On Monday, June 29, 2020, 09:50:46 AM PDT, Karl <gmkarl@gmail.com>
   wrote:
   >Jim put a lot of energy here into replying to a joke.
   I'm not aware that:
   "Scientists in China managed to exchange a crypto key at a distance of
   over 1,000 kilometers"
   >"Wow!"
   >"How can they do that?"
   is a joke.
   Actually this 50% a joke 50% serious, since the initial article did not
   mention anything about using Quantum Entanglement and so as such the
   challenged looked as if we were in ... 1820...

   now for the 50% seriousity, I wonder how they can really use quantum
   entanglement at such a distance ... I am sceptical there and it would
   be marvelous if they really achieved what they claim they achieved...
   quantum entanglement over more than 1,000 km of distance...  you flip a
   bit, it gets 'instantaneously' flipped on an other part of the world,
   located at 1,200 km distance, information without matter movement, at a
   speed (much) faster than light.

    I got the explaination from Jim, still besides the obvious issues with
   the cables etc... such phenomenon as quantum entanglement relies on
   very complex experimentation and so I am not convinced at all that what
   they exchanged ( cryptohgraphic keys but in that context doesn't relaly
   matter ) was not used by "ordinary" communication, eg with matter
   displacement.