Its just simple physics and geometry.
The guy above is Bubbleman. Bubbleman is the bubble king. He shows us how to blow a square bubble about a minute into his epic performance.
That man is doing what he loves. We should all be so lucky.
Bubbles naturally “want” to be a sphere because the liquid surface and the air within “compete” causing pressure to be evenly distributed throughout the whole bubble. Evenly distributed pressure from within creates a sphere with the maximum possible volume, and minimal amount of surface area.
However, you can create square bubbles… (They are actually cubes)
The Physics of Square Bubbles
So, how does this work?
When two bubbles meet, a flat surface forms between the two. This happens because the pressure from both sides is equal, so there is no force causing the soap-film to distort one way or the other.
Now, when Mr. Bubbleman blew his square bubble, you’ll notice he actually blew 6 bubbles to begin with — two vertically, and 4 horizontally. This created a space in the middle, into which he blew another freaking bubble.
This middle bubble is being pushed on by all the other bubbles, creating 6 flat sides — a cube.
Photo: Deni Yang
Now, in reality, it would be nearly impossible to produce a perfect cube through this method. As you may of noticed, the “walls” of the middle bubble are curved, as opposed to the flat walls of a cube.
In order to produce a perfect cube, one would need to blow 6 bubbles with the same exact volume, and the interior bubble would need to have the perfect amount of volume to ensure equal force from each of the exterior bubbles.
Even Bubbleman would have a tricky time pulling that off.