Can sound waves travel faster than the speed of light? Yes, says Joel Mobley, a physicist at the University of Mississippi in the US. In simulations Mobley has shown that ultrasound pulses could move at "superluminal" speeds when they enter water that contains thousands of tiny plastic beads.Waves moving in a dispersive medium are described by a phase velocity and a group velocity. The phase velocity is the speed at which a wave of a single wavelength moves, and is typically about 1.5 kilometres per second for sound waves in water. However, pulses of light or sound actually contain a range of wavelengths that all move at different speeds: the group velocity is the speed at which the pulse itself moves. In recent years, it has been shown experimentally that the group velocity of a laser pulse can exceed the speed of light in vacuum -- 300,000,000 metres per second -- in certain situations.

However, special relativity is not violated in these experiments because they do not involve the transfer of information, matter or energy. Mobley has now calculated that the group velocity of a pulse of high-frequency sound waves could be increased by five orders of magnitude by sending it through a small chamber that contains about 8 millilitres of water and some 400,000 tiny plastic spheres. This means that the group velocity would exceed the speed of light in vacuum. The spheres have diameters of about 0.1 mm and account for about 5% of the volume of the water-bead mixture.

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This is good news. I wonder how this will all develop.

hmmmm interesting experiemnt....what will this concure forward?...surely it would be used for extraterrestrial communications right?

i beleive we have an answer to if sound can travel faster than light....those human telephones seem to work miraculously to me!

If I understand the experiment , then his thinking is flawed and inaccurate. Sending ultra sound through a water and plastic bead's medium converts the sound to kinetic energy. Packed mater against packed mater transfers motion at a very fast speed. Like thous ball's in the Science rooms where you drop one ball at one end , and the ball at the other end moves. Thats no longer sound , but kinetic or inertial force. Or so I understand?

I understand where you are coming from but this is also true with regular sound waves.

it seams so i think sound can travil faster well have to run a test

Can you hear me now?

This is a result of Anomalous Dispersion, it's nothing new.

breaking the speed of light is impossible, in order to even reach the speed of light, all motion has to be removed from time, that alone is so far impossible, and to exceed the speed limit....forget about it

Forget about what?

if we cant match the universes speed limit (speed of light) how can we break it? we cant, its also impossible

its like having 5 cookies in one jar labeled space and 5 cookies in another jar labeld time

if you put the cookies in the time jar into the space jar you cant end up with 11

.

Boooo.

no actually, even if you bend time and space, you still cant exceed the limit, if your refering to worm holes, you may beat light to a certain point in the universe but thats becasue your taking a short cut, your not traveling through the short cut at greater than light speed though

I thought the subject was Sound Waves traveling at or above Light speed through a water medium ?

wow!