This is a "paradox-type" relativity problem that I cannot figure out. Hope it's OK to post this here. Sorry for English errors, it's not my native language. Here it goes: Railway. Platform (1 km) by side of it. Train (100m). Train approaches platform very high velocity, so that (in train's reference frame) the platform is only 10m long. The personnel in train can calculate the moment when the mid-point of train is exactly at the mid-point of the platform. Train brakes are set to operate at that moment. All cars of the train will start braking at the same time (all cars "live the same time", at least until the braking). No messages need to be passed at the time of the braking. Deceleration is very strong, but not "infinitely" strong (we can allow a small stopping distance for the train, few centimeters for example). Now, what is happening from the viewpoint of different observers? An observer at the platform will see very short train approaching, braking and stopping at the mid-point of the platform, and "stretching" to its original 100m length. But an observer at the first car of the train will observe very different event. Short (10m) platform approaches and passes him by. No braking yet. Instead, the passenger sees terrain beyond the platform. He can even leave mark there (say, toss a candy paper out of the window). After a short but non-zero period of time, braking starts. Then he finds himself in a train, at halfway of 1km long platform. How can it be? In platform's reference frame train never passed the platform, not even reached the end of the platform. In passenger's reference frame train went past the platform, and the passenger even left a mark there. The mark (candy paper) should be there. How can it be, if the train never passed platform? What went wrong?