Observable Universe Spans 92 Billion Light-Years

The observable universe is about 92 billion light-years across, even though the universe is only 13.8 billion years old. That looks impossible, because light cannot have traveled farther than 13.8 billion light-years.

Expansion explains it. The most distant galaxies we see emitted their light about 13.5 billion years ago. While that light crossed space, space itself stretched. Those galaxies moved far beyond where they were when the light left. They are now much farther away than 13.5 billion light-years. The 92 billion figure is today’s distance from edge to edge, not the distance the light traveled. Light from regions beyond that edge has not had time to reach us.