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Lighting a lantern

posted Nov 29, 2014, 7:32 AM by ranmini@charliesresearch.com   [ updated Dec 2, 2014, 10:08 AM ]
The full moon day of the month of May is considered the day Lord Buddha was born, obtained enlightenment and achieved Nibbana, It is customary for the kids of Buddhist children all over the world to light lanterns at night. Here is a special Wesak lantern with dancing spots of light. It would be real fun to make it.

Take a circular piece of thick paper. Draw a spiral as shown in dotted lines. Then pierce the centre with a pin and pass a piece of thread and tie a knot to prevent it slipping out. When you pull by the thread the spiral will open out as shown on the right, Hang this spiral over a hot body such as a flame, iron or a bulb. Observe what happens.

There is a method of heat transfer called ‘convection’. When the air gets heated up they rise upwards. These are called convection currents.  The turning of the spiral, you may have observed by now, is due to these hot air currents.

If you make the spiral turn inside a lantern, you can get various designs. Better than a paper spiral you can use an aluminum can or the bottom part of a plastic bottle.

You must mark the base of the can as shown in Fig.2 Then cut along the form lines leaving a circle at the centre. Inserting a knife blade through the cuts lift the shaded portions so that the parts may bend along the dotted lines. Make a hole at the centre of the circle to hang the can with a thread, Cut or punch small openings on the cylinder with a nail according to a design of your own.

If the can is now placed above a heat source such as a flame or a bulb it should go on turning due to the convection currents.  Here is the finished product of Nelly. As the cylinder turns, Lights will move on the lantern according to your design.
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