nytvideo: The force generated by a flapping wing on the downstroke is about twice a bird’s weight http://nyti.ms/1AbW8iF

nytvideo: The force generated by a flapping wing on the downstroke is about twice a bird’s weight http://nyti.ms/1AbW8iF

tags: nyrpeä,

from: http://nyrpea.tumblr.com/post/114858085640