Expansion of the Universe

This just came to me out of the blue. I remember in physics class that the Universe was expanding. And then I would later read this in magazines and books and also watch it on television.

What in the WORLD is the universe expanding into? Has anyone ever thought of what is outside the universe or if it ever stops? And if it stops, what else follows it? Is it an infinite thing?

These are all questions that amuse me. What about blackholes, are they really a portal through time or a collapsed star or whatever it is? What happens when something enters it? I know I'm going to leave some people hear amused and wondering the same things that I am wondering.

What about time travel? Does that exist? I heard on the radio last night that a scientist was about to ignite some type of laser or photon and capture it into a box or something like that and before he flipped the switch, the photon had already gone through the device. He then flipped the switch. I forget who did it, but that could have been some type of time travel.

Happy researching.