Why is it difficult to understand the expansion of the universe?
One of the most frequently asked questions at Ask and Astronomer--and one of the most infamously tough to answer--has to do with the expansion of the universe: what is at the end of the universe? Because if the universe is expanding, it must be expanding into something, right?
No. A number of previous pages (see "related questions") address this question, but I would like to stop for a minute to talk about why it is so tough for us to get our minds around this issue, and why answers that are technically correct can still be unsatisfying.
Trying to understand the expansion of the universe is a bit of a paradox--because really understanding it involves "giving up" on ever comprehending it in the same way that you comprehend your everyday physical world. I might tell you to picture the universe as an expanding raisin-cake or a four dimensional balloon (some favorite mental models), but it just isn't possible to grasp "the universe" in the same intuitive way that you understand, say, the shape of a ball in your hand.
That doesn't mean that it is impossible to understand the expansion of the universe, but it does mean that, for most of us, that understanding will be of a different quality than what we're used to--it will be grounded in mathematics rather than in physical experience.
Get More 'Curious?' with Our New PODCAST:
- Podcast? Subscribe? Tell me about the Ask an Astronomer Podcast
- Subscribe to our Podcast | Listen to our current Episode
- Cool! But I can't now. Send me a quick reminder now for later.
- What is at the end of the Universe?
- What was there before the Big Bang and what is there outside of our universe?
- What is the universe expanding into?
- What is a white hole?
- Is the universe really like an expanding balloon?
How to ask a question:
If you have a follow-up question concerning the above subject, submit it here. If you have a question about another area of astronomy, find the topic you're interested in from the archive on our site menu, or go here for help.Table 'curious.Referrers' doesn't existTable 'curious.Referrers' doesn't exist
This page has been accessed 50099 times since April 29, 2003.
Last modified: May 5, 2003 3:10:02 PM
Ask an Astronomer is hosted by the Astronomy Department at Cornell University and is produced with PHP and MySQL.
Warning: Your browser is misbehaving! This page might look ugly. (Details)