Firework Cubes

Wow, I just saw the best fireworks display in my life. Firework technology, why haven't they brought these cutting edge developments to the rest of the firework deprived country. I can't explain most of them, because in words they sound like they do what any fireworks do, but when you're watching these, you think "how is this possible? can fireworks really travel at that speed in that formation? how on earth.." They had firework hearts, and firework numbers (2,3, and 5), and firework multicolored smiley faces.. but most impressively, they had firework cubes.

How is that possible? Firework cubes? Straight lines and angles shot up from a bunch of powder setting off in the sky? What?

This reminds me of some challenge I'd heard about, where a guy was claiming that he could blow bubbles into any shape, and someone challenged him to make a bubble cube. The mathematics of soap bubbles have actually been studied extensively, as they have the amazing property that they will always find the smallest surface area between points or edges. So for one single bubble, this means a sphere (spheres have the smallest surface area for a given volume). For multiple bubbles, this means complex interacts that still follow these rules. So how do you make a bubble cube? Blow six bubbles for the sides of a cube, and they are bound to make a cube in the center! (Disclaimer: They are not perfect cubes, since when 3 bubbles come together they make angles of 120 degrees, but this just means the sides of the cube just curve inwards/outwards a little bit to make up for it.)

I wonder if they had to figure out a cool thing like that for these fireworks. Beautiful.