Just How Big Is The Universe?

I have quite a fair knowledge of the universe and our standing in it.  I have grasped the idea of its expanse, but I know that I cannot fully comprehend just how large that is.

It is very rare I have to go into detail about anything because usually there isn’t anyone around me that shares my interest in this subject, but on February the 21^st a little miracle happened.  Whilst we were driving back home my partner turned to me.  She wanted to know what the big bright star was that was to the bottom right of the moon.  She suggested that it was the North Star but I had told her that I was sure it was a planet.  As it got darker another star appeared to the top right of the bright star.  This was a reddish colour and it had begun to perk her interests.

Later on I looked into it for us and it turned out to be Venus and Mars.  My partner was astonished that she could not only see them but that she didn’t realise they were so close.  I began to explain to her that they were not close at all and in fact for us to travel there would take quite a while.

She then asked another question, she wanted to know how close the nearest star was to us.  I looked it up and it was roughly around 4.25 light years away.  Her obvious reaction was to try and work that out into something more fathomable based on our terms.  It equated to over 160 trillion miles – she was blown away.

I then tried to put something together for her hypothetically for her to try and understand how vast the universe is.

This is what I explained to her:

The universe does not work on our theory of time, it just exists and we try to interpret it into something understandable and useful.  Imagine if we had the technology right now to travel billions of light years from earth and then look back.  Imagine that we had a super powerful telescope so we could zoom right in on the planet. What would we see?  If we timed it right, we would be able to see the dinosaurs walking around!  We would be able to look back in time and see the planet in a much earlier state.  This is because of the distance we are away from the earth.  If we were 1 billion light years from earth and the planet were to explode, we would not see it for 1 billion years.

It really is hard to comprehend when you’re working with an expanse as vast as the universe.