UCSB Science Line
Sponge Spicules Nerve Cells Galaxy Abalone Shell Nickel Succinate X-ray Lens Lupine
UCSB Science Line
Home
How it Works
Ask a Question
Search Topics
Webcasts
Our Scientists
Science Links
Contact Information
Why the universe has not end and why is it too big?
Question Date: 2015-04-04
Answer 1:

To be honest, we don't really know what the shape of the universe is - that's because we can't see all of it! You may know that our universe hasn't existed forever; in fact, our universe is about fourteen billion years old (we don't really know what happened "before" fourteen billion years ago, or if it even makes sense to talk about what happened "before", but physicists have a few different ideas for what might have been). But remember that light travels at a finite speed. That means that in the fourteen billion years since the universe was born, light has only been able to travel fourteen billion light years. So when we point our telescopes into the night sky, the very farthest things we're able to see are fourteen billion light years away. That's why we say that the size of our "observable universe" (that means the universe we're able to observe) is fourteen billion light years.

Now, there's more to the universe than just our observable universe, but we don't know what it's like because we can't see it! But in short, that's why the universe has no end - it keeps going and going, but we can't know anything about it farther out that fourteen billion light years because light from anything further away hasn't had the time to reach us.



Click Here to return to the search form.

University of California, Santa Barbara Materials Research Laboratory National Science Foundation
This program is co-sponsored by the National Science Foundation and UCSB School-University Partnerships
Copyright © 2017 The Regents of the University of California,
All Rights Reserved.
UCSB Terms of Use