  A thought experiment is described and the probability of a particular type of
results is predicted according to the quantum formalism. Then, the assumption
is made that there exists a particle that travels from the source to one of the
detectors, along a continuous trajectory. A contradiction appears: for agreeing
with the quantum prediction, the particle has to land at once on two space
separated detectors. Therefore, the trajectory of the particle, if it exists,
cannot be continuous.
