Go Back   Steam Users' Forums > Steam Discussions > Off Topic

Reply
 
Thread Tools Display Modes
Old 08-05-2012, 02:22 PM   #1
josephdinatale
 
Join Date: Aug 2008
Reputation: 545
Posts: 102
Physics brahs: I have a question about the universe expanding.

If the universe is expanding, then what is it expanding into?

Here's a picture I made to illustrate my point:

http://i3.photobucket.com/albums/y89...Untitled-3.png

A finite universe expanding doesn't make sense.


To me, it would only make sense if the universe was infinite. Let's say the universe was the set of numbers {1, 2, 3, ...}. This is an infinite set of numbers. Well let's "expand" the universe by adding the number 2.5. Well the set is still infinite. Therefore it can expand but still be infinite. Therefore the is no "outside" the universe.
josephdinatale is offline  
Reply With Quote
Old 08-05-2012, 02:24 PM   #2
arisaka
 
 
 
Join Date: May 2009
Reputation: 398
Posts: 1,435
I always thought that everything inside the universe is expanding.
arisaka is offline   Reply With Quote
Old 08-05-2012, 02:25 PM   #3
Porcupeth
 
 
 
Join Date: Dec 2011
Reputation: 2147
Posts: 1,868
Quote:
Originally Posted by josephdinatale View Post
If the universe is expanding, then what is it expanding into?
the next big bang
Porcupeth is offline   Reply With Quote
Old 08-05-2012, 02:26 PM   #4
sdaniels7114
 
Join Date: Oct 2007
Reputation: 2421
Posts: 71
I think its because its not expanding the way an empty balloon expands; but then again I just barely got past F=MA. So don't take my word for it.
sdaniels7114 is offline   Reply With Quote
Old 08-05-2012, 02:32 PM   #5
Mr.Ceefus
 
 
 
Join Date: Feb 2010
Reputation: 1735
Posts: 827
Some believe it will expand to a certain point and then collapse back in on itself becoming a singularity again. I have no friggin idea either way.
Mr.Ceefus is offline   Reply With Quote
Old 08-05-2012, 02:34 PM   #6
Modiga-Disabled
 
Modiga-Disabled's Avatar
 
Volunteer Moderator
Join Date: Nov 2004
Reputation: 10254
Posts: 10,008
Imagine a balloon. Now imagine the Universe as we know it is the surface of that balloon. Imagine the balloon is then inflated. The surface of the balloon is thus expanding. What is it expanding into? The air around. Imagine trying to travel in the direction of expansion while being constricted to the balloon's surface.

And there you have it, a simple model that is almost entirely but not quite unlike how the Universe works.

__________________
Need something? PM me or contact support
Modiga-Disabled is offline   Reply With Quote
Old 08-05-2012, 02:35 PM   #7
Master Splinter
 
Join Date: Jul 2012
Reputation: 1584
Posts: 93
That's one of the most intriguing question in the current physics paradigm: What's beyond our Universe? And no matter how much anyone on these forums think they know about physics, no one will be able to truthfully answer that question.

There are many theories: Some say that our Universe is just an "hologram" formed from the information of other parallel dimensions called "branes", and that, whatever it is, is what lies beyond our Universe.
Others suggest our Universe is just one of many, and that the Big Bang was a result of a collision with another Universe. The analogy is that our Universe(s) are akin to the bubbles formed when you boil water, and that Universe(s) come and go; what lies beyond that? just the "water"...
Master Splinter is offline   Reply With Quote
Old 08-05-2012, 02:37 PM   #8
IcarusNine
 
Join Date: Jun 2005
Reputation: 5600
Posts: 2,571
Quote:
Originally Posted by josephdinatale View Post
Let's say the universe was the set of numbers {1, 2, 3, ...}.
A. Your analogy is terrible.
B. There isn't really a difference between the expansion of a finite universe and the expansion of an infinite universe for how easy it is to comprehend.
C. Your analogy really is terrible.
IcarusNine is offline   Reply With Quote
Old 08-05-2012, 02:43 PM   #9
Smertnik
 
 
 
Join Date: Oct 2007
Reputation: 1709
Posts: 4,012
I think there comes a point in physics when you can't use familiar analogies anymore, both in micro- and macrocosmos.
Smertnik is offline   Reply With Quote
Old 08-05-2012, 02:50 PM   #10
trojanrabbit.gg
 
 
 
Join Date: Mar 2010
Reputation: 6097
Posts: 1,645
This should help clear up a few of the finer points...
trojanrabbit.gg is offline   Reply With Quote
Old 08-05-2012, 02:53 PM   #11
marie pavie
 
Join Date: Jan 2005
Reputation: 25253
Posts: 10,255
Quote:
Originally Posted by josephdinatale View Post
If the universe is expanding, then what is it expanding into?
Ein Sof.

or
This romance novella will help to explain it

Last edited by marie pavie: 08-05-2012 at 02:58 PM.
marie pavie is offline   Reply With Quote
Old 08-05-2012, 02:57 PM   #12
Chris C177
 
 
 
Join Date: Apr 2009
Reputation: 156
Posts: 846
It's expanding into nothing, as far as I understand it. Literally nothing.
Chris C177 is offline   Reply With Quote
Old 08-05-2012, 03:06 PM   #13
CouncillorDayv
 
 
 
Join Date: Jul 2012
Reputation: 8
Posts: 13
There's a perfect way to explain expansion - the best way is visually, but I forgot the vid I first saw this on, so this is a little exercise.
Open an image editing program and im the middle of the page, draw a few black splodges. These are your stars. Make that a selection and expand it by 10% - everything gets bigger. Now if you take the expanded section and move it around a bit, try to line up the new, big stars with the old small ones. Line up their centers and you'll see that, the universe is expanding AWAY from that star. Move to a different star, and the universe appears to be expanding away from THAT star now. The universe doesn't really expand from a point, more it's just getting bigger, pulling itself out.
Galaxies don't fly away from the center of the universe. It just GROWS. All physical matter is contained within Universe. The Universe is everything. There is a finite amount of matter (matter = energy = can not be created from scratch) and, at the Big Bang, this was all compressed into a veeeeeery very very very small space. Now it's the same matter, but in a more open space, and it forms stars and planets and even life.

Dunno if that was good enough, but hot damn I love astrophysics.
CouncillorDayv is offline   Reply With Quote
Old 08-05-2012, 04:46 PM   #14
ZoSo15
 
Join Date: Nov 2007
Reputation: 568
Posts: 1,673
Modiga's example is perfect. The things is, in order for us to comprehend the expansion of the universe we have to "cheat" and imagine the 3-dimensional universe as a 2-dimensional surface. As 3-dimensional beings we are incapable of comprehending what the universe is expanding into because it's outside our realm.

Pretty interesting stuff. If you still have trouble understanding then smoke a bowl and try again. lol
ZoSo15 is offline   Reply With Quote
Old 08-05-2012, 05:11 PM   #15
Larry1212
 
 
 
Join Date: Apr 2009
Reputation: 2616
Posts: 3,597
http://discovermagazine.com/2009/oct...ighboring-one/
































*Pretends to have read article*
Larry1212 is offline   Reply With Quote
Reply

Go Back   Steam Users' Forums > Steam Discussions > Off Topic


Thread Tools
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is Off
HTML code is Off



All times are GMT -7. The time now is 07:17 AM.


Powered by vBulletin® Version 3.8.7
Copyright ©2000 - 2014, vBulletin Solutions, Inc.
Site Content Copyright Valve Corporation 1998-2014, All Rights Reserved.