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.

 

Source: http://physicsweb.org/articles/news/9/11/1/1

 

 

What do you all make of this?

It's an interesting article, it sounds a bit like the transmission of spread spectrum signals, which are dispersed on transmission and compressed on receiving.

 

Seems like he's using the plastic balls as an acoustic dispersive delay line, just can't see where the speed of light comes in.

This is a common example of a well known totaly with in the laws of physics effect known as anomalous dispersion.

 

There are many many threads about it... here's just one:

http://www.scienceforums.net/forums/showthread.php?t=7718

use the search button to find many more!

This is a common example of a well known totaly with in the laws of physics effect known as anomalous dispersion.

 

There are many many threads about it... here's just one:

http://www.scienceforums.net/forums/showthread.php?t=7718

use the search button to find many more!

 

Correct me if I'm wrong but isn't Anomalous Dispersion something that effects light, not sound?

Anomalous dispersion effects a wave... sound is a wave (as is light).

Correct me if I'm wrong but isn't Anomalous Dispersion something that effects light, not sound?

 

You're wrong.

Thanks for the information