Have you ever had this unusual occurrence in your freezer? This one observant science teacher says
:
We had a single stalagtite form from one cube in an ice cube tray. It rose about an inch, no more than an eighth of an inch in diameter, and tapering to a sharp point. How did that form?
Paul Doherty (physicist extraordinaire) answered that this is called an ice spike.
The water in an ice cube freezes from the outside in. Once the outside is sealed the water inside freezes and expands.
So the interior water is pressurized.
If it freezes at just the right rate the pressure can push the liquid water out of a hole in the top surface and freeze it.It helps if the water is clean and free of nucleation sites i.e. distilled
See this website here for a bunch more information and great pictures.
Related posts:
- Geeky Treats #4: Freezing food is cool Got liquid nitrogen? Apparently you can have an awful lot...
- Making light rays in the classroom In optics experiments, you often need to create lines of...
- Things to do in a microwave #1: Find your microwave hot spots I’ve been wanting to do a series of posts on...
- Teaching non-majors Light and Color (and making them love it) I sacrificed my June and my sanity this summer to...
- Chemical apple pie A tip of the apron to Elnore Grow for this...
Related posts brought to you by Yet Another Related Posts Plugin.


{ 3 comments… read them below or add one }
Nifty! My freezer is full of stalagtites from a dodgy seal I think, not nearly as cool.
Ahh yes…
So much coolness involved with ice and snow.
Such a huge range of physics are involved.
http://scientificilliteracy.blogspot.com/2009/10/snowballs-chance-fpotw.html
Cool, I just googled this because my ice-cubes have been doing this since I starting using the Brita pitcher to fill the tray.
So thats an easy step for anybody who wants to recreate this.
Dave