4 ms·

Could this be used for making something perfectly black or something like that? There was an A.C.Clarke story about a silence machine that reemits the sound wit

Could this be used for making something perfectly black or something like that? There was an A.C.Clarke story about a silence machine that reemits the sound with a delay to cancel it.

Throwaway1771 6y ago
Re-emits the opposite sound?
- foobarbecue 6y ago
  Like noise - canceling headphones, presumably.
  - TheOtherHobbes 6y ago
    Exactly like noise cancelling headphones. Also like any number of industrial noise cancelling systems.
tzs 6y ago
The story is “Silence Please” (1). (1) https://en.wikipedia.org/wiki/Silence_Please https://en.wikipedia.org/wiki/Silence_Please
_underfl0w_ 6y ago
Not a physicist, but this might not work quite the same since light is both a particle and a wave, whereas sound is just a pressure wave on a given medium. Would happily be proven wrong though! Seems like the cancelation happening in your scenario would likely be from a delay of half the period of the sound waves, effectively making them roughly "complementary" or "inverse". Can't say I'm familiar with the research, though. On a sillier note, have you heard of the Speech Jammer? [0] It's a device to disrupt a person's speech by playing it back to them with a delay of a few milliseconds. Hilarious results. Also easily reproducible at home if you're bored. [0] https://phys.org/news/2012-09-speech-jammer-ig-nobel-winners.html https://phys.org/news/2012-09-speech-jammer-ig-nobel-winners...