How Do Bird Wings Enable Efficient Flight Compared to Airplanes?

TL;DR

Bird wings utilize overlapping feathers that create a biomechanical check valve, reducing air resistance during flight. By angling their wings and performing elliptical sweeps, birds minimize surface area and generate both upward lift and downward thrust, allowing for more efficient flapping motion compared to airplane wings.

Transcript

[music] Hey it's me Destin welcome back to Smarter Every Day. So some of my favorite things to learn are those things that I've seen for several years and I've made a lot of observations and I kind of think I get it, you know. I mean, like really get it. And then I find out, I don't. So when I first saw what I'm about to show you, it blew my mind b... Read More

Key Insights

• 👱 Birds utilize feather overlapping to reduce air resistance during the down stroke, providing a firm boundary layer.
• 🪶 The delamination of feathers during the upstroke allows for decreased resistance and airflow between feathers.
• 😘 By performing elliptical sweeps and decreasing wing length during the back stroke, birds minimize surface area and resistance.
• 😘 Birds create low-pressure situations on top of their wings, providing upward lift through the pull-off of feathers.
• 😘 The angling of wing tips during the back stroke allows birds to provide downward thrust, resembling a vertical takeoff Harrier jet.
• 🤗 Birds open up their feathers on the back stroke to reduce air resistance, which can be observed as sunlight passing through.
• 🐦 Observations of bird flight have debunked the misconception that birds solely generate lift by pushing against high pressure underneath them.

Questions & Answers

Q: How do birds reduce resistance during flight?

Birds reduce resistance by overlapping feathers on the down stroke, allowing the wing to act as a check valve. They also perform elliptical sweeps and decrease wing length during the back stroke to minimize surface area and resistance.

Q: What is the significance of the low-pressure situation on the tops of bird wings?

The low-pressure situation on the tops of bird wings creates an upward lift by pulling feathers off the wing during the down stroke, effectively creating a low-pressure zone.

Q: How do birds provide downward thrust during the back stroke?

Birds can provide downward thrust during the back stroke by angling the tips of their wings, breaking the wing between secondary and primary feathers, and diverting the flow downward, similar to a vertical takeoff Harrier jet.

Q: How do birds reduce air resistance on the back stroke?

Birds reduce air resistance by opening up their feathers and allowing air flow between them during the back stroke, which can be observed as sunlight appearing between feathers.

Summary & Key Takeaways

• Birds have a biomechanical check valve system in their wings where feathers overlap during the down stroke and separate during the upstroke, reducing resistance.

• By performing elliptical sweeps with their wings, birds decrease the surface area and resistance during the back stroke.

• Birds also create low pressure on the top of their wings, assisting in flight by pulling feathers off the wing and providing upward lift.