First-rate engineering
http://www.veluxusa.com/products/roof-windows
https://www.westsidewholesale.com/velux-gdl-pk19-3066.html?gclid=CjwKCAiAr_TQBRB5EiwAC_QCqzUG0a9eUvcdv-N9MmI3yU3Zny1QOIieLbgf6ftWpTKhJcYZzYukJRoCkK4QAvD_BwE) They’re $3,400
Source
I read a comment that piqued my interest and have been trying to find some deeper info on the subject. The comment basically said that as the universe expands, something on the Planck level is dividing like cells, producing more space. I’m not asking for an explanation of that concept, but rather wondering precisely what is happening on that scale when space expands.