septembrie 30, 2011
Státic
septembrie 29, 2011
Par-delà
septembrie 28, 2011
Contemplatív
Controvérse
septembrie 25, 2011
Innocents Abroad
utterly
septembrie 22, 2011
disheartened
septembrie 04, 2011
Time Cloaking
They've even designed illusion cloaks that can make one object look like another.
Time cloaking is possible because of a kind of duality between space and time in electromagnetic theory. In particular, the diffraction of a beam of light in space is mathematically equivalent to the temporal propagation of light through a dispersive medium. In other words, diffraction and dispersion are symmetric in spacetime. That immediately leads to an interesting idea. Just as its easy to make a lens that focuses light in space using diffraction, so it is possible to use dispersion to make a lens that focuses in time. Such a time-lens can be made using an electro-optic modulator, for example, and has a variety of familiar properties. "This time-lens can, for example, magnify or compress in time,"
septembrie 01, 2011
à l'égard
«Cette opération, faite hors de tout cadre juridique, constitue une voie de fait»