Astrophysics
What Is Dark Matter, and Why Can’t We See It?
Most of the matter in the universe is invisible. We cannot see it, touch it, or make it in a lab, yet without it galaxies would fly apart. Here is what dark matter is.
What Is a Black Hole, and What’s Inside One?
A black hole is a place where gravity wins so completely that even light cannot leave. Here is what they are, how they form, and the honest answer to what lies inside.