Is length contraction relative or absolute?? This is from the book "Speakable and unspeakable in quantum mechanics" by J.S. Bell. Three small spaceships, A, B, and , drift freely in a region of space remote from other matter, without rotation and without relative motion, with B and C equidistant from A. On reception of a signal from A the motors of B and C ignited and they accelerate gently. Let ships B and C be identical, and have identical acceleration programmes. Then (as reckoned by an oberver in A) they will have at every moment the same velocity, and so remain displaced one from the other by a fixed distance. Suppose that a fragile thread is tied initially between projections from B to C. If it is just long enough to span the required distance initially, then as the rockets speed up, it will become too short, because of its need to Fitzgerald contract, and must finally break. It must break when, at a sufficiently high velocity, the artificial prevention of the natural contraction imposes intolerable stress. Is it really so ??