One of Alcademics' readers figured out a simple way to make perfectly clear ice balls by using a silicon ice ball mold, a piece of wire, and a pot of water.
His name is Craig Belon and so he calls it the Belon Method. No actual parrots are required.
[update: Check out easier ways to make clear ice balls at the Index of Ice Experiments]
The method is this:
1. Get yourself a silicone ice ball tray like this one that comes in a pack of six.
2. Over a pot of water (or better yet, a cooler as that will produce lots of clear ice) make a wire loop that the ice ball mold will sit on.
Dunk the filled ice ball mold into the pot of water with the hole FACING DOWN. As you pull the mold up out of the water to set it on the wire. The water should stay inside the ice mold rather than running down into the pot. That's the whole trick.
As I figured out during all the ice experiments, the water freezes directionally from the coldest place to the warmest; and the first parts to freeze are perfectly clear whereas the last area to freeze is cloudy from trapped air, impurities, and pressure cracks.
In a typical ice cube, that's outside-in, with the cloudy part in the center. In the Cooler Method I force that to be top-down. Using this pot the water will freeze from the outside-in, but the big pot creates a big heat sink so the top will be clear until after the ice ball is fully frozen.
So with the hole in the ice ball mold facing the bottom of the pot, as the water in the mold turns to ice and expands, it pushes out the extra air-filled water out the hole into the pot below.
5. Let it freeze, then remove it.
For those of you who want to freeze more than one ball at a time, I'm guessing you could simply make multiple loops in the wire to hold multiple ice balls, but suspend it over a cooler (as in the Cooler Method) instead, as that is all freezing from the top-down. And at the end, you'd have a bunch of ice balls plus a slab of clear ice with which to make cubes.
Belon also included a way he likes to drink absinthe using an ice ball.
"Flawless Absinthe" by Craig Belon
1 Ice ball using the Belon Method
1 Absinthe glass (essential due to its shape)
1 Sugar cube
-place just enough absinthe into an absinthe glass to fill the bottom bulb part
-Insert Belon Method ice ball, corking off the absinthe in the bottom
-SLOWLY add water to the top over a sugar cube in the standard absinthe preparation fashion.
Physics: the water is denser than the liquor anyway, but with sugar dissolved especially more so. This water will flow around the miniscule gap between the ice ball and the edge of the glass, further cooling it. It will slip past the ball to the bottom of the glass, forming an absinthe-sugarwater interface in the bulb that slowly rises, producing the characteristic white precipitate.... but only at the interface! The fluids of differing densities will remain mostly unmixed over the course of 5-10 minutes, with a rising line of precipitate, until most of the absinthe is on the TOP of the glass, freezing, (it started at the bottom) and still crystal clear, and the sugar water at the bottom. This process produces a beautiful cascading effect (properly: Schlering lines)
What this means is that the drink actually starts as a pretty stout swig of pure absinthe that is frigid-cold, and as you drink it changes to become sweeter and sweeter.
A cocktail that changes as you drink it, each sip different than the last. Thanks to physics.
An index of all of the ice experiments on Alcademics can be found here.