Question

Dark matter does or does not absorb light does or does not admit radiation and has not or has been observed directly

Answer 1

Dark matter does not absorb light and does not emit radiation, which is why it cannot be observed directly. Instead, its existence is inferred from its gravitational effects on visible matter, such as galaxies and galaxy clusters. While dark matter has not been observed directly in the way that normal matter can be observed, its presence is supported by a variety of astrophysical evidence, including the rotation curves of galaxies, gravitational lensing, and the cosmic microwave background radiation.