<iframe width="580" height="385" src="https://www.youtube.com/embed/Rdr-KZChM00?autoplay=1" frameborder="0" allowfullscreen></iframe> <br>The Universe has been expanding ever since the Big Bang, but what is it expanding into? For more videos from BBC REEL visit: http://www.bbc.com/reel/ ... <br><a href="https://www.youtube.com/watch?v=Rdr-KZChM00">source</a>