Does there not have to be a “fixed point” of reference somewhere in the universe in order to measure time? Else, how does one know they actually returned to where they were in time?
To travel back in time, ... it seems all life processes would operate in reverse, cells decayed - restored, energy previously expended recovered to its original state, etc. Therefore, does not the professor have to prove first that there is no 2nd law of thermodynamics for this to work? Also, I would be interested in how the professor’s mathematical solution addresses the condition of temperature = “absolute zero”.
Other than that, I am going to get another cup of coffee and not try to tax my brain too much this early.