Originally Posted By: Marchimedes
Originally Posted By: Momos
1) Why should the stars on the inside of your postulated shell be deceleration? It can't be gravitational pull.

I don't have any stars inside the shell, the stars are the shell.

I know, but in your example with the cars, you explain the apparent expansion of the visible universe by galaxies on the "inner surface" of the shell decelerating and stars on the "outward parts" of the shell still accelerating.
The point is: there has to be some force which is causing this velocity difference.
Why are some stars, NOW (Billion of years after the Big Bang) decelerating faster then others?

Originally Posted By: Marchimedes
Originally Posted By: Momos
2) The speed of galaxies is measured by their redshift.
As far as I know the redshift of distant galaxies shows a velocity of much more then lightspeed (several times of c).
Conventional this ist explained as not beeing the real velocity.

It doesn't show light speed as far as I know.

http://books.google.com/books?id=_2GeJxVvyFMC&pg=PA35#v=onepage&q=&f=false , Page 36:

"However, they are often also described in terms of a redshift velocity, which is the recessional velocity whose linear Doppler effect z would give the same value z=Z, as the measured spectral redshift. The confusing aspect of all this is that the redshift velocity can easily become greater than the speed of light."

But I have to admit my lack of knowledge in this area.
The redshift caluclator
http://astronomy.swin.edu.au/~elenc/Calculators/redshift.php?Ho=71&v1=1000&z1=0.001&v2=1000&z2=10 calculates for any value of z a velocity below c.
So I guess you are right.

Nevertheless aren't we measuring distant objects moving away from us with velocities at least up to 1/2 c?

According to your idea we are living in the middle of the shell of an expanding sphere.

Since we can observe distant object in every direction moving away from us with 0.5 c, this leads me to the conclusion the inner part of your shell is standing still, the middle part (including ourselves) is moving with 0.5c, the outer part is faster yet, moving with 1c.
Otherwise you can't explain the difference in velocities.

Furthermore in your hypothesis we should observe a universe with different velocity distributions to each side. Objects at the same distance to the "point of the BigBang" as us should be moving with the same velocity?
So we shouldn't see any movement of them at all?
(apart from movement due to stretching of the "shell" over a larger amount of space).

In any case, I think your idea is scientific, in the sense that your idea is falsifiable. Your hypothesis makes some observable predictions which don't fit the actual observations.

Originally Posted By: Marchimedes
Originally Posted By: Momos
Expanding space will lead to the same observation *in every place* in the universe: all distant objects are moving away, the more distant they are the faster they move away.This explains why it seems like we are the center of universal expansion and yet we don't have to assume we have any special position in the universe.

Your theory at least requires a careful arrangement of acceleration/deceleration and positioning of our place (roughly in the middle of the shell)?

Actually I would say we are closer to the inside or outside edge of the shell as eveidensed byt eh "hole in the universe" measurement that was taken. It's around here somewhere.

I would guess the size of this "hole" is wrong.

Originally Posted By: Marchimedes
Originally Posted By: Momos
In you hypothesis this [background] radiation should be non-existing (moving faster then any other object it would surround the matter-sphere in an expanding light shell moving through the empty pre-existing-space), or it should be anisotrop, coming from the direction of the "Big-Bang-Point"?

400,000 years after the big band my universe shell would have been still expanding. I guess the radiationhad to come from somewhere so it stands to reason that it came from all matter so it could be coming from the opposite side of my universes shell which would be 800,000 years worth of travel away from us at the time of it's beginning to radiate.

A shell of matter sending out radiation, would be clearly visible. We should have a clear anisotropy with most of the background radiation coming from one side of the universe.
Actually at any point X in time (years after the explosion) we should see only the radiation emitted by the parts of your shell in exactly X - light years distance. I would assume we would measure a circle of background radiation (The intersection of your universe-shell and a sphere with a radius of X light years.