What is the universe expanding into?

Nov 28, 2013 by Fraser Cain, Universe Today

Representation of the timeline of the universe over 13.7 billion years, and the expansion in the universe that followed. Credit: NASA/WMAP Science Team

Come on, admit it, you've had this question. "Since astronomers know that the Universe is expanding, what's it expanding into? What's outside of the Universe?" Ask any astronomer and you'll get an unsatisfying answer. We give you the same unsatisfying answer, but really explain it, so your unsatisfaction doesn't haunt you any more.

Come on, admit it, you've had this question. "Since astronomers know that the Universe is expanding, what's it expanding into? What's outside of the Universe?" Ask any astronomer and you'll get an unsatisfying answer. We give you the same unsatisfying answer, but really explain it, so your unsatisfaction doesn't haunt you any more.

Read more at: http://phys.org/news/2013-11-universe.html#jCp