Quantum jumps, when an electron absorbs a photon and "jumps" into another state, were regarded as instantaneous. Scientists have for the first time measured the duration of this 'photoelectric effect', first described by Einstein, in the attosecond range, a billionth of a billionth of a second.

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Quantum jumps, when an electron absorbs a photon and "jumps" into another state, were regarded as instantaneous. Scientists have for the first time measured the duration of this 'photoelectric effect', first described by Einstein, in the attosecond range, a billionth of a billionth of a second.