Chapter 8 2.5 From quantitative change to qualitative change

A tank full of water.When you unplug the sink, the water starts to stir, creating a vortex.The vortex develops into a vortex, growing like life.After a while, the vortex expanded from the water surface to the bottom of the tank, driving the water in the entire tank.The ever-changing waterfall of water molecules swirls in the tornado, changing the shape of the vortex every moment.And the vortex remained unchanged, dancing on the verge of collapse. "We are not stagnant dead things, but self-perpetuating patterns," wrote Norbert Wiener. The sink was empty and all the water was drained through the whirlpool.Where does the whirlpool pattern go when the full tank is drained from the tank to the drain?Where does this pattern come from?

No matter when we pull the plug, the vortex will always appear.A vortex is an emergent thing—like a swarm, its energy and structure are contained in the swarm rather than in the energy and properties of individual water molecules.No matter how well you know the chemical signature of H2O (the molecular formula for water), it won't tell you anything about swirls.Like all emergent things, the properties of the vortex derive from the presence of a large number of other entities; in the example given earlier, a tank full of water molecules.A drop of water is not enough to create a vortex, and a handful of sand is not enough to cause a dune to collapse.The emergence of things mostly depends on a certain number of individuals, a group, a collective, a gang, or more.

Quantity can make a substantial difference.A single grain of sand cannot cause a dune to collapse, but once enough sand accumulates, a dune will appear, which in turn can cause a sand avalanche.Some physical properties, such as temperature, also depend on the collective behavior of molecules.A lone molecule in space has no exact temperature.Temperature should be considered as a group characteristic of a certain number of molecules.Although temperature is also an emergent feature, it can still be measured with certainty and even predictable.It is real. The scientific community has long recognized that there are major differences in the behavior of large numbers of individuals versus small numbers of individuals.Clustered individuals conceive the complexity necessary to produce emergent things.As the number of members increases, the possible interactions between two or more members increase exponentially.When the degree of connectivity is high and the number of members is large, the dynamic nature of group behavior arises. — Quantitative change leads to qualitative change.