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.
There is no way to picture the sheer size of our universe, but this visual might help. If the sun was the size of a penny, the nearest star would be 750 miles away. Our galaxy would be 7.5 million miles across!
It's a bit scary, how small we are...
The universe is very old, too. If the age of the known universe was condensed into 24 hours, modern human existence would only be 14 seconds long.
Well, Kelly, the universe is very big and very old, but that doesn't mean we can't make an impact on it. You can only do this, however, if you don't get hung up on small problems, like if Billy likes you, but by tackling big ones. Keep that in mind.
Well, this has been very informative. But, ma'am, may I ask why you told me all of this?