Strange freezer pop behavior. O.o

[Zaeyde]

You know those freezer pop things? The ones that are basically plastic tubes of liquid sugar that you stick in your freezer, cut apart, and eat?

 

Mine are behaving strangely

 

I'll put 10-15 of them in the freezer at a time. I don't lay them flat; Instead I bunch them together and stick them whereever there is a spot.

Theoretically, they'd all get cold enough to freeze, right?

 

No.. Not quite. Sometimes, no matter how long I leave them in the freezer, the ones in the middle will remain liquid.

I dismissed it as them not getting air hitting them, so they won't freeze. Surface area and all that stuff.

 

I hadn't paid much attention to those unfrozen pops. I just threw them back in.

Until today.

 

I noticed one of the unfrozen pops had little globs of apparently frozen material floating at the top. About half the size of my pinky nail.

Mm. Big deal.

I took them out of the freezer... And then something interesting happened. In the open and warm air, those globs expanded from the top down, and in less than a minute had frozen the pop from the top to bottom, leaving me with a smooth, slush like mixture. I could actually watch it freeze downward and crystalize and all that junk.

 

 

So why? Why'd it do that?

[insane_alien]

you just observed a nice example of supercooling.

 

what happens is that the the ones in the middle cooled down slower so they didn't have a really big temperature gradient. this caused the fluid to remain pretty stationary and undisturbed which lets them cool below their freezing point and remain liquid.

 

when you moved them, you provided a disturbance that produced a nucleation site which allowed the mixture to freeze.

 

its a really cool effect and makes a nice party trick.

[swansont]

It's pretty cool when you do that same thing with a carbonated beverage in a glass or plastic bottle. Messy, though. When you open it up the released carbonation initiates the freezing, and it expands all over the floor if you aren't careful.

[insane_alien]

It's pretty cool when you do that same thing with a carbonated beverage in a glass or plastic bottle. Messy, though. When you open it up the released carbonation initiates the freezing, and it expands all over the floor if you aren't careful.

 

and if you got a friend to drink it, it'll expand out through his nose too.