http://en.wikipedia.org/wiki/Ladder_paradox#Man_falling_into_grate_variation In the resolution it says: "It should be stressed that, since this bending occurs in the rod's rest frame, it is a true physical distortion of the rod which will cause stresses to occur in the rod." I wonder if this is generally accepted. As we assume uniform acceleration in outer frame (the downwards pushing force acts on all parts of rod simultaneously), the different parts of rod are never moving respect to each other, so no stress should occur. Also the stress on rod sounds like an absolute event that all frames should agree. The stress could even break the rod, which certainly all frames must agree whether or not it happens. It seems that in rod's own frame there is some bending caused by relativity of simultaneity (different parts of rod seem to get acceleration at different times), but I think this kind of apparent bending doesn't need to have physical significance i.e. stress or breaking. My guess would be that there is no physical bending in either frame. Any ideas? Thanks.