(3 videos / 20 min)
The universe is 13.7 bln years old, however in every direction we look we see objects 47 bln light years away, that is, light should have needed 47 bln years to reach us. So you might ask how could light travel 47 bln light years in just 13.7 bln years? Well this is just a consequence of the expansion of the universe: Light gets dragged away from us.