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Thursday, July 10, 2008

Shining head


Stick a pin with a polished head into a cork cut in half lengthways and fix some celluloid on it to protect your eyes. If you look at the tiny light reflection from the head of the pin under a bright lamp, while holding it right up to the eye, it appears as a plate- sized circle of light. A hair stuck onto the moistened celluloid is seen magnified to the width of a finger in the circle of light.

The head of the pin behaves like a small convex mirror. The light, which hits it, is spread out on reflection, and irradiates a correspondingly large field on the retina of the eye.

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