I'm doing a fictional history in near future, where there is a very advanced army but i like to keep things real, and my knowledge of physics is very limited…but i know sound has been used to levitate objects before so i'm thinking about a device that can generate sound to make bullets deviate enough to not hit the target(mostly drones with low armor and soldiers).
I'm already using EMP generators to fry the electronics missiles systems incoming( it's not active all the time, it just generates a strong pulse when missiles are detected for energy reasons) this would be for me limited knowledge the most real and close we can get from sci-fi "force fields" but if anyone have a better and possible real way to block/deviate/fry objects with sound i would like to know.
Best Answer
Here's an article about acoustic version of laser named SASER. http://en.wikipedia.org/wiki/Sound_amplification_by_stimulated_emission_of_radiation
It can emit very directed acoustic field. As far as I know, present versions have quite limited posibilities, but if you're writing SF it may be inspirational.If SASER's wave can propagate in human body, which isn't crystalline, than MAYBE enough reasearch would make it work in the air.
Generally it is possible to emit sounds that deviate objects, for example blast waves or supersonic booms, so it's enough to have SASER powerful enough.
Moreover scientists from reasearchGate agree that directing of sound is possible. http://www.researchgate.net/post/Can_we_direct_sound_like_a_laser_beam_means_can_we_make_sound_linear
But be careful with using such devices in cities, since diffraction may make the sound rebound into your troops.