Gong: The sentence you refer to is discussing the Moment---of---Singularity, associated with the "Big Bang". The Cosmos (the term that replaces "universe") that you seen not, is "expanded". Prior to it expanding, 13.8 Billion years ago, the Cosmos was reduced in size, compact or compressed to a degree that is almost incomprehensible. The diagram at this link offers a visual of compact or compressed matter and energy. http://en.wikipedia.org/wiki/Big_Bang

compaction increases the density of an object. the more dense an object is the more mass it fits into a space. a bucket of dirt holds more if you compact it or compress it.