Wikipedia something that both consists of mass and volume?
In the context of science, people generally talk about the “matter and energy in the universe.” So it would appear that the definition of matter must be such that it precludes the inclusion of energy. Like a gas, energy can occupy a volume. Think of the end of a cold rod with one end touching a hot surface. Heat (energy) diffuses from the hot surface into the body of the rod with finite speed. Over time, the entire volume of the rod is brought to the temperature of the hot surface. Clearly, the percent volume occupied by the energy flowing in increases over time. However, unlike the material of the rod, the heat energy has no mass. The mass of the rod doesn’t change as it is heated. So by requiring both mass and volume in the definition, energy is precluded from the definition of matter. === Wavelengths are associated with waves. Waves are how energy is transmitted through space. So wavelengths tend to be associated with discussions of energy. However, waveforms also have wavelengths.
