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This is a tangent, but it's crazy that we've built a communications network that relies on basically LEDs shining out of our pockets (with less interference fro

This is a tangent, but it's crazy that we've built a communications network that relies on basically LEDs shining out of our pockets (with less interference from the sun, but still).

swiley 7y ago
Except our pockets (unless you wear tinfoil pants) and many other materials are transparent at those wavelengths which makes it a lot less crazy.
- StavrosK 7y ago
  You don't think making an antenna that can detect an LED shining in a flat miles away is crazy because pockets are transparent?
  - swiley 7y ago
    No. Amateur radio operators have done it, and it’s not difficult to imagine how one would.
    - StavrosK 7y ago
      Indeed, nothing is difficult to imagine how to do if the method is common knowledge.
    - burnte 7y ago
      That doesn't make it any less amazing.
  - lolc 7y ago
    In darkness our eyes can easily detect a 1W LED from kilometers away.
    - StavrosK 7y ago
      But can they distinguish a specific 300 mW LED in a stadium with tens of thousands of other LEDs next to it?
      - pcnix 7y ago
        If it were a different color, yes. If each of them were a different color, your eye would still be able to, as long as you had enough focus. So the analogy holds pretty well.
      - swiley 7y ago
        My understanding is that healthy human eyes are able to detect individual photons.