>>11054189Relativity is a mathematical hack to make Maxwell's equations work in moving frames of reference.
Neither time dilation nor length contraction can be observed to directly affect physical objects, only observations of the light they emit.
The paradox is a confusion about relativistic and proper time, the twins will start the same age and end the same age, having experienced the same proper time span and being synchronized at the start as to how bookkeep time, but will have "experienced" different relativistic times. Proper time, being Lorentz invariant, will not be affected by the travel so their clocks (including biological clocks, thus their age) will stay synchronized, but an ontological reading of Relativity will force the conclusion that their clocks desynchronized with actual, relativistic time.