“What I work on is called pattern formation: situations where nature produces some regular-looking structure, which we call a pattern, apparently for free, for nothing. So the classic example is that wind blows across some sand and the sand makes these beautiful little ripples. Where did the ripples come from?”
Stephen Morris, professor of physics at the University of Toronto, studies the science of emergent patterns. Beyond beauty, understanding the rules that drive these self-assembling patterns could help us build complex structures in new ways.
“Physics is a strange science, because its mandate is everything. Everything!” adds Morris. “If there’s something left unexplained then it’s our job to go in there and figure out what the physics of that thing is.”
It may seem like a small thing to leave unexplained, but icicles aren’t just smooth inverted cones of ice. They actually have regular bumps that form as they grow. How these bumps form and the reason they are so regular are a mystery.
Morris grows icicles under controlled conditions in his lab to try to understand the physics of their formation.
“We know everything about the shape of the icicle,” says Morris. “We know everything about its growth: the flow rate, the temperature, the water, the concentration of the water, the humidity, the state of motion of the air.”
Morris digitally reconstructs the three-dimensional shape of the icicle over time as it grows. Using a 3D printer, he can even print a plastic replica of the icicle at any snapshot in time.
The goal is to understand the rules that underlie the complex and ordered formations found in nature. Knowing how they work would enable researchers to engineer self-organization.
“The place where you see self-organization most clearly is in biology: you see an animal go from an egg to a fish, and each little part seems to know what to do to organize itself,” says Morris. “There’s no blueprint of the fish that the fish is following.”
The shapes that emerge spontaneously come from a dynamic process of growing, folding, crumpling, cracking, wrinkling, branching, flowing and other kinds of morphological development. These processes can be seen repeated in many systems, but there is nothing written into the genetic code directing them to unfold as they do.
“You can imagine that if we really understood this kind of self-organized process, we could do this, too,” says Morris. “We could build machines that built themselves, or processes or materials without us having to go in there and template every little bit.”
Today’s electronics rely entirely on a human plan, where every element is mapped out in advance and precisely placed one at a time in a factory.
“Imagine making a processor where you just dump all the components into a pot and heat it up or whatever, and like a fish it just builds itself,” says Morris. “That would be an amazing piece of technology. And that would be a self-organized complex system.”
Inspired by nature, understanding the physics behind emergent patterns could be the key to tomorrow’s self-assembling technologies.