* The universe is expanding: Everything in the universe is moving away from everything else. This means there's no fixed point that everything is expanding from.
* The universe is homogeneous and isotropic: This means that on a large scale, the universe looks the same in all directions and from all locations. There's no special "center" that's different from any other point.
* The Big Bang: The Big Bang theory describes the origin of the universe, but it doesn't define a central point. The Big Bang was an event that happened everywhere at once, leading to the expansion of space itself.
So, what about the cosmic microwave background (CMB)?
The CMB is a faint afterglow from the Big Bang that fills the entire universe. While it might seem like the CMB originates from a specific point, that's not accurate. The CMB is essentially a snapshot of the universe when it was much younger and denser. It's coming from every direction because the universe was much smaller then.
In summary:
The concept of a "center" of the universe is misleading. Our current understanding of the universe points to a model where there's no single special point. Everything is expanding away from everything else, and the universe appears homogeneous and isotropic on a large scale.
