Question

What is the meaning of dark in physics. Example= Dark matter, Dark energy, etc.​

Answer 1

Dark matter is called dark because it does not appear to interact with the electromagnetic field, which means it does not absorb, reflect or emit electromagnetic radiation, and is therefore difficult to detect

Dark matter could be white dwarfs, the remnants of cores of dead small- to medium-size stars. Or dark matter could be neutron stars or black holes, the remnants of large stars after they explode.