Reply to Comment on 'Analysis of scissors cutting paper at super luminal speeds'

We agree with Chandru Iyer's comment on our paper [1] that, in some cases, it is possible for the direction of the cutting of the paper to be different for observers in different inertial frames. However, our paper detailed four different scenarios where scissors cut paper, and there is not always a single frame that can be attributed to the frame of the moving (upper) scissors blade in each scenario. In particular, in the scenario where the upper blade is solid and rotates about an axis, no single inertial frame can be attributed to the entire upper blade. In the two other scenarios in our paper where the upper blade is actually a laser beam, again, no single inertial frame can be attributed to the entire upper blade.

The only case in our paper where the upper blade can be described by a single inertial frame is the 'guillotine' case, where the entire upper blade falls with a constant speed toward the lower blade. Even in this case, though, the inertial frame attributable to the entire upper blade is moving only perpendicular to the direction of the cutting of the paper and so will not reverse the apparent direction of the cut. However, observers in an inertial frame moving with a component parallel to the direction of the cutting of the paper, and fast enough relative to the inertial frame of the paper, will perceive, collectively, that the paper is being cut in the opposite direction to that perceived collectively by observers in the inertial frame of the paper. We thank Chandru Iyer for pointing out this interesting possibility.