Force of sound

The sound wave is longitudinal and has pressure variations. Half a cycle is compression (overpressure) and the other half cycle of a sound wave is underpressure (below ambient pressure). When a spherical sound wave goes outward, it exerts outward pressure which pushes on you eardrum to make the noises you hear. Therefore the sound wave has outward force F = PA where P is the sound wave pressure and A is the area it acts on. When you read Raleigh's textbook on 'sound physics' (or whatever dubious title it has), as I have done, you see the fool fits a wave equation from transverse water waves to longitudinal waves, without noting that he is creating particle-wave duality by using a wave equation to describe the gross behaviour of air molecules (particles). Classical physics thus has even more wrong with it becaus of mathematical fudges than modern physics, but the point I'm making here is that sound has an outward force and an equal and opposite inward force following this. It is this oscillation which allows the sound wave to propagate instead of just dispersing like air blown out of your mouth.

Note the outward force and equal and opposite inward force. This is Newton's 3rd law. The same happens in explosions, except the outward force is then a short tall spike (due to air piling up against the discontinuity and going supersonic), while the inward force is a longer but lower pressure. A nuclear implosion bomb relies upon Newton's 3rd law for TNT surrounding a plutonium core to compress the plutonium. The same effect in the Higgs field surrounding outward going quarks produces an inward force which gives gravity, including the compression of the earth's radius (1/3)MG/c^2 = 1.5 mm (the contraction term effect in general relativity).