Mystery of Krishna's Siphon | English
Channel: Arvind Gupta
Date: 2016-10-01

In this brass cup sits Vasudeva with his son Lord Krishna seated in his lap. There is a hole in the base of this cup. When we fill some water in the cup the water does not drain out. But as we keep adding more water, the water ONLY drains when its level reaches Krishna’s foot. Here you can see water being drained from the hole below the cup. Once it starts, the whole water drains out from the cup.
 
We will try and solve the mystery behind this cup – through a simple science experiment. For this we will need a big CD box, bottle, bendable straw, glue and scissors. First make a big hole in the base of the jar. Its shape should be as shown. The big hole has a small notch. Cut the bottle in half and make a small notch as shown. The bottle must fit tightly in the big jar. Also the bottle notch should match the notch in the base of the jar. On inverting the jar and bottle will look like this. Seal the joint with rubber glue to prevent any leakage of water. Then cut a bend straw as shown and glue it on the notch as shown. Glue this joint too. Wait for a while for the glue to dry. Extend the bent straw by pulling it. Then bend the straw and insert it in the bottle as shown. The model is now ready for experimenting. Stick a picture of Krishna so that his feet reach the top of the bent straw. Now add colored water to the jar. Keep adding water until its level just reaches the bend in the straw. Once this level is reaches water will drain out of the straw because of siphon. This experiment will help you understand the principle behind the mysterious Krishna’s Cup.

This work is supported by IUCAA (www.iucaa.in) and TATA Trust (http://www.tatatrusts.org/) and (www.tata.com/aboutus/sub_index/Tata-trusts)

TATA Trust: Education is one of the key focus areas for Tata Trusts, aiming towards enabling access of quality education to the underprivileged population in India. To facilitate quality in teaching and learning of Science education through workshops, capacity building and resource creation, Tata Trusts have been supporting Muktangan Vigyan Shodhika (MVS), IUCAA's Children’s Science Centre, since inception. To know more about other initiatives of Tata Trusts, please visit www.tatatrusts.org

Credits:,Ashok Rupner, Manish Jain, Pradnya Pujari, Shivaji Mane, Jyoti Hiremath, Arvind Gupta, Vidula Mhaiskar