Universe expansion....?

Question

From most of the explenations I've found and recieved. Its like a balloon that retains the same mass but stretches thinner. Wouldnt it eventuallly be too thin? and "Bust"?

Answer 1

Yes and then what? its nothing out there but space...Stars and Heaven , it is said that Heaven is about 10000000000000000000000000000000000 to the secon power miles away...

Answer 2

First, remember that the observable universe is considerably smaller than the estimated actual size of the universe. The Universe is made up of a lot of nothing, there is no underlying substance to be thinning. There is nothing to bust. What we call space-time is merely a mathematical set of coordinates that are used to describe a point in four (or more) dimensional space. This includes things like curvature due to gravity. Instead of a violent death, the universe will die in a big freeze, when distances become too great, and all usable nuclear fuel becomes exhausted. This ending follows the laws of thermal-dynamics Modern cosmological theory implies the existence of an anti-gravitational force or universal constant. While discounted in the past as a quick fix to general relativity, the spacing and grouping of the galaxies in the observable universe points to a force acting against gravity and accelerating the expansion of matter. This force is too strong to be overcome by gravity as distances increase, hence the universe will expand forever.

Answer 3

Hmmm...the balloon model is only 2 dimensional, with the surface of the balloon representing the whole of the three dimensions of space. Tape some paper galaxies to the surface of the balloon. They all move further apart from one another as measured along the surface of the balloon, with further ones retreating faster. Plus, there is no center. The expansion is uniform wherever you are. (The center of the balloon is out of bounds. In a 2D universe you are stuck on the surface).

The rubber can stretch infintesimally; there is no elasticity fighting the expansion. You have taken the balloon metaphor too far when you think about that possibility. The real universe is 3D expanding in a fourth dimension (I suppose you could think of the radial direction of the balloon's expansion as time.)

The only thing that is 'thinning' is the average density of matter and energy in the universe. I dunno, maybe at some point electricity and magnetism decouple and space will go through another "symmetry breaking phase transition" like when the strong force decoupled from the electro-weak.

Answer 4

No, do not think of the Universe that way. The Universe has 3 possibilities. The 1st one is that the Universe will keep on expanding forever. The 2nd one is that the gravitational forces within our galaxy will stop the expansion and the Universe would become static. The 3rd one is that the gravitational forces within our Universe will cause the Universe to stop expanding and then will make it contract into a "big crunch".

Answer 5

I think you're missing the point. The universe is getting thinner, not the thing containing it. As far as we know there is nothing containing it. If this theory is correct the universe would not burst but would eventually become thin enought that things would have to move to make room for each other. Eventually the universe would become too thin to house all of its contents.

Answer 6

Okay, this is what I can't figure out (and I apologize in advance for answering a question with another question) but:
If they have PROVEN that the universe is expanding....doesn't that mean that the universe has boundaries and is not infinite as everyone is trying to make it out to be? I have heard the balloon theory but it doesn't seem plausible to me...I mean, I'm no rocket scientist, but wouldn't that disrupt the nature of everything INSIDE the universe?

Answer 7

the universe started as a "big bang", a enormous amout of mass in a very tiny space. ths mass exploded and went into every direction. Scientists have proven that certain stars and galaxies are moving closer together, but little by little. there may be a "big crunch" effect, bringing the universe impossibly close together, but this is millions or years away

Answer 8

The evidence for an accelerating expansion comes from observations of the brightness of distant supernovae. We observe the redshift of a supernova which tells us by what the factor the Universe has expanded since the supernova exploded. This factor is (1+z), where z is the redshift. But in order to determine the expected brightness of the supernova, we need to know its distance now. If the expansion of the Universe is accelerating due to a cosmological constant, then the expansion was slower in the past, and thus the time required to expand by a given factor is longer, and the distance NOW is larger. But if the expansion is decelerating, it was faster in the past and the distance NOW is smaller. Thus for an accelerating expansion the supernovae at high redshifts will appear to be fainter than they would for a decelerating expansion because their current distances are larger. Note that these distances are all proportional to the age of the Universe [or 1/Ho], but this dependence cancels out when the brightness of a nearby supernova at z close to 0.1 is compared to a distant supernova with z close to 1.
For: http://www.astro.ucla.edu/~wright/cosmology_faq.html
Until well into this century, it was not understood whether the great groupings of stars that were seen through telescopes were part of our own galaxy, or distant galaxies in their own right. This puzzle was finally resolved by using Cepheid variables to establish a distance to the objects like the "spiral nebula" in the constellation Andromeda, and to determine the size of our own galaxy. By around 1925, Hubble, Leavitt, Hertsprung, Shapley, and others had established conclusively that objects like the Andromeda "Nebula" were in fact much further away than objects in our own galaxy and thus were themselves galaxies.

The Expansion of the Universe
Then, in the late 1920's, Hubble, building on results obtained earlier by Slipher, combined Doppler shift measurements of radial velocities with distance measurements to conclude that almost all galaxies were flying away from the Milky Way, and that the velocity of recession was proportional to the distance from us: the further the galaxy from us, the faster it was receding.
It later turned out that there were systematic errors in the earliest measurements, associated primarily with a failure to realize that there were two kinds of Cepheids, failure to disguish in some cases Cepheid and RR-Lyra variables, and failure to account for the scattering of starlight by interstellar dust. However, although corrections for these mistakes changed the distance scales by as much as factors of two, they did not alter the fundamental conclusions:

There are many galaxies outside of our own.
These galaxies are all receding from us if we go to large enough distances.
The velocity of recession is proportional to the distance from us.
from http://csep10.phys.utk.edu/astr162/lect/cosmology/expansion.html

Answer 9

I've read two theories: Open Universe and Closed Universe. Open Universe says that everything is unlimited. Everything expands to its heart's content (basicly, there is no baloon to burst) Closed Universe states that at some point expansion stops due to all the galaxies and whatnot pulling on eachother, and the universe will start to draw in on itself (the self-contained universe).

Answer 10

Overall mass is retained. I believe the expansion theory just has systems moving away from a central point.