QuoteOriginally posted by: Richyieeyou keep on coming back to this "feeling acceleration", its just not very convincing ;p . If there only existed 2 things in the universe, tom and jim, and we observe the distance between tom jim was getting shorter, you could say tom was accelerating towards jim, or you could say jim was accelerating towards tom , or they are both accelerating towards each other, why do you keep insisting on one being the prefered frame of referenceIncorrect. There is no preferred frame of reference. The usual example is if you are in a lift travelling at a constant speed, you cannot tell if you are moving or not (i.e. there is no experiement you can perform without opening the doors and seeing if the floors are zipping by). When the lift accelerates you cannot tell if it is gravity that has increaed or whether the lift is now accelerating (again no experiement is available to explain what is causing the acceleration). Hence all frames of reference at a constant speed are equal, all frames of reference at a constant acceleration (regardless whether it is gravity of an energy input) are equal. However I can perform an experiment that shows if one lift is experiencing an acceleration or not. Hence acclerating frames and no accelerating frames are different and hence need to be treated differently. Neither is preferred but is shows that the twins paradox is only a paradox because for the paradox to exist an acceleration must have occured, hence the frames of reference are not identical.In terms of your tom/jim example - a distance getting shorter is comparing two frames of reference (via a Lorentz transformation) - and means that there is a velocity, NOT an acceleration (dv/dt). EDIT: Unskyld Collector - cross posting!
Last edited by rmax
on January 31st, 2011, 11:00 pm, edited 1 time in total.