The universe might have a fundamental clock that ticks very, very fast

Amazing stuff! What is time? Is the arrow of time only in one direction? Is there a smallest unit of time? Is there a universal clock?

"... If the universe does have a fundamental clock, it must tick faster than a billion trillion trillion times per second, according to a theoretical study published June 19 in Physical Review Letters. ... In particle physics, tiny fundamental particles can attain properties by interactions with other particles or fields. Particles acquire mass, for example, by interacting with the Higgs field ... Perhaps particles could experience time by interacting with a similar type of field, says physicist Martin Bojowald of Penn State [co-author of the paper]. That field could oscillate, with each cycle serving as a regular tick. ..."

"If time is described by a fundamental process rather than a coordinate, it interacts with any physical system that evolves in time. The resulting dynamics is shown here to be consistent provided the fundamental period of the time system is sufficiently small. A strong upper bound TC<10−33s of the fundamental period of time, several orders of magnitude below any direct time measurement, is obtained from bounds on dynamical variations of the period of a system evolving in time."

"... Physics has a time problem: In quantum mechanics, time is universal and absolute, continuously ticking forward as interactions occur between particles. But in general relativity (the theory that describes classical gravity), time is malleable—clocks located at different places in a gravitational field tick at different rates. Theorists developing a quantum theory of gravity must reconcile these two descriptions of time. ..."

The universe might have a fundamental clock that ticks very, very fast | Science News Time could be the result of particles interacting with a ticking cosmic timepiece

The Period of the Universe’s Clock Theorists have determined 10−33 seconds as the upper limit for the period of a universal oscillator, which could help in constructing a quantum theory of gravity.

Here is the link to the underlying research paper (no open access):
Physical Implications of a Fundamental Period of Time