When
bacteria swim at just the right speed, swirling vortices emerge. As those
patterns disintegrate into chaos, physicists detect a telling mathematical
signature.
In
physical systems, turbulence emerges when the smooth flow of a liquid or gas is
disrupted, producing unpredictable swirls like those in billowing smoke,
foaming surf, and a stomach-dropping flight. Try as they might, scientists
still cannot predict precisely how smoke, water, air, or any other substance
will move about during turbulence.
Something
similar appears to happen within certain biological systems. Recently,
scientists have discovered a turbulence-like dynamic emerging from what they
call active fluids, such as a dense mass of swimming bacteria or a collection
of movement-generating proteins suspended in liquid. Unlike a drop of water,
these active fluids move on their own power. The biological turbulence they
generate therefore differs in some significant ways from the physical
phenomenon, and the relationship between these two types of turbulence remains
controversial and poorly understood.
The
discovery bridges the two by showing that as it emerges and propagates,
turbulence follows the same pattern in masses of swimming bacteria as it does
in air, water, or any other physical system.
See:
Posted by Dr. Tim Sandle