The extraordinary flying ability of dandelion seeds is possible thanks to a flying mechanism that has not been spotted before in nature.
The discovery, which confirms the plant among the natural world’s best fliers, shows that movement of air around and within its parachute-shaped bundle of bristles enables seeds to travel great distances - often a mile or more, kept afloat entirely by the breeze.
Researchers from the University of Edinburgh carried out experiments to better understand why dandelion seeds fly so well, despite their parachute structure being largely made up of empty space. A parachute with holes doesn't sound very promising, does it? But their study - published in Nature - revealed that a ring-shaped air bubble forms as air moves through the bristles, enhancing the drag that slows each seed’s descent to the ground.
This newly found form of air bubble - which they are calling a 'separated vortex ring' - is physically detached from the bristles and is stabilized by air flowing through it.
The amount of air flowing through, which is critical for keeping the bubble stable and directly above the seed in flight, is precisely controlled by the spacing of the bristles. This flight mechanism of the bristly parachute underpins the seeds’ steady flight. It is four times more efficient than a conventional parachute design, according to the study.
The study was led by Dr Cathal Cummins, who said: “Taking a closer look at the ingenious structures in nature - like the dandelion’s parachute - can reveal novel insights. We found a natural solution for flight that minimizes the material and energy costs, which can be applied to engineering of sustainable technology.” That’s potentially very good news.