Hey, I am by no means a physics expert so don't get on my for being somewhat uneducated in the topics of relativity but I have been trying to figure out many seemingly mind boggling questions lately and I was hoping some of you could help. First of all, as it is commonly stated that time progresses slower as a body's speed increases what is it that determines the progression of time. For instance,if the Earth were to increase its rotational speed (only around its rotational axis) would the people living on Earth experience slower aging than if the Earth had not speed up? Why or Why not? What about if the Earth were to increase the speed at which it rotated the sun? Would the increase in speed cause all things on Earth age slower relative to how fast they would age if it had never increased in speed? Secondly, since it is supposedly proven that the Earth is gradually slowing (even if by a few milliseconds per year) does that mean all things on Earth are actually aging faster relative to our ancestors millenia ago? All help is appreciated, I have a few more questions bouncing around but it'll take some time for me to formulate them correctly. Thanks a bunch!