  With the theory of special relativity, time has been linked with space into a
four-dimensional space-time from which a basic question must be asked: can
space be really transformed into time and vice-versa? The response is
affirmative if time has the same structural topological structure as space at
the subplanckian quantum level in such a way that a discrete structural quantum
time constitutes the time part of the space-time internal vacuum of every
elementary particle. It has thus been shown that a quantum time, quantized
algebraically according to a lattice of time quanta, really exists and is
emergent in the sense that time quanta can be transformed into space quanta and
vice-versa. Furthermore,this quantum time, only relevant at the subplanckian
scale, is proved to be in one-to-one correspondence with the absolute and
relative clock times.
