For how long must light be emitted for a human eye to perceive it?

  • Would a person notice a flash of light that lasted 10 ms?
  • Does the intensity of the light matter?
  • How much light is a photon, anyway? Does is take thousands or trillions of photons interacting with the eye to register as light?

1am where I live and I’m wondering

  • NoSpotOfGround@lemmy.worldEnglish
    23·
    17 hours ago

    My understanding of the physics is that there’s no lower limit. People can detect even individual photons.

    As long as the pulse has enough energy to change the state of the material in your retina, you will sense it. Intuitively, if an attosecond pulse can melt steel, you can bet you’ll see “something” if you fire it at your eyes, even if it’s the last thing you see.