Is the universe round and if so how large is it and what is on the outside ?

Answer 1

According to current theory, the universe can have one of three basic shapes: sphere, flat, and saddle. Many astophysicists today subscribe to the flat model. But there is no universal consensus (pun intended).

Einstein incorporated a more or less arbitrary constant in his theory of relativity equations to make things come out right. For Einstein, that meant a stable, non contracting or expanding universe. That constant is called the cosmological constant. Check this out:

"The cosmological constant (usually denoted by the Greek capital letter lambda: Λ) was proposed by Albert Einstein as part of his theory of general relativity to achieve a stationary universe. After the discovery of Hubble redshift and the introduction of the expanding space paradigm Einstein abandoned the concept. New discoveries in the 1990s have, however, renewed interest in a cosmological constant." [See source 1.]

Among these "new discoveries" was the observation by Hubble (and others) that the universe is not stable...it is expanding and accelerating. The value of the constant, normalized around zero value, dictates the shape of the universe. Check this:

"There are three categories for the possible spatial geometries of constant curvature, depending on the sign of the curvature. If the curvature is exactly zero, then the local geometry is flat; if it is positive, then the local geometry is spherical, and if it is negative than the local geometry is hyperbolic." [See source 2.]

When the constant > 0, the universe shape is closed (spherical); when it is < 0, the shape is hyperbolic (saddle); when it is zero, the shape is flat. Current speculation puts the constant at nearly zero; so the speculation is that the universe is nearly flat.

This is a good thing because if the universe were not flat, the Pythagorian equation c = sqrt(a^2 + b^2) would not work in 3D space at great distances.

As to the size of the universe, the big bang happened about 13 billion years ago. Light has been traveling about that long; so it has traveled about 13 billion light years. Thus, the observable universe is about six trillion miles per light year X 13 billion light years = 78 trillion billion miles in diameter and getting bigger every day. What lies outside our observable universe is anyone's guess.

Answer 2

The universe is constantly expanding in all directions at the speed of light because all the galaxies are travelling away from each other. Take into account that this has been going on since the Big Bang and you realise that the Universe is indeed pretty big. On the outside will be the stars moving fastest. These are most likely to be quasars (spinning stars) which have the most energy and are travelling at the speed of light. It is impossible to tell for certain what is on the outside of the Universe, simply because we could never see it.

Answer 3

No one actually knows how vast the universe is.
The Big Bang theory states that the universe is constantly expanding at a gradual rate until it reaches it's limit.
The Big Crunch theory states that when the universe reaches its size limit, it will then gradually shrink back into a subatomic particle (smaller than an atom).

Answer 4

Well basically the universe is an ever expanding sphere. So that I don't bore with the techincalities, imagine you are inside a football(Soccer ball)and you cover the inside of this ball with the universe. You then turn it inside out. Then you have a sphere in infinite space for it to expand :-)

Answer 5

I don't think It's round, rather growing like smoke, there is no outside, Our minds are too small to comprehend that time and space are not constant, only the speed of light is

Answer 6

No one knows, but it it theorized that it is a donut shape, and is constantly getting bigger. Once the energy expanding the universe runs out, however, the universe will shink and tim will go backwards untill the beggining of time. This will keep repeating itself forever.

Answer 7

ive asked this question many times and the truth is nobody know but i have tried to answer it myself and have put it inot my blog

http://blog.myspace.com/tristram_lesslie

if you open the link and keep scrolling down till you get to the heading "the universe and everything" i try to give a good answer to all the questions people ask on here though it is long it has some very good points in it

Answer 8

There's nothing outside the universe. That's the whole point to the curved space theory......I think.

Answer 9

The visible universe is a sphere approximately 13.5 billion light years in radius. It doesn't have an "outside" or an "inside".

Answer 10

what proves that the universe is round?