Millions of light-years apart.
There are more and more galaxies for as far as we can see.
In light years (how far light travels in a year) light travels at about a billion km/hr.
yes
Far apart.
how far apart is the untied states from Algeria
Quite far apart I'd say. There is an ocean in between.
About 30.
Ultraviolet
At its centre.
The same thing that keeps the Solar System from moving apart, and that keeps the Moon in orbit around Earth: gravity. In the case of galaxies, usually at least 80% of the gravity is from invisible dark matter.
The place in a wave where particles are far apart is called a crest.
The path of univers's galaxys