Do scientists/theorists say the universe has a finite size?

The Universe is defined in websters dictionary as "everything that physically exists: the entirety of space and time, all forms of matter, energy and momentum, and the physical laws and constants that govern them." Though im not sure if i would personaly say I agree with this. Because through our advancment to know "everything" we have come to learn that also within the confines of the universe consists not only physical matter, but non-physical negative matter. As for a boundry of space and time. I believe there is. Just as time ends so should space. For example. Our solar system is only a raindrop in the ocean of space. And as time moves on it too shall someday end. Everything ages. atoms age and die. Neutrons age and die. As I believe so should space. Everything in exsistance consists of atoms, Ions, and Neutrons. All of which have a "life time" of their own. They are born and they die. So in my belief, all things that begin must end somewhere, Someday.