> there is gear that measures the time to see a light pulse reflect off of the cut end Though not very relevant to your stories about Brazil, it's a neat techn

> there is gear that measures the time to see a light pulse reflect off of the cut end Though not very relevant to your stories about Brazil, it's a neat technique in its own right: https://en.wikipedia.org/wiki/Optical_time-domain_reflectometer https://en.wikipedia.org/wiki/Optical_time-domain_reflectome...