> It's like glass windows getting thicker on the bottom over the centuries. They actually don't. If a glass window is a thicker at the bottom it's just because

> It's like glass windows getting thicker on the bottom over the centuries. They actually don't. If a glass window is a thicker at the bottom it's just because it was considerably more difficult to make them perfectly even in previous centuries and people probably had a slight tendency to install them with the thicker parts on the bottom, but you can find centuries old glass windows that are thicker at the top.