Hi Everyone

I have been watching lots of Space Documentaries as
lately and people still can't seem to work out what the
centre of the Universe is so I got thinking maybe it isn't
something you can see maybe it is Dark Energy that is
the centre of the universe because it is pushing galaxies
further and further apart which suggests its expanding
and speeding up. I know nothing about physics but I
think for that kind force to work best I think it would
have to be at the centre where its influence would be at
its best like the sun for example it is the centre of our
Solar System and our Sun(and all other objects in the
Milky way Galaxy)orbits the Super massive Blackhole at
the centre but no one can find what (apart from satellite
Galaxies) The Milky way orbits. Maybe there is nothing at
the centre but this so called Dark energy.

This however is only a theory and it is probably 99.9%
not what it is at all but I think it might be.

Well Bye for now
Karl
oh and by the Way if anyone has seen the Wonders of
the Universe series with professor Brian Cox I have
heard that the soundtrack can be downloaded via itunes
and on Audio CD it has fantastic music on it and the
Documentary is also available on Blu Ray or DVD

Haha

Welcome!

Well the universe as we know it is theoreticaly composed by Dark Energy (Most of it, about 3/4) Dark Matter (about 1/5) and the matter as we know it (about 1/10).
The theory is, that when the Dark Energy finish turning into the matter as we know, the universe will start to contract and going Big Bang(?).
But again, theories are theories and we will never know. Most of the theories 100 years ago are now obsolete by the actual theories.

We can't be sure about the universe, but we can be sure we will never be sure about it.

If you limit your self to the VISIBLE universe, then we are, indeed, at the center.  But we are probably on the edge of someone ELSE'S visible universe.

Ladies and Gentlemen, we are all inside a marble. Haven't you all seen Men in Black? They wouldn't lie... would they?

It's a good theory Karl, but not quite on the nose

There's a common misconception (which you have
avoided) that says that the expansion of the universe
is caused by dark matter; it is actually not explained
by dark matter at all, but dark energy.

Now, the crazy thing about dark energy is that we
have no idea what it is. For all of our observations,
we don't really even have any proof that it
exists. It is formless, massless, and in pretty much all
other ways invisible. What dark energy really is, is not
an energy at all; it is a cosmological constant. Dark
energy is just a pretty name to explain the completely
unexplainable phenomenon of an increasingly
expanding universe.

Dark energy is really poorly named; it isn't localized -
indeed, it isn't physical in any way. It can't interact
with normal energy and as far as we know, is
massless (though still energetic, though not in a way
dark matter or light matter are), etc.

Sorry about the long-winded explanation! I love
cosmology... hoping to get in to grad school to
continue studying it in depth

And Teran's right; there's really no way for us to tell
where the center of the universe is. Space is
expanding much faster than the speed of light
outside the edge of our observable universe, so the
light from those areas will never, ever reach Earth
(unless the universe stops expanding). Because of
the complexities of doppler shift (and doppler's law),
it actually appears that we are the center of the
universe, since almost everything appears to be
moving away from us.

Ah this stuff's so interesting... Sorry if that post was
too long

Thanks for the comments guys

The big question i think is: is there a center to the universe at all? (if you can discount the expansion, say you could take a snapshot of the universe at one moment in time) If the universe is infinite, then there is no real 'center.' There are even theories that say the universe is like a loop and if you keep going one way, you'll eventually end up where you started!

On a side note: have you ever heard of a fellow named Mordecai Milgrom? he came up with an theory called MOND (Modified Newtonian Dynamics) that said Newton's original equations about gravity were slightly wrong. Basically all he did to change them was rewrite the equations so slightly that Newton would never have noticed it (the changes only show effects at extreme conditions that Newton would never have seen), and all of a sudden everything worked - there was no need for dark matter or dark energy to explain the expansion of the universe or the extra speed of galaxies rotation. Really interesting idea IMO, but i never heard much else about it, i suppose it was a little too 'fringe' for the mainstream 

Edit: found Mond on wikipedia, also found another theory based on it, called TeVeS - interesting stuff if you haven't read it!

Also found this interesting thread where people argue over which make more sense, Mond or dark matter/energy Definitely no clear cut winner in this battle yet!

Great thread. I don't really have anything smart to add so I'll just leave it at that... Great thread.

I have read that scientist maybe never will be able to discover the center of the universe because of the huge gravitational forces of black holes that distorts light.

Another interesting fact that maybe there is no center at all. "The Big Bang should not be visualised as an ordinary explosion. The universe is not expanding out from a center into space; rather, the whole universe is expanding and it is doing so equally at all places, as far as scientists can tell. The Big Bang was not an ordinary explosion at all. It was an explosion of space, not an explosion in space. According to the standard models there was no space and time before the Big Bang. There was not even a "before" to speak of. So, the Big Bang was very different from any explosion we are accustomed to and it does not need to have a central point.

If we see a galaxy B receding from us at 10,000 km/s, an alien in galaxy B will see our galaxy A receding from it at 10,000 km/s in the opposite direction. Another galaxy C twice as far away in the same direction as B will be seen by us as receding at 20,000 km/s. The alien will see it receding at 10,000 km/s:"

Here is the map of the observable universe within 13 billion light years radius and there is no center and no end at all


Here is more larger version of the map with some details.

This is absolutely shocking how huge the universe is and the more frightening thing is that we dont even know how much we discovered from it. Maybe less than 1%

Thank you for this great map.

I think that this map gives the false impression that the
Virgo cluster – which includes the Local Group with our
galaxy inside – would form the center of the universe.

It's like on earth: No matter where you are now –
anywhere you stand it’s the "center" of the earth, for a
spherical surface has no definable center.

If we extend this picture to one dimension more, it is
clear that the universe may have no center, because it is
a "three-dimensional spherical surface" (even if we
humans can not imagine this mentally).

About the helpless attempts by modern cosmologists, to
explain our world "in a final way" I just laugh. Imagine
that followers of alternative world views (often being
ridiculed by „serious“ scientists) have created such a
term as "dark energy"- the indignation among
conventional scientists would be huge. Now these
conventional scientists use even such mystical concepts
such as "dark energy " or "dark matter " (sounds like a
Satanic fair or an black metal gig, isn’t it?) by themselfs.
Because they can not admit that they are at their wits'
end.

When I was a child „Big Bang“ was just one theory
among others. Today is the only way which is allowed to
think. Our modern world is full of prohibitions to think
something specific which is outside the common
scientific thinking. The middle age is still alive :-(