In Special Relativity the example is given of a pole that alternates color, as seen in its own rest frame. Someone in a different frame is supposed to see the pole as striped, because he sees a different slice through 4D spacetime--a slice that includes past and future states of the pole mixed together. My question is whether such a striped moving pole can have other properties that wouldn't occur in the pole's rest frame. What if it was alternately composed of materials that would explode upon contact? Or waves of different frequencies in a medium, how would they join together? Is my question missing something essential about the process of changing the frequency or the material composition? Or is it missing something about the privilege of proper time in physical processes? Or have I taken the "different slices through spacetime" idea too seriously?