Tony Markham wrote:
The answer to your question is that the Big Bang occurred "everywhere" within an incredibly small universe and that universe has expanded to become the universe that we live in today
How have you deduced that the Universe was incredibly small? From which other entity present at this time have you decided to assume 'small' against?
Would you not have been better saying 'incredibly infinite'?
Moving on regarding the skin of the proposed balloon, in assuming that there is a skin in the first place, automatically means you assume our Universe is expanding into some imaginary volumetric receiver and that there is an 'edge' where our Universe ends and where nothingness starts.
Firstly, the cosmos into which we look at night gives the appearance that we are sat in a volumetric sphere - looking at stars as if they surround us nice and neatly. This is not the case, the reason there is a star in the northern sky and one in the southern sky may not be because they are in opposite directions geometrically from the Earth, in fact they may be both in the same horizontal and vertical planes.
This is the easiest way I can explain to people:-
Imagine you are stood in front of a wall which is 20 feet in front of you, you see that the wall stretches 20 miles left, 20 miles right, 20 miles up and 20 miles down. The wall is pitch black but light bulbs have been placed along the wall everywhere.
This gives you a dimentional feeling when you look at the most distant bulbs.
Now imagine that this wall, instead of being 20 miles in each direction is billions of light years in every direction except with a slight twist to the equasion - the wall is warped a little. Because the wall is warped, objects you would normally see either left, right, up or down now appear behind you. Visually, the warped wall is wrapped around you as if you were sat in the middle but mathematically it is as flat as a pancake.
The Universe is mathematically flat but appears spherical. When you understand this, images of balloons will disappear out of your head and a new image will appear. The new image asks 'is the flat mathematical Universe warped concave or convex in accordance to Earths location'?
The answer to that is of course neither, because the wall is still flat. It just doesn't appear that way to our misunderstanding minds.