6 ms·

You can use the Fresnel lens in an old projection TV as a laser. https://www.youtube.com/watch?v=OmlXR2nsis4 https://www.youtube.com/watch?v=OmlXR2nsis4

• dvh 6y ago
  Laser is light amplification by stimulated emission of radiation. Fresnel lens doesn't amplify light it focuses it. It is not stimulated, it is just passive component.
  • foxdev 6y ago
    This is true, but I don't think many people think of laser as anything other than "dangerous light." That's how I used it. Colloquial meanings can be frustrating when they clash with the technical meaning, but trying to fight them is typically futile. https://www.merriam-webster.com/dictionary/laser https://www.merriam-webster.com/dictionary/laser >> "2 : something resembling a laser beam in accuracy, speed, or intensity " I gave up on fighting "CPU means the entire computer" a long time ago.
    • klyrs 6y ago
      > This is true, but I don't think many people think of laser as anything other than "dangerous light." "Many people" have taken first year physics, or at least read a wikipedia article, and understand that the defining feature of a laser is its coherence. But, sure. It's 2020. We live in a post-factual society, words have no meaning and it's impossible to know anything. Why resist?
      • deleted 6y ago
        [deleted]