Flying is a huge privilege. Humans had to earn it through the technological advancements, while for some animals it came naturally. However, did you know that dandelions are among the natural world’s best fliers? In fact, their seed exhibit a form of flight that has not been seen before in nature, according to a new research from the University of Edinburg.
Dandelion is a flowering plant from the family Asteraceae. Dandelions are native to Eurasia and North America, but have been introduced to other places in the world. In fact, dandelions are iconic and very well-known for their seed spreading ability. When the flowering period is over, petals dry and fall off, while parachutes of the seeds open. These tiny white spheres, largely containing just air, become vehicles for the dispersal of seeds. They gracefully fly through the air great distances and not much wind is required due to a very light weight. Scientists estimate that a dandelion seed can travel for a kilometre or more propelled solely by wind power.
Parachute structure of dandelion seeds is largely made up of empty space, which always confused scientists – how can it fly so well? Scientists did a lot of simulations and experiments and found that when air is moving through the parachute bristles a ring-shaped air bubble is formed. It enhances drag and allows the seed to gently descend to the ground. This air bubble, named separated vortex ring by scientists, is precisely controlled by the air flowing through the bristles, which is controlled by the gap between them. In other words, mechanical properties of the parachute underpin the seeds’ steady flight. Scientists estimate that this parachute design is around four times more efficient than what is possible with conventional parachute.
Scientists go as far as calling the remarkable flying ability of the dandelion seed a form of flight that has not been seen before in nature. Designs of this funny parachute could actually inspire creation of ultra-small drones that could fly using very little energy. They could be used as various sensors – for example, to monitor air pollution. Dr Cathal Cummins, one of the authors of the study, 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 minimises the material and energy costs, which can be applied to engineering of sustainable technology”.
When you blow on a dandelion, take notice how long it takes for seeds to reach the ground. These tiny white parachutes are extremely efficient – seeds land so slowly that they can be picked up by the wind again and cover even more distance. It will be interesting to see if scientists will find a way to use this design for the advantage of human technology.
Source: University of Edinburg