How To Cloak Objects At a Distance 136
KentuckyFC writes "All invisibility cloaks to date work by hiding an object embedded inside them. Now a group of physicists have worked out how to remotely cloak objects that sit outside a cloaking material. The trick is to make the cloaking material with optical properties that are exactly complementary to the space outside them. Complementary means that the material reverses the effect the space has on a plane wave of light passing through it. To an observer this space would appear to vanish. The scientists say that to cloak an object sitting outside the cloaking material, first measure its optical properties and then embed a "complementary image" of the object within the cloak. So a plane wave is first distorted by the object but then restored to a plane by the complementary image of the object within the cloak (abstract). An observer sees nothing. This method has another benefit. Objects hidden in conventional cloaks are blinded because no light enters the cloaked region. But objects that are remotely cloaked like this should still be able to see their surroundings."
Re:Wow smart scientists... (Score:5, Informative)
Only on /. would someone try to explain such science in terms of bitmasks. :)
Re:How to not be seen at a distance, low-tech styl (Score:5, Informative)
I'd like to see your source on that one, Assuming that sound can't move through the rest of the rifle(for sake of discussion) and will only escape out of the muzzle the shooters ear is about 1 meter away form the source. The Barrett M82 (using .50 BMG round) has a max effective range of 6800m with a muzzle velocity of 853 m/s. That means that it will take that round 7.79 seconds to go the max distance or 2.16 seconds to go the effective range of 1850 meters.
The speed of sound is 340.29m/s, so for the sound of the gun shot to go from the muzzle to the shooters ear 1 meter away will take apx 0.0029 seconds.
At 853 m/s the round will have only traveled 2.47 meters away from the muzzle.
Provided the target is less than 2.47 meters away then yes the will have a whole in them before you the shooter hears teh shot, but you said thousands of yards, which as we proved is just wrong. Now had you said that you the target will have a whole in you before you the target even hears the report then yes you would be right.
Oh and you totally misused the joke anyway of th GP. It was a Monty Python sketch. /All figures from GIS and wikipedia) //Math could be wrong, please correct me if I'm wrong