A so-called 'invisibility cloak' succeeded in making a centimeter-scale cylinder perfectly invisible to microwaves -- from one direction, reported the BBC.
"It's like the card people in Alice in Wonderland," said Professor David Smith of Duke University, who co-authored the study published in Nature Materials. "If they turn on their sides you can't see them but they're obviously visible if you look from the other direction."
The effort to make an object invisible to microwaves began in 2006, but all 'cloaks' have failed to achieve perfect invisibility until now. The invisibility cloak would be difficult to do at optical wavelengths, but microwaves are key in fields such as telecommunications and radar.
[Image: "Stock Photo: Invisible Man" on Shutterstock]