Why can’t we take the same techniques used to cancel sound waves, and apply it to light waves?


I’m certain there’s a simple explanation, but if there was a way to cancel light in the same fashion as sound-cancelling headphones, wouldn’t you have a practical form of invisibility?

In: Physics

Light isint a wave like sound is. They do not have the same properties.
Photons are kinda like a wave / particle mix.

It would be at least slightly impractical, as then no light would reach your eyes. Sure, you could workaround that, but it still presents a huge problem.

Light waves do cancel just like sound waves, that’s what makes the pattern in the double slit experiment, but you have to be spot on with the alignment to cancel

Sound moves far slower than electronics process so a microphone on the outside can record a sound, flip it around, and be ready to feed it to the speaker before the sound is all the way through the housing. The headphones also only have to cancel sounds that arrive at the opening of your ear

Light moves too fast to detect light hitting a surface, process it, and emit the opposite phase before it bounces away

There are some ways to do it like a thin film where some light reflects off the top of the film and some goes in and reflects off the bottom and comes up out of phase and cancels. This only works for a narrow range of frequencies and only straight on, as soon as you’re off to the side the paths are different lengths and it doesn’t quite work right

There are also highly refractive materials that can bend light around an object but they’re also angle dependent

There’s no easy cheat for an invisibility cloak, armies around the world have spent plenty of time and money on research to confirm