This is bird-note.

When birds take to the air, what actually lets them leave the ground and fly?

The secret to bird's flight starts with the shape of their wings.

They're curved in a way that causes air to flow more slowly under the wing than above

it.

It creates an area of low pressure just above the wing that pulls the bird up into the

sky, a force called lift.

Airplane wings are curved in a similar way.

Called an airfoil, these curved structures create lift as air flows across them.

Unlike an airplane, bird wings don't stay in place.

They flap.

That lets birds push their way into the air from a dead stop, unlike planes which need a long

runway.

On the upstroke of a wing flap, birds fold their wings inward, reducing drag on the wing.

They can also let air slip through the gaps in their feathers as they raise their wings,

making the upstroke even more efficient.

The details of bird flight have influenced many technologies, from new types of aircraft

to the design of wind turbines.

Who knows what birds will inspire next.

For bird-note, I'm Michael Stein.