I know that the relativistic effects really do happen, such as time dilation and length contraction. However both frames of references predict these effects in the other frame of reference. It is said that these effects really happen in both of them, due to relativity of simultaneity. The thing is that I don't really believe in relativity of simultaneity. Isn't it possible that only one or none of the frames of references make the right prediction. The other frames prediction is then wrong? The measurements between each frames are different events from the ones being measured. Consider this example. There is observer A on the ground and observer B on a train. Observer A sees two lightening bolts strike the train at both sides simultaneously. Observer A sees that observer B observes the light from the front lightening bolt first, because he travels towards it. Observer B sees that the front lightening bolt strikes at first and then the one behind. He predicts that observer A sees them simultaneously because the lightening bolt at the back strikes when the light from the front bolt is at the same position. So the question is, why aren't just one or none of these predictions the right one according to more absolute properties of time and space? In the end when two observers arrive at an equal frame of reference, it is only one of them who shows relativistic effects.