Status of waves?

Question

Hi every1. I wanted to know why sound waves cannot travel in vacuum and why electromagnetic waves can travel in vacuum.
For my part, I reasoned that sound waves cannot travel in vacuum because vacuum does not contain air particles. since we hear sound due to layers of air being shifted till it reaches our ears, I thought that sound waves maybe can travel in a vacuum but we will not hear the sound. That is sound waves travel like electromagnetic waves. The latter do not shift layers of air to cause sound. Hence they can travel. So I think that sound waves actually travel in vacuum but without making any sound.
Please tell me whether I am right or wrong and answer the questions I asked before. Also tell me whether EM waves do cause vibration of particles, and if yes, in vacuum what vibrations do they cause.

Good luck for the answer and I hope I get a good one :)

Answer 1

Sound waves are are not composed of particles, so they need a medium to propagate through. Basically they are caused by disturbance and in a vacuum there is nothing to disturb. The waves that sound creates are not physical themselves. They create waves in the medium so without a medium they don't exist at all. Electromagnetic waves do not need a medium to propagate because they are composed of particles (photons.) In a sense, they are their own medium.

Answer 2

There are no sound waves in a vacuum.
Sound needs atoms to transmit the wave. In a vacuum there are no atoms.

Your logic is sort of like saying that water waves could travel in a dry lake bed, you just wouldn't be able to surf on them.

Electromagnetic radiation is generally described as a self-propagating wave in space with electric and magnetic components. These components oscillate at right angles to each other and to the direction of propagation, and are in phase with each other.
Electromagnetic radiation are waves of electrical and magnetic energy. There are no particles involved and therefore can travel through a vacuum.

Answer 3

Electromagnetic waves are the interaction of electric and magnetic fields as described by Maxwell's equations. These equations show that a time-varying magnetic field creates an electric field, and conversely, a time-varying electric field creates a magnetic field. The equations can be solved to derive the case in which the electric fields and magnetic fields vary in such a way that each creates the other in a self-sustaining interaction. When this is done, the result is an equation of a travelling wave that moves at the speed of 1/sqrt(e0*m0) in free space. e0 and m0 are electrical properties of space called permitivity and permeability. it turns out that the speed of light in a vacuum is exactly that value.

Electric and magnetic fields can exist in a vacuum, but sound waves are basically the motion of molecules of a medium, and with no molecules, no wave.

Answer 4

Sound waves require a physical medium in which to travel. EM waves are in the pure energy circuit and can travell for unlimited distances. Also EM waves move at the speed of light while sound waves move at aprox 800 mph.

Answer 5

Sound waves are, by definition, pressure waves in a physical medium (not just air, substance).

In a pure vacuum you can not have pressure waves, if you can't have pressure waves, you don't have sound waves.