• Question: what causes sonoluminescence?

    Asked by maxsmith1 to Arttu, Ceri, James_M, Monica, Philip on 13 Jun 2011.
    • Photo: Philip Dolan

      Philip Dolan answered on 13 Jun 2011:

      Once again, this isn’t my field really but I think it’s making light by bursting bubbles. I do however remember a film staring Keanu Reeves and Morgan Freedman called chain reaction, in which they also burst bubbles, but to make clean reusable energy. But then the FBI and CIA get involved and ruin everything.

    • Photo: James M Monk

      James M Monk answered on 13 Jun 2011:

      When bubbles in liquid collapse they can cause very high pressures due to the shock impact of the bubble walls upon each other. In fact, my understanding is that bubble collapse is one of the main mechanisms for erosion of things like boat propellors and water pumps as the shock of the bubble on the propellor blade damages it slightly.

      In sonoluminescence sound waves are used to repeatedly create and then collapse a bubble. The high pressures somehow excite the water and/or gas, which then emits light. Other than the very high pressure I’m not sure of the exact mechanism for the excitation, and in fact I’m not sure anyone knows!

Comments