Soap bubbles in laser light

Question

I have experienced an interesting phenomenon this weekend. It involved :

1. Soap bubbles which were ...
2. ... flying around while laser light was drawing images around the walls
3. All this accompanied by loud music

(some people would call this place a discotheque)

The following happened: When the soap bubbles were hit by the laser, they sort of lost their shape ... became lifeless shells of themselves and just fell to the ground.

A video of the entire phenomenon is available at

https://youtu.be/w2LCb5UWmRo

There are dead bubbles falling around all the time, but the best example is in the last second, when a big bubble was captured losing its shape and falling.

Can someone explain to me in human terms what caused these bubbles to experience the loss of shape?

Answer 1

I am not convinced the lasers have any effect on the bubbles. There seems to be a height at which they are affected, but they then seem to normalize once below that point, suggesting a small air current maybe.

I would like to see this experiment performed in a more controlled environment, especially with stationary lasers and bubbles. Until that happens, I think you have made a causation error.

Answer 2

From what I can tell from the video, the bubble formula used contained an adhesive which allowed the bubbles to dry in shape. Otherwise the bubbles wouldn't just lose their shape/deflate, they would pop and disappear.

If adhesive was used in the formula, it seems plausible that the laser light could cause the adhesive in the bubble formula to dry out very quickly (either via heat or photochemical reaction), causing a tear in the membrane. Then the bubble deflates, which causes it to lose buoyancy and fall down.

Answer 3

I admit I don't notice the phenomenon in your video. Assuming, however, it does take place, the mechanism could be as follows. The laser beam heats the film of the bubble in some place, evaporation increases in that place, soap solution from the sides replaces the evaporated water, and we have cooling of the bubble by evaporation. Such cooling can be quite intense (see http://preprints.lebedev.ru/wp-content/uploads/2011/12/2007_6.pdf , pp. 28-29, it's in Russian, but one can Google translate it). As a result, the air inside the bubble cools down, the bubble shrinks and loses buoyancy.