Light v sound

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fwbb | 21:38 Tue 25th Jan 2005 | Science
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Why does light move faster than sound?



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Something to do with operating on different wavelengths?
Kebab is, essentially correct.. because light is a form of electromagnetic radiation, which is a very powerful form of energy that can travel vast distances in space. A sound wave is a pressure disturbance, which travels through a medium like air by means of tiny particles bumping into each other. Light has much more energy than sound... Since light travels faster than sound, people appear bright... (sorry)
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it is to do with how they propagate.  sound is vibrations, which travel slowly because the particles that vibrate have inertia to overcome.  Light is electromagnetic radiation which travels with no mass, so no inertia.
I think ansteyg's answer has some merit, but it's to do with the differing wavelengths as pointed out by others.
It has nothing to do with wavelength. All electromagnetic radiation from gamma rays (very, very short wavelength) to radio waves (very long wavelength) travels at the same speed. Incitatus has given the correct answer.

incitatus is almost right. It is not the particles that vibrate though. Sound is propigated by a pressure wave, air (for eg). Consider a speaker, the diaphram moves in and out, this compressed the air in pulses. The distance between these is the wavelength. How quickly the sound can travel then depends on how quickly the pressure wave can propigate. This depends on the air pressure.

hamish- pressure waves are propagated by particles- air molecules to be precise.  the reason the speed depends on pressure is because this affects the interparticulate distance (or random walk) and soo affects how particulate collisions can be transmitted.  In a perfect system the delay is solely caused by inertia, but in gases there is an intermediate delay caused by random walk factors
And hot air travels faster than anything.
well after all those answers i have little to add exept that light and sound r two different energy forms. also concerning light it is the same type of energy as radiowaves but has a fantastic requency just think if we could produce a frequenzy that high we would have a 100 % efficient light bulb but that is sience-fiction for the moment sadly
So it has nothing to do with 'vibrations of the particles' as I said.
Light does not always move faster than sound. The speed of both depends on the medium they propagate through. Light in a vacuum is very fast indeed, but scientists have recently managed to slow it down to walking pace by passing it through unusual materials at very low temperatures. Likewise the speed of sound in water is faster than the speed of sound in air...

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