A spacetime modulated matematerial can drag light even though there is no physical motion of the medium.
One of the cornerstones of special relativity is the Fresnel drag experiment, in which a moving fluid appears to 'drag' light along with it.
New results show that the medium does not have to move to drag light. Instead a time dependent modulation of the refractive index, moving like a wave through the medium, will drag light along even though there is no physical motion.
P.A. Huidobro, E. Galiffi, S. Gueneau, R.V. Craster, J.B. Pendry, Fresnel drag in space-time modulated metamaterials
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