Ultrafast scanning tunneling microscopy reaches the quantum mechanical space-time limit for the first time‎

Werner Heisenberg's famous uncertainty principle describes one of the most intriguing features of quantum physics: certain pairs of physical quantities describing a particle, such as position and momentum, cannot simultaneously be determined with arbitrary precision—not because of imprecise measuring instruments, but because nature forbids it. Between position and time, however, there is no Heisenberg uncertainty principle.