What is the coolest feature you have seen in a plane? by Ivan Tregear
Answer by Ivan Tregear:
These are the windows on the Boeing 787 Dreamliner.
No shades, no cover, no curtains. Instead you can change how much light they let in. The way it works is amazing too. There is a gel sandwiched between the glass, which can vary its transparency based on the amount of current running through it.
I don’t fly too often, so I’m not sure how common these are nowadays. But I first saw them pretty soon after the Dreamliner was introduced, and as a little kid they blew my mind.