Sean Carroll asks the question: "What would it be like if time passed more quickly, or more slowly?" His answer is interesting.
“The crucial question there was: Compared to what? The idea that “time suddenly moves more quickly for everyone in the world” isn’t operationally meaningful; we measure time by synchronized repetition, and as long as clocks of all sorts (including biological clocks and clocks defined by subatomic processes) remain properly synchronized, there’s no way you could tell that the “rate of time” was in any way different. It’s only if some particular clock speeds up or slows down compared to other clocks that the concept makes any sense.”
This raises the question: what do we really know about biological clocks in terms of time dilation? We are told that the astronauts who have spent the most time in Earth orbit are minuscule fractions of a second younger than they would be if they had remained on Earth; but what does that actually mean?
People who suffer from any of the forms of progeria appear to age more quickly than the vast majority of people. Is this due to their biological clocks running at a different rate? Are their bodies "experiencing" time at a rate that is different from that experienced by their minds? If biological clocks can vary in this way, what evidence do we have to indicate that they will be influenced in the same way as mechanical or atomic clocks by time dilation?
