I'm posting this in order to better understand the relationship between the rate at which time passes and an object's velocity. As I currently understand it, as the velocity of an object increases, time, or the rate at which time passes, slows in order to keep the speed of light a constant for that object. So, an object, with mass, moving at a certain velocity will have a certain time rate specific to that object at that velocity. Now my question is two fold. First, what is the rate of time of the earth? I would like to be specific about this. Because, as I understand it, while I feel no motion I am actually moving at an incredible speed through space. For example the earth is spinning, which gives me, on its surface, some velocity. Next, the earth is also traveling around the sun in its orbital path which again gives me added velocity. Also, the solar system is traveling about the galactic center with some velocity, and lastly, the galaxy itself is flying through space with its own velocity. So, I'm wondering, how fast does time move for me in comparison to lets say an area of empty space? Which brings me to the second part of the question. How fast does time move in an area of no mass? For example the area between stars or maybe the area between galaxies. Along this line of reasoning to seems to me that time might move at different rates in different parts of the universe corresponding to objects which have higher or lower velocities. Also, I'd like to know how does time flow when there is no mass around? I'm very curious about this so if someone could please clarify this for me I'd greatly appreciate it.