It's just about Thanksgiving here in the US; a special time during which we count our blessings. And this year, Tangents is giving you an extra thing to be thankful for: Stefan's our special guest! 

Our long lost co-host returns to talk to us about wings: birds love to use 'em, people love to eat 'em, and planes need them too, I guess. Sit around the table with us, won't you, as we pass out some heaping helpings of science knowledge. Pass the gravy!

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While you're at it, check out the Tangents crew on Twitter: Ceri: @ceriley Sam: @im_sam_schultz Hank: @hankgreen

[Trivia Question]

Number of bird wings in the Burke Museum 

https://www.burkemuseum.org/collections-and-research/biology/ornithology

https://www.audubon.org/news/behind-scenes-worlds-largest-bird-wing-collection

https://www.burkemuseum.org/collections-and-research/biology/ornithology/collections-database/results.php?l=20&o=0&n=40653&m=32557&f=&g=&s=17h%7EIymyNd1yIp&w=PfHdywfPYczv2Y01KbF0&wo=PHdywPYjdyhNdQIY1KbF

[Fact Off]

Club-winged manakins use wing feathers to chirp/sing

Video & audio: https://www.youtube.com/watch?v=tSHjhCN6NC0

Audio-only clips: https://ebird.org/species/clwman1

Picture of feathers: https://commons.wikimedia.org/wiki/File:PipraWing.jpg

https://news.cornell.edu/stories/2005/07/rare-south-american-bird-sings-its-feathers-attract-mate-cornell-researcher-finds

https://www.allaboutbirds.org/news/singing-with-his-wings-the-club-winged-manakins-display/

https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3440988/

[Ask the Science Couch]

Planes flying upside down

https://www1.grc.nasa.gov/beginners-guide-to-aeronautics/what-is-lift/

https://www.popsci.com/flying-upside-down-physics/

https://www.flyingmag.com/why-can-airplanes-fly-upside-down/

https://howthingsfly.si.edu/ask-an-explainer/how-do-planes-fly-upside-down

[Butt One More Thing]

Airplane and wing butt lines

http://www.aerospaceweb.org/question/design/q0289.shtml

https://www.aircraftsystemstech.com/p/location-numbering-systems-even-on.html

https://aviation.stackexchange.com/questions/72611/what-is-the-difference-between-a-wing-station-and-wing-buttock-line

http://www.techdrawingtools.com/24/l2402.htm