Question

Can sound waves travel in a vacuum?

Answer 1

The answer relates to the concept of waves since sound travels in the form of waves. The concept behind vacuums and if they allow the generation of sound needs to be probed upon. To know whether sound waves can travel in a vacuum the determination of whether sound waves need a material medium to travel answers the above question.

Complete answer:
Waves are vibrations that transfer energy from place to place without matter actually being transferred. The repeated periodic disturbance that moves through a medium from one location to another are called waves.Sound is a form of energy that is produced by the vibration of particles leading to a production of waves in a medium.

These waves are the ones which carry the sound energy across the medium. A medium is a substance or a material that carries the wave and this can be solid, liquid or gas. Vibration can take place due to production of either of the two types of waves. One being transverse waves and the other being longitudinal waves.

Sound waves are said to be longitudinal waves as it was observed that these waves produce oscillations which are along the same direction of travel and energy transfer which means that their direction of motion was said to be parallel to the direction of travel of these waves. Longitudinal waves produce a series of compression and rarefaction regions. The longitudinal waves were known as pressure waves due to this reason.

Compression is a region of the medium in which there is a temporary decrease in volume and a consequent increase in density of the medium. Rarefaction is a region of the medium in which there is a temporary increase in volume and a consequent decrease in density of the medium.

Since sound travels through compressions and rarefactions there is said to be a way in which the energy carried by one particle in the waveform to transmit energy to another particle in the waveform so that the process continues until the sound reaches its destination. This may take place due to the collision and the subsequent transfer of energy from one atom to another. Hence, we can conclude that sound waves need a material medium to propagate.

Knowing this, we can conclude that sound cannot propagate through a vacuum due to the absence of any kind of atoms or molecules in it. Since a vacuum is just an empty space the sound does not have a medium for it to travel through and hence there is no bumping of atoms into each other and thus it will not be able to transfer any energy. Since there is no material medium for it to propagate the sound waves cannot be generated.

Thus sound waves cannot travel through a vacuum.

Note: Various experiments can be used to show that sound waves require a material medium to propagate like for example the bell jar experiment. We consider space to be a vacuum and hence due to the absence of atoms or molecules or in other words due to the absence of a medium the sound of our own voices cannot be heard in space. However, light can travel in a vacuum as they are electromagnetic in nature.