5 ms·

You can even see the discontinuity clearly in the linked article

• synecdoche 2y ago
  A discontinuity being an exception from a great majority of surface consisting of spiralling and continuous lines is no proof, nor debunking. A spiral form being an exception from a great majority of circular lines may be just that, an exception, and would point towards a non-spiraling cut. The photo with the discontinuity shows one side only. Therefore there is no way of knowing if and how the lines are connected on the obscured side, and no conclusion can be made either way.
  • deleted 2y ago
    [deleted]
  • abakker 2y ago
    Important to distinguish a spiral cut from a spiral ream. It is entirely possible to chip/drill/chisel a hole, and then to ream it out with a spiral tool.