Posted by del.icio.us bot at November 8th, 2008

  • Cloaking a region of space is relatively straightforward but cloaking an object in that space is another matter. Lai and co say the trick is to work out the optical properties of the object and then embed the “complementary image” within the cloaking material. So a plane wave would be bent by the object but then bent back into a plane as it passes through the cloaking material.
    Et voila: cloaking at a distance. And in a way that doesn’t leave the cloaked object blind.

  • We are visible to bots even when we are not at our computers. Next time you are on a downtown street, contemplate the bot-controlled video cameras watching you, or the bots tracking your cellphone and sniffing at your Bluetooth-enabled gizmos. We walk through a gauntlet of bot-controlled sensors every time we step into a public space and the sensors are proliferating.