afaict, "time" is simply a measure of matter in motion... ie resonant frequency or how long it takes a liquid to flow x distance. Thus, time is just a mental construct, not a "dimension", and "time travel" is not possible. There is only "now".
Unless all "times" exist at every "moment" and we are merely switching consciousness between those. Maybe we are not even switching, because by "going backwards" we would be losing memories and would not know, that we went backwards. Same goes for forwards. It only seems forward, because our memories change that way. Maybe we are all just coping, trying to make any sense of every state, future, past, present, existin…
My DMT “time loop” experience makes this whole topic extremely fascinating to me. I very clearly (to me, within my own subjective experience) witnessed some of the exact same events happen multiple times (within the timeframe of the experience, anyway). It was like there were two separate chronologies existing simultaneously - that of my subjective experience (the “observer”, if you will) and that of the perception of my reality.