The Venus flytrap (Dionaea muscipula) was once described by Charles Darwin as “one of the most wonderful [plants] in the world”.
Consisting of two lobes that attach together to form a kind of jaw, the inner surface of each lobe contains so-called “trigger” hairs that cause the trap to rapidly shut if bended by a unsuspectingly insect.
When a hair is stimulated an electrical “action potential” swiftly spreads through the leaf in less than a second, activating the plant’s motor cells.
To study this in more detail, researchers in Italy, Sweden and the US attached an organic-based multielectrode array to the plant’s lobes. They found that once stimulated, the signal spreads radially at a constant speed away from the site but along no specific direction.
Yet the trap only fully closes if the hairs are stimulated twice within 20 to 30 seconds, a move that saves the plant energy if the hair is bent by something other than potential prey.
The team found that the second action potential helped to accelerate the closure of the trap. Eleni Stavrinidou, from Linköping University, Sweden, says that the work opens the “possibilities for new discoveries”.
Sound of the stars
“Twinkle, Twinkle, Little Star” is a popular English lullaby with the lyrics taken from an 19th century poem by Jane Taylor.
Stars appear to twinkle thanks to the atmospheric effects of light reaching Earth, but they also have an innate “twinkle” that is caused by the rippling waves of gas on a star’s surface.
Researchers in the US and UK have now carried out computer simulations of these rippling waves and converted them into sound waves, allowing listeners to hear both what the insides of stars and the “twinkling” should sound like.
The researchers describe the sounds emerging from the core of a large star as “a low echo reverberating through an empty room” while the waves at the surface of a medium-sized star “conjure images of a persistent hum through a windswept terrain”.
For a bit of fun, the researchers also simulated passing “Twinkle, Twinkle, Little Star” through the core of stars of varying sizes to see how the music changed. The result is rather eerie and haunting.
And finally, while it is known that falling cats always manage to land on their feet, as this article in Scientific American points out, they can also survive falling from a great height.