One of my favorite science fiction ideas is in a short story
called Light of Other Days about something called “slow glass.”
Light took decades to pass through. In this story, the idea was
that people could buy glass windows that took so long for the
light to pass through, that they could nostalgically watch long
gone scenes, such as their children playing outside as toddlers
long after they had gone off to college, or green fields with
horses where now ugly cities grew. It was about the speed of
light. Here is a concept that is similar. Instead of slow
windows, it is slow walls. RavenBrick has made a nanotech wall
that can slow down the day’s heat coming into a building. Using
phase-changing material at the molecular level, you get to
transfer the warmth of the sun’s heat from the afternoon well
into the night. RavenBrick makes several clean tech materials
for building that greatly reduce energy needs, most notably
windows that turn off the sun, like Sage Electrochromics windows
do. The one that is new to me