• Maggoty@lemmy.world
    link
    fedilink
    arrow-up
    2
    ·
    9 hours ago

    I’m pretty sure that’s just precision grinding glass and setting it at the right distances.

    • JohnDClay@sh.itjust.works
      link
      fedilink
      arrow-up
      1
      ·
      12 minutes ago

      But getting the precision shape to grind in can be hard. There was something about dripping liquid glass just right, but that may have been professional espionage to throw people off.