The Invisible Glue Holding Galaxies Together
Dark matter is the invisible glue that holds the universe together, making up most of the matter in it. NASA estimates ordinary matter is only about 5%, dark matter about 27%, with dark energy making up the rest. It interacts with ordinary matter through gravity, but it does not seem to interact with the electromagnetic spectrum—so it does not absorb, reflect, or emit light. That is why we infer it from how it shapes galaxies and cosmic objects. The name is a useful confession: “dark” means we do not see it, and “matter” is the best guess for something that shows up mainly through its gravitational influence.
AI-generated discussion · Different perspectives
The name is a confession: “dark” means we do not see it, and “matter” is the best guess for something that only shows up through gravity.
Calling it glue makes it sound settled. The percentages are estimates, and the rest—dark energy—is another open question.
Fair. The useful part is the method: we detect it by its gravitational influence, not by light.