PARENTS: RELATIVITY WORKSHOP WORKSHOPS ARCHIVE =============================================================================== FASTER THAN C ------------- =============================================================================== 1.ROTATING LAMP A rotating lamp sends in the space a rotating ray. For a given rotation speed a sufficiently distant point of the ray moves faster than c. 2.BEACHCOMBER's ROPE A beachcomber, for some doubtless good reason, has stretched a rope intended to be parallel to the low tide line. However, lacking precise tools, he made it nearly parallel, so that with the coming flood the point at which surf waves were hitting the rope traveled along the rope with a very high speed. Theoretically one can imagine an angle small enough for the impact point to travel along the rope faster than c. Now, the beachcomber, no matter how competent, will not be able to carry out the experiment with enough precision. But if we replace the surf with a light wave and the rope with a glass surface, any angle between 0 and 90 degrees will be good enough for the impact point to travel faster than c. NOTE: This issue is not a puzzle, but an exercise in Special Relativity in its original Einstein's version. Thus, it should be considered from within the SR and only with help of SR's Axioms, Definitions and Theorems. Awaiting comments. HINT: Have a look at STRUCTURE OF SCIENTIFIC THEORY =============================================================================== PARENTS: RELATIVITY WORKSHOP WORKSHOPS ARCHIVE