Unfortunately, no one has followed a balloon up to see what really happens up there as far as I know. And on top of that, you have to keep adding air without tying a knot to over-inflate a balloon ...

The balloon weighed over 5,000 pounds ... causing the pieces to stick together and tear once the balloon was fully inflated. By 1935, engineers had made significant developments for Explorer ...

Hold your balloon up to a light so you can see where the skewer is inside. When you inflate a balloon, nearly all the rubber stretches... a lot! As the rubber stretches, it gets a lot thinner too.