Butterflies create jet propulsion with a clap of their wings
Feb 25,2021 - Last updated at Feb 25,2021
AFP photo
Agence France-Presse
PARIS The whimsical, wafting flight of butterflies may not give the impression of top aerodynamic performance, but recently published research suggests their large flexible wings could be perfectly designed to give them a burst of jet propulsion.
Scientists at Lund University in Sweden set out to verify a decades-old theory that insects clap their wings together, squeezing out the air between with such force that it thrusts them forward.
In their aerodynamic analysis of free-flying butterflies published in the journal Interface, they showed that the clap function does generate a jet of air propulsion.
Pfizer/BioNTech say vaccine effective against UK, SA Covid-19 variants
By AFP
By Stephane Orjollet and Kelly Macnamara
Paris, France - The vaccine made by Pfizer and BioNTech appears to retain its effectiveness against coronavirus mutations in worrying new variants that have emerged recently in Britain and South Africa, the firms said Thursday.
Several new variants - each with a cluster of genetic mutations have sparked fears over an increase in infectiousness as well as suggestions that the virus could begin to elude immune response, whether from prior infection or a vaccine.
Pfizer/BioNTech, which had previously said it was unlikely that the strain originally found in Britain could escape vaccine protection, said Thursday that early tests suggest their immunisation would be similarly protective against the variant in South Africa.