Just because time is relative does not mean time is subjective. Time is a fundamental objective part of reality, and time and distance relativity is probably less weird than you think it is. There …
twin paradox is also the only way I can rationalize the original claim
The fact that there is a maximum amount of relative time that can elapse between any 2 “events” does not rely on the twin paradox in any way. It doesn’t even depend on movement at all since there is gravitational time dilation and the 2 events don’t even need to be “witnessed” for time to have a particular relative duration between the events. Whichever of 2 different inertial frames of reference has the least amount of gravitational time dilation has the faster time flow rate and is closest to the maximum rate.
If a piece of matter had no gravitational time dilation at all (which admittedly is impossible) what would be the time flow rate for the object? For simplicity let’s assume it is not accelerating or even moving at all (except for expansion of universe). How would we know it is not moving? Let’s assume (call it a thought experiment) that the universe has a center and boundaries, and that the distance and direction to the center is not changing. This object would have no time dilation, the maximum time flow rate, and experience the longest possible duration of time across any arbitrary points in time.
The fact that there is a maximum amount of relative time that can elapse between any 2 “events” does not rely on the twin paradox in any way. It doesn’t even depend on movement at all since there is gravitational time dilation and the 2 events don’t even need to be “witnessed” for time to have a particular relative duration between the events. Whichever of 2 different inertial frames of reference has the least amount of gravitational time dilation has the faster time flow rate and is closest to the maximum rate.
If a piece of matter had no gravitational time dilation at all (which admittedly is impossible) what would be the time flow rate for the object? For simplicity let’s assume it is not accelerating or even moving at all (except for expansion of universe). How would we know it is not moving? Let’s assume (call it a thought experiment) that the universe has a center and boundaries, and that the distance and direction to the center is not changing. This object would have no time dilation, the maximum time flow rate, and experience the longest possible duration of time across any arbitrary points in time.