Jukebox Bubbles

[Uncleburt]

I was recently at a local establishment that had a jukebox. A friend of mine noticed that the bubbles inside the water tubes on the seams of the box would shrink as they moved up to the top, almost to the point of completely disappearing.
I have tried reasoning my way through why this would happen but havent come up with any theory that I am satisfied with. Any idea why this occurs?
Thanks.

 

[IRstuff]

Kind of depends on what's in the bubbles. If the bubbles are from boiling liquid at the bottom, then they contain evaporated liquid, and will shrink and collapse as they cool down.

TTFN

FAQ731-376

 

[Uncleburt]

Is that really practical in a jukebox though?

I wouldnt think there would be any liquid besides water in there due to health risks associated with any other substance.

 

[europipe]

Presumably it's the beautiful Wurlitzer 1948.
Love that thing

 

[IRstuff]

see:

http://en.wikipedia.org/wiki/Bubble_light

The cited 1946 patent describes it as a closed system where the liquid, of low boiling point is boiled and recondensed.

The Wikipedia article claims dichloromethane as the liquid used in the Wurlitzer:

http://en.wikipedia.org/wiki/Dichloromethane

TTFN

FAQ731-376