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 . &#xFE0E; Link: https://www.techspot.com/news/113173-researchers-create-drone-becomes-almost-invisible-spinning-25.html