# We know that sound waves do not travel in vacuum, how do we communicate with satellites etc. in outer space?

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sound waves work by disturbing matter beside them like dominoes falling, one hits the next and so on. This is why it doesn't work in a vacuum , there is nothing to bump into. electromagnetic waves (light) work differently. the actual photon(particle of light or energy) move in a wave at the speed of light until it hits something. distance is not an issue for light waves because according to the theory of relativity particles travelling at the speed of light, time and distance shrink to zero. So for the light wave it doesn't notice time and distance but for us not moving fast we see it as taking time to get somewhere and travailing far. light waves travel in a vacuum very far before it hits anything so communicating with a satellite is no problem.

Electromagnetic radiations are used to communicate with satellites. Electromagnetic radiations include radio waves, x rays, microwaves, infrared rays. These are short wavelength and high frequency waves which can permeate vaccum in accordance with the theory of the 'dual nature of matter'. This theory states that electromagnetic radiations can travel in the form of both particles and waves.

The reason why sound waves do not travel in vaccum is because vaccum does not have any particles which can promote the transmission of sound through vibration.(sound waves are longtitudinal waves and hence need a pariculate medium for propagation).

However, since electromagnetic radiations are transverse waves and have high frequency they can travel through vaccum.

Sound waves don't travel through a vacuum, but light waves and other radiation does.

Electro magnetic and radio waves can ravel in vacuum. We can not use sound waves to communicate over long distances even on the earth.

Communication with satellites is done through radio waves.

Radio waves are electromagnetic in nature and therefore do not require and "ether" to pass through as sound does. "Ether" in this case means something with body, such as wood, water, air, or and other Liquid, Solid, or gas. Sound works by displacing molecules, in space there are not enough together to spread sound. Thus we resort to radio and the electromagnetic spectrum to do the work of communication for us.

sateelites dont use sound waves they use radio waves which are not subject to the limitations of a vacuum