Correction: This article has been updated to correct the frequency with which the north and south poles of Earth's magnetic field swap places. (newscientist.com)
If a laser is tuned to the correct frequency, atoms will absorb its light and later re-emit the absorbed energy at a higher frequency. (newscientist.com)
Passing terahertz radiation at the correct frequency and polarization through the array allows extraction of information encoded into the conductivity.» (sciencedaily.com)