Monthly Archives: September 1999

Sonoluminescence

Lets talk about a very interesting phenomenon the reason for which is still unknown .

Sonoluminescence is the emission of light by bubbles in a liquid when

excited by sound . It was discovered in 1934 .

SImple enough : Make a small bubble in a liquid . throw some sound on it

and it emits light . Wow !

 

It is an unstable phenomeneon and lasts for a very short time .

It is still a mystery in the Physics world because  nobody

understands how a low-energy-density sound wave can concentrate

such a lot of energy in such a small volume to create light .

ANd the emitted light has a very short wavelength ( ultraviolet) .

This means that it has very high energy . The observed spectrum of

light indicated that the bubble is atleast 10,000 degrees Celsius .

 

Physicists think that they can use this huge energy to cause fusion

if the bubble is hot enough and the pressure is high enough then

thermonuclear fusion( a reaction that causes Sun to burn ) may be

a possibility .

 

More interesting facts about Sonoluminescence :

 

1. light flashes from the bubble last for very short times < 12 picoseconds.

 

2. The bubble has to be really small ~ 1 micrometer in diameter .

 

3. Single bubble sonoluminescence tends to be stable .

 

4. Addition of small amounts to nobel gas to the bubble increases the

   intensity of emitted light drastically .