Stealth drone spins so fast that it disappears

A new drone avoids detection by spinning so fast that it blurs into the background, offering a simple way to evade visual tracking. While it can still be heard, this approach could help military and surveillance operations without relying on complex materials or technology. It’s a clever, low-tech solution to a high-stakes problem.
Stealth bombers use exotic materials to lower their radar signature and spy satellites orbit Earth far outside human sight, but a new drone avoids detection in an altogether simpler way: spinning so fast that it blurs into the background.
New Scientist