"Roger" hit some keys randomly and said:

I was hoping someone could help me with the following question. I am
trying
to understand something of the size of the universe, and I came accross a
quote that said "the universe is expanding in all directions, and that the
'Cosmic Microwave Background' (the remaining heat from the Big Bang, is
found at a distance of 15 billion light years from us in all directions."

Tow questions result from this:
- does this not suggest the universe is ball-shaped, and
- that the earth is pretty much at the centre of the universe, near where
the Big Bang occurred?

Any input you can give me (in laymen's terms, please) would be welcome!

Rogier


I expect Pat or OM to cain me for anything I say here that is not text book
correct, but here is my interpretation from some books and sources i've read
(including steven hawking: universe in a nutshell, and a brief history of
time)

Yes, the universe is expanding in all directions, so in essence it is a
sphere (or sphere like universe) however it gets interesteing because the
universe expands at the speed of light... the CMB radiation is exactly that,
its background... we are by no means the centre of the universe... thats
pretty christian and egocentric :-)

The way ive interpreted it, correct or not, is that with all the energy and
comotion of the 'big bang' its early stages were very non uniformed... I
guess if you compare it to your regular explosion or firework, the immediate
explosion is not round within, lets say 1 ft diameter, but the sparks that
fly out eventually turn into a ball... the rate of expansion evens out but
is still not completely uniform... NASA has some pictures of the CMB
radiation which shows this... i'm sure you've looked...

I guess when it comes to the universe all we can do is rely on a theory
until another one that proves that little bit more comes along, then we
shift our thinking in that direction... its been a while since i've read the
steven hawking books but they are brilliant and well worth borrowing from
your local library or buying on amazon.com... not sure if they are available
as ebooks yet... here's hoping

Hope this helps... now i'll wait and see what the gang have to say hehe :P
Go easy guys!

Niko