Why is Abishegam / Thirumanjanam performed?

This Blog throws some light on the doubts I've. For which I got some answers from my Father in law, Sri. Parthasarathy. If there are more doubts, pls post. I'l try to find some answers. These details are very interesting as we delve deeper. 

Why is Thirumanjanam/ Abishegam performed? Is there any scientific significance attributed to it? 

"Abishekam", as mentioned, is the term used with reference to saivaite formalities. For Vaishnavites, it is "Thirumanjanam". The deities, very importantly made of "Nava pashana" like the one of Lord Muruga in Palani and others made of "pancha lokha" are applied with special preparations mainly to extract the medicinal benefits of such vigrahas. 

Nava Pashana is believed to be an amalgam of nine minerals – Veeram, Pooram, Rasam, Jathilingam, Kandagam(Sulphur), Gauri Pasanam, Vellai Pasanam, Mridharsingh and Silasat

Before applying items like Milk, Fruit-mix, Honey etc, the statues are cleaned with oil, soap-nut, turmeric etc. Then the application of eatable items will render transfer of Nava pashana or the metallic  flavour into the applied items. These items are later given to the devotees as prasadam and consuming the same with medicinal particles of the statues, will add strength to our body and will cleanse and clear any in-built deficiencies. This secrecy of science is not openly conveyed to people, lest, they might think"Ho! only that!".

 

One other lateral concept is that the metal and stone statues have to be kept cooled regularly -- even daily -- in order to suppress the physical phenomenon of "expansion of solids", which might deform or crack the structure. Abishekam will keep the structure at optimal temperature.

 

The third and commonly seen concept is to treat the deity as our child and bathe it and adorn it with vasthram and flowers, to show our love, as you have rightly mentioned  Most of the Alwars have treated the Lord Narayana as child and rendered pasurams of conducting bathing (Neerattam), which are sung in the temple at the time of performing Thirumanjanam.