Hello everyone. I just kicked myself out of the philosophy section of the forums, and came here looking for some intelligent conversation at last. I'd like to ask a question about relativity that has been puzzling me for a long time. By looking at these threads it's hard (for me anyway) to be sure whether all physicists agree on the nature of time dilation in SR. That is, whether moving clocks really tick slower or just appear to do so. I used to think the clocks actually ticked slower, but I have seen physicists argue that it's only appearances. So what is it really? What is the official position regarding time dilation in SR? If time dilation is real, in a physical sense, I'd also like to understand what is the physical cause for the slower rate of moving clocks. Given that movement is relative and dependent on another frame of reference, how can real phenomena arise out of the act of observation? In other words, how can my clock tick slower just because somebody else is in uniform motion relative to me? (I think the apparent contradiction in that question may imply that time dilation for bodies in uniform motion is not real, but I'm not an expert on the matter) As a bit of background on myself, I'm an electrical engineer with an amateurish interest in physics. Since I do not work in the field, some issues about relativity can be hard to understand. I hope you experts will be able to help me. Thanks everyone in advance.