Friday, 9 July 2010

Yet more penguin pictures!

These are official Royal Society photographs of the Festo penguins flying around the auditorium in the Royal Festival Hall the other week, and are the best photos I've seen so far.

Something I think is interesting is the penguins' wings. Look at the first photo, where it's flying from right to left (the wings are nearest the front.) The wings are pointing down, but also angled so the trailing edge is downwards. From this I deduce that these wings are on an upstroke, so that as the wing sweeps upwards, it drives the air backwards. I'm pretty sure this is how a real bird's wing works, too.

I draw attention to this because Jenny just assumed there was a little propeller somewhere, driving the thing through the air, but actually there isn't.

In the second photograph, showing also the ray, the nearer penguin's wings are pointing down but this time with the trailing edge level with the leading edge. The difference between these two photographs shows clearly that the flapping mechanism is rotating the wing so as to create forward thrust, and that's what I find so cool about these toys.

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