 The resulting localisation can be on a very short length scale, i.e. the characteristic length above which coherence is dispersed (‘coherence length’) can be very short. A speck of dust of radius \(a = 10^{-5}\)cm floating in the air will have interference suppressed between spatially localised components with a width of \(10^{-13}\)cm. Even more strikingly, the time scales for this process are often minute. This coherence length is reached after a microsecond of exposure to air, and suppression of interference on a length scale of \(10^{-12}\)cm is achieved already after a  nanosecond.[5] 