At the end of Russian Doll series 2 we are told about entropy. The enclosure of time to allow it to flow in one direction. Irreversible processes. One cannot, for example, unfry an egg, neither can Galactic Midnight reverse.
It is an event which is inevitable.
But only if we look at time in a linear fashion. This is the perspective we are designed to use, how our external faculties process incoming data whether visually or auditorily, this direction is fixed.
Hence, we look at different perspectives to ascertain if it is possible, as in Russian Doll to switch time around.
Such ideas have been postulated for years, since the idea of time-travel itself. Since what is known in pop culture as science fiction was created. A genre which investigates such thinking and documents author's thinking on these matters.
Static anchor points in time are created at most levels of energy, from quantum through micro to macro and out to galactic. Primer is a prime example of a consciousness investigating this phenomenon. An anchor in time is used to undulate across wavelengths of space to its counterpoint which in turn allows for closed loop causality. Happening at any level, this is part of the Galactic Midnight hypothesis.
Primer should be seen as a start to time-travel and its relation to wavelet bounce.