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.