There's nothing between the galaxies. It's just other galaxies that float around the universe.
The space in between galaxies is far larger than the galaxies themselves.
Yes, there are stars between galaxies. When there are collisions or interactions between galaxies, stars can be ripped out of the galaxies. These stars will then wander into space between galaxies. Such stars have been observed with the Hubble Space Telescope. Taken from http://curious.astro.cornell.edu/question.php?number=384
Have no real effect on the merging "colliding" galaxies
a dinamiter of 800,00
Yes, lenticular galaxies are lens-shaped. They will not have spiral arms.
Eliptical galaxies have older stars than spirals and elipticals are oval-shaped.
Spiral galaxies get their beautiful structure from tidal interactions between galaxies.
Between them.
For starters, if there were no separation between two (or more) galaxies, it would be considered a single galaxies, not two or more. The reason matter is clumped together into galaxies at all (with separations in between) is because of gravity - gravity tends to do that, i.e., to clump things together.
billions of miles.
As the universe expands, the density of galaxies decreases. This is because the space between galaxies increases as the universe expands, leading to a lower concentration of galaxies in a given volume of space.
Like our galaxy contains billions of stars, the universe contains billions of galaxies.