Ugh! Billy will never never like me back. My life is horrible!
Kelly, please come over. I would like to explain something to you.
What the heck? But that's really big! I remember that one light year is 5.8 trillion miles!
Scientists don't know exactly how big the universe is because they don't know the shape, but by studying lights in the sky and dating them using special technology, they know that the universe is at least 13.8 billion light years in any direction.
But, Mrs. Brulliam..
Hhmm... I also know that the universe could be infinite!
Kelly, that is only the beginning! According to the Big Bang Theory, the universe is constantly expanding. So, if it has been doing so at a constant rate, the observable universe is actually more like 48 billion light years in any direction.