Japanese Ice Sphere Mold

A few months ago, I found a video of an awesome “Japanese Ice Mold” online. The idea is simple:

• People like drinks cold.
• Ice makes things cold.
• Ice melts.
• People don’t like water in their drinks.
• To prevent melting, you should have the maximum volume (making things cold) with the minimum surface area (melting).
• The shape that does this is called a sphere.
• It’s hard to take water and make spheres that don’t have ugly seams in them.
• Through the magic of thermodynamics, you can use a metal to melt some parts of a block of ice, while freezing the resulting water, and get a beautiful sphere.

At this last bit, the physics student in me is screaming “but that makes no sense!” Admittedly, I didn’t do very well in physics, so it wasn’t screaming very loudly. I really thought that my brother, Quinlan (who’s a liquor snob and has more parties than I) needed this for a party. However, the fact that it costs freaking $1400 put it well out of my range; Quinlan didn’t need it that badly. As I looked at it, though, I realized that it wasn’t a hard concept: just get a big block of aluminum with a spherical hole, heat it, and you’re done. Surely, I could make this. If only I was a member of a hackerspace with milling tools… but wait! I am!

For more, check out Making the Mold at Times and Measures.