unique identifier

A piece of paper runs through the printer of this machine in an endless loop. Each time a person stands in front of the machine, the current UNIX time is printed on the paper. As the paper runs through the printer again and again, it is possible that individual time stamps are overprinted and thus become unrecognizable. Here the notion of the uniqueness of each moment in a linear time is set in relation to the notion of a periodic time.
UNIX time is the standardized, internal representation of time in computers. It counts the seconds (or smaller units) since 01.01.1970.