Resources
Q & A
Glossary
Acronym Guide
Further Reading
Outside the Site
Google Sky
WWT
Facebook
Youtube
Vimeo
Twitter
Flickr
Pinterest
Multimedia, Etc
Images/Illustrations
Animation & Video
Special Features
Chandra Podcasts
Chandra Mobile
Desktop Images
The Big Chandra Picture
High Res Prints
Presentations
Handouts
Screen Savers
Audio
Web Shortcuts
Chandra Blog
RSS Feed
Chandra Mobile
Chronicle
Email Newsletter
News & Noteworthy
Image Use Policy
Questions & Answers
Glossary of Terms
Download Guide
Get Adobe Reader
Q&A: Cosmology

Q:
What if there was an event(source)) picked up by Chandra, detected opposite the center of the universe, 20 billion l/y away, and moving toward us, not expanding or moving away. Could we possibly "see" something that did not originate from "our" universe?

A:
This is counterintuitive, but the universe is actually 156 billion light years wide, according to a NASA study of 2 years ago, because of what happens to light when the universe expands (they may have released a revised number more recently but I didn't see a press release about it). Please see:

http://www.space.com/scienceastronomy/mystery_monday_040524.html There is interesting discussion in the section given under "Impossible? Cornish explains further".

To directly address your question, no event or source can move fast enough to overcome the expansion of the universe that is faster than the speed of light.

Back | Index | Next