The Smudge Drone

[They did say it’s hard to see, not hard to hear.]
HOW WOULD ANYONE EVER BE ABLE TO TELL THAT THIS DRONE IS THERE?1

Footnotes:

Be sure to have your speakers on when watching the linked video. That video is also archived here. ↩︎

Link: https://www.techspot.com/news/113173-researchers-create-drone-becomes-almost-invisible-spinning-25.html