Water Quality Dependence of Sonoluminescence Light Emission

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Water Quality Dependence of Sonoluminescence
Light Emission

• By Stephen Hurley
• Senior Physics Lab, Undergraduate Physics
  Department at UCSB

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What is Sonoluminescence?

• Sonoluminescence is the emission of pulses of
  light by gas bubbles in a liquid.
• Bubbles are drawn to compression nodes.
• They shrink rapidly and emit light.
• No one knows how!

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Hawking Radiation Theory

• Small bubble size limits virtual photon pair
  creation by wavelength.
• Bubble compresses fast because there is lower
  energy inside than outside.
• Bubble wall moves so fast, virtual photon pairs
  cannot recombine (annihilate).
• Photons escape and light is emitted.

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Properetti's Theory

• Bubble is imperfect shape. It has cracks.
• Tiny jets of water fly into and across the bubble
  at 6000 km/h.
• The jet hits and cracks the other side.
• Light is emitted.

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Experimental Setup
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Our Qualitative Results

• We used highly filtered DI water (Milli-Q) in
  initial tests. Didnt work.
• We used regular DI water in one last attempt.
  Worked great!
• Within 15 minutes we achieved light.
• Bubbles stayed bright for gt 15 min.

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Conclusion

• Debris in water helps bubbles emit light.
• If Properetti's Theory, then debris might help
  create fractures.
• More experimentation necessary.

8
Thanks

• Lab partner, Adam Elhardt.
• Professor Sherwin, TAs, and Bob
• Everyone listening!