• Question: What is the "visible universe" and how big is it?

    Asked by Danielg to Adrian, Gaia, Jim, Scott, Vicky on 15 Mar 2016.
    • Photo: Scott Lawrie

      Scott Lawrie answered on 15 Mar 2016:

      The universe is 13.6 billion years old and 91 billion light years across. So those are the times and distances we can see. That’s because light takes a certain time to get to us. The universe is actually infinitely big, it’s just the light from outside that 91 billion LY bubble hasn’t got to us yet. That’s why we say ‘visible universe’. Does that make sense? 🙂

    • Photo: Jim Barrett

      Jim Barrett answered on 15 Mar 2016:

      The visible universe is about 91 billion lightyears across, but most of the universe is invisible, made up of mysterious dark matter and dark energy. Those are bad names, because we have absolutely NO idea what they are, and we can’t see them.

      The ‘visible universe’ is the 5% or so of the universe we CAN see.

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