Subsection 14.1.6 Dark Matter and Dark Energy
Dark matter and dark energy are two of the most mysterious and intriguing components of the universe. Dark matter is a type of matter that is thought to make up about 27% of the total matter content of the universe. It is called "dark" because it does not emit, absorb, or reflect light, making it invisible to telescopes and other instruments that detect electromagnetic radiation. The presence of dark matter is inferred from its gravitational effects on visible matter, such as stars and galaxies. Dark matter is believed to play a key role in the formation and evolution of galaxies, as well as the large-scale structure of the universe. Dark energy is a hypothetical form of energy that is thought to make up about 68% of the total energy content of the universe. It is called "dark" because, like dark matter, it is invisible to telescopes and other instruments that detect electromagnetic radiation. The existence of dark energy is inferred from observations of the accelerating expansion of the universe. Dark energy is believed to be responsible for this acceleration, although the exact nature of dark energy is not yet well understood. Together, dark matter and dark energy are thought to make up about 95% of the total matter and energy content of the universe, with the remaining 5% consisting of visible matter, such as stars, galaxies, and interstellar gas and dust. The study of dark matter and dark energy is a major area of research in cosmology, and scientists are working to understand their properties and how they influence the evolution and fate of the universe.
