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septembrie 30, 2011
Státic
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septembrie 29, 2011
Par-delà
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septembrie 28, 2011
Contemplatív
Controvérse
septembrie 25, 2011
Innocents Abroad
utterly
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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
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«Cette opération, faite hors de tout cadre juridique, constitue une voie de fait»