Flocks of birds defy one of physics' fundamental laws

The Dresden Physicists’ Clever Trick

The researchers’ trick consists of assigning each bird in the mathematical model an additional, artificial partner. This does not exist in nature. In the calculations, however, it ensures that the movements of the flock can be described using known physical methods.

Biophysicist Ricard Alert describes it this way: "To precisely simulate the birds’ movements, we describe the dynamic ‘bird swarm’ system using established methods. The elegant solution: An additional bird is artificially placed in front of each bird, oriented exactly in the opposite direction."

These additional "counter-birds" exist only in the model. However, they make it possible to calculate the movements of such systems using established methods of physics. This allows researchers to draw on many proven tools that were previously unusable for such systems.

The research opens a new door. "The exciting question now is whether Newtonian exceptions lead to entirely new forms of collective quantum behavior. We still know very little about this. That is precisely what makes the topic so exciting," says Moessner.