If I were to point into the sky, how many galaxies would be in this line? If I point in the sky and draw a line from the tip of my finger to the end of the universe, how many galaxies would this line cross? I had a discussion with my dad and he said due to the universe being so empty the line wouldn't cross any solid matter. I said that the universe is so enormous in size that there would be many galaxies and stars crossing the line.
Is this calculable? If yes which one is correct?
Take a look at the "Deep field" image from Hubble: http://www.spacetelescope.org/science/deep_fields/

You can see in this tiny part of the sky, hundreds of galaxies, but between there is lots of dark sky. Most lines of sight don't end on a galaxy. I'd say dad was right. I would estimate, from the deep field, that you have about a 1/10 chance of pointing at a galaxy.

Even if your finger does point at a galaxy, the distances between stars are vast. Think of two footballs separated by the distance between Europe and China as a model for the distances between stars. A finger pointing at a galaxy would be unlikely to point exactly at one of the stars.

This is probably a Good Thing. Olber's paradox supposed that if each line of sight ended on a star, the night sky would be a uniform blaze of light.