Information transmitted at speeds greater than C

[alex.enduro73]

Hello,

a question for all of you with its experiment.
If I have a material that has a Bulk modulus higher, the diamond type (442 GPa) if I create a tube of diamond along 1 miles (or length less) with appropriate supports to decrease as much as possible the friction.
At the same time I have a source with a beam of light, and on the other end I receiver measures the time that I was late arriving light.
The tube ends in a diamond has a servo for actuating the movement of longitudinal movement that can be recorded from the other end with a sensor.
By activating both instantly (or in sequence it is important to measure the latency), motion tube diamond and activation beam of light, which would be the information that will come first?
If it should be noted the movement of the tube with a latency less than the arrival of the light beam will have discovered a way of communicating information faster than light. thanks
Alexander

 

[A.T.]

A mechanical signal is never faster than light, because on the atomic level it is also based on EM forces. I recommend you this video:

 

[CWatters]

Lets say you hit the end of the diamond tube with a hammer. The shock wave will travel down the tube at the speed of sound in diamond which according to this web page is "only" 12,000 meters per second. Quite a bit slower than the speed of light.

http://www.engineeringtoolbox.com/sound-speed-solids-d_713.html

The speed of sound in any material cannot exceed the speed of light for the reasons given in the video at about 4mins in.

 

[Nugatory]

There is a FAQ on this topic over in the relativity forum:

https://www.physicsforums.com/threads/can-i-send-a-signal-faster-than-light-by-pushing-a-rigid-rod.536289/