Q. How does floating diya work in water?

When compared to the cohesive forces between oil molecules the adhesive forces between the wick molecules are stronger creating a pressure gradient that causes the liquid to rise in defiance of gravity. The diya oil and cotton wick stand for the element. Purchases of diyas are encouraged on Ashwin Purnima the full moon day before Diwali by 15 days as per Indian custom. Once the diyas have been immersed in water until they are completely submerged they are prepared for the Diwali ceremony.