How Dewis Formed?
A lot has been written about dew. For a long, it has been misunderstood. It appears a simple phenomenon of nature.
About 200 years ago, during Aristotle’s time, it was a belief that like rain dew “fell”. In actuality, it does not fall. The most common site of dew is the leaves of plants. There have been many wrong ideas about dew.
We know that air holds some moisture. The warm air can hold still more water vapor than cold air or come in contact with a cool surface some air gets condensed. The moisture assumes the form of drops. These are dew drops.
The cool surface has cool down to a certain temperature, so as to form dew drops. That point is called “the dew point”. Now we take some water in a glass or some metal container with a polished surface and observe that no dew collects on the surface. Now we put some ice into this water; dew may not form even new. After some time, when the temperature of the water has gone down to a certain point dew drops collect on the outside surface. In nature, when warm air is laden with moisture, it comes into contact with the cool surface of grasses or plants. Due to condensation dewdrops are formed. The ground or footpaths which have not yet cooled to the extent the plants have cooled, no dew is formed on them.
We know that the dew seen on plants in the morning is not mostly dew. In reality, in some cases, the moisture comes out through the pores of the leaves. It is a system of plants irrigation
Process for supplying the leaves with water from the sort. This action starts during day time so that the leaf surface should be able to withstand the hot Sun. The process continues at night but there is less evaporation, and thus the droplets shown on the leaf surface in the morning.
In some regions in the world, enough dew is deposited every night and collected in dew ponds for use as a water supply for cattle.