Contrast between sound waves and light waves Can sound waves and light waves be in contrast between them? They are both waves and so I think there will be destructive waves and constructive waves. But I never see this phenomenon...maybe because isn't possible? But they are waves, they don't move on different plans. Maybe they don't combine. Anyone can help me?
 A: Waves can interfere constructively or destructively only when they oscillate in the same medium. Sound waves oscillate in matter (solid, liquid, gas); these sounds waves oscillate in air. On the other hand, light waves oscillate in the background electromagnetic fields. Light may travel through air, but it is not air that oscillates as the light moves. This means sound and light, while they can interact in some limited and slightly cool other waves, do not combine to constructively nor destructively interfere.
A: Sound waves are called as Pressure waves which require medium to travel. refer this link.
http://www.physicsclassroom.com/Class/sound/u11l1c.html
Light waves are EM waves which doesnt need medium to travel. refer this link
http://bestanimations.com/Science/Physics/Physics3.html
because they are heterogeneous waves they cannot interfere.
And to the comment that infrared and light wave>> infrared is a light wave by itself
sciencedemonstrations.fas.harvard.edu to know the interference of all light waves gives you that pattern.  
