Backward bending light key to stealth

From 'ABC Science'

Scientists have for the first time demonstrated a reversal of the optical Doppler effect, an advance that could lead to the development of 'invisibility cloak' technology.

The Doppler effect describes the change in frequency of waves whenever there is a relative movement between an observer and a wave's source.

"This is the first time that the inverse Doppler effect has been demonstrated in the optical region," says Professor Min Gu, Director of Swinburne's Centre for Micro-Photonics.

Link to full article

Soon the FEDS will be parked outside and you won't even know it.
I can't help but worry that if stealth technology became effective and affordable, it would be used for intrusively monitoring citizens.

but on the other hand if us citizens ever got ahold of steath tech ....area 51 would be open to the public