Hello All, I am new here and I have been searching for answers to some questions I have. Please excuse me if what I am asking has previously been answered here, I did try to search but didn't have much luck. If you can direct me to the thread where it has been previously discussed then that would be great. Alright, here goes. As I understand it gravity affects the rate of time flow. For example, time of an atomic clock located on the surface of Earth would run slower than an identical atomic clock located on a satellite orbiting Earth. I believe this is a real-world problem that had to be solved for the GPS system to work correctly. Given this information I would have the following questions: 1. If two identical twins were available for an experiment and one stayed on the surface of Earth while the other lived on the international space station (or even in a shuttle) for a period of time, let's say 1 year. At the end of the 1 year would it be true that the twin in space would actually be older than the twin that stayed on Earth? I don't know the actual rate difference between time on Earth and time in space (I would like to find out) but to put some numbers to my example I will assume that time moves 5 times faster in space than on Earth. I know this is not an exact model but I just wanted to put the numbers to it so I can relate my example. According to what I have written, is it true that after 1 year the space twin would be 5 years older than the Earth twin, assume what I have for the example? 2. Since the effects of gravity dissipate inversely proportionally to the distance from an object, I do realize that the effects of gravity are always able to be calculated regardless of how far away from an object you are however there is a point where it would become negligible. At this point, where the effects of gravity from an object are negligible, what is that rate of flow of time? I guess maybe I am asking how much faster would time flow in deep space where gravity is non-existent in comparison to Earth time? Or maybe a better question is what would be the maximum speed of time flow? If anything requires further explanation, please let me know. Thanks in advance for everyone's input. Also, I think it is very possible I am misunderstanding something and/or not factoring in something important. If this is the case, please steer me in the correct direction.