What paper went into that flap?

How would you make a single flap?

We're going to learn how to make one flap.

Well, there are other ways of making a flap.

I didn't have to try to flap my wings.

So that's the flap, and all the rest of the paper's left over.

It's very complicated, but it turns out they flap their wings very quickly.

And if I make the flap from the middle, it uses a full circle.

If I put the flap on the edge, it uses a half circle of paper.

Gains for developing countries hinged as much on their own liberalization as on the market opening made by trade partners.

And you can see there, it needs a quarter circle of paper to make a flap.

Above all, it concluded that the sustainability of ongoing reform programmes hinged on substantial investment in human and institutional capacity building.

So, no matter how I make a flap, it needs some part of a circular region of paper.

If I make the flap as skinny as possible, I get to the limit of the minimum amount of paper needed.

According to the Trade and Development Report 2004, the balance between national welfare and international integration hinged on an appropriate mix of market forces, policy space and collective action.

The U.N. you know, they took 20 years just to add a flap to a tent, but I think we have some more exciting things.

And from that stick figure, I somehow have to get to a folded shape that has a part for every bit of the subject, a flap for every leg.

And we tackle this problem by building giant, dynamically scaled model robot insects that would flap in giant pools of mineral oil where we could study the aerodynamic forces.

Well, if I unfold it and go back to the crease pattern, you can see that the upper left corner of that shape is the paper that went into the flap.

Take a square. Fold it in half, fold it in half, fold it again, until it gets long and narrow, and then we'll say at the end of that, that's a flap.

The EU must make it clear that it is ready to support Serbia and the region as a whole in realizing its European aspirations. European security is hinged on Serbian integration, just as Serbian aspirations hinge on the EU.

Whereas in the Third Committee the responsibilities of Vice Chairmen and Rapporteurs were distributed on the basis of the dates on which the Secretariat received notification of the candidates endorsed by the regional groupings, the practice in the other Main Committees hinged on the principle of rotation.

Whether Europe would avoid a deep depression hinged on whether it dealt properly with these two aspects of the crisis. But whether Europe as a whole avoids lost decades of economic growth still hangs in the balance, and depends on whether southern European governments can rapidly restore competitiveness.

Effective and timely delivery of United Nations assistance through its operational activities hinged squarely on the volume, availability and predictability of resources, and greater efficiency and coordination would not be sufficient to cope with the dual problem of increasing demand and decreasing resources, even though the donors believed that the main thing was to reform the delivery process and the resource mobilization mechanisms.

And it turns out that the insects flap their wings in a very clever way, at a very high angle of attack that creates a structure at the leading edge of the wing, a little tornado like structure called a leading edge vortex, and it's that vortex that actually enables the wings to make enough force for the animal to stay in the air.

PRINCETON Forty years ago, I stood with a few other students in a busy Oxford street handing out leaflets protesting the use of battery cages to hold hens. Most of those who took the leaflets did not know that their eggs came from hens kept in cages so small that even one bird the cages normally housed four would be unable to fully stretch and flap her wings.