Long bottle-necks. The shape of a beer or a soda bottle is so familiar, nobody would think twice about it. But it turns out this long bottleneck is shaped this way on purpose.According to “Interesting Engineering,” such a design allows packers to seal off the top with a small bottle cap, reducing the size of the seal and thus saving money. Plus, it’s practical, since a small seal on a beverage container is stronger and more reliable than one which covers a larger area.