1. Shivalinga is based on a circular base known as Peedam. This is found in all temples. But lots of interpretations were made based on this without realizing the original truth. It is a holy symbol of Lord Shiva.
2. Shivalinga is not just based one some Hindu concept. It was referred as 'Prayapas' by Romans and later the lingams were found in the archaeological findings in Babylon. More were found during excavation of Harappa and Mohan-ja-daro.
3. Shivalinga consists of three parts. The Bottom, Middle and Top part. Bottom part is four sided and it is at the ground level. Middle part is called as Pedestal which is 8 sided and the Top part is being worshiped by us. As per rituals, Brahma is at the bottom, Vishnu is at the middle part and Shiva is on the top.
4. The lingam also shows the creation and destruction power of Lord Shiva. But most of them make their own imaginary stories based on this lingam.
5. Swami Vivekananda himself has said Lingam as symbol of Brahman. Most of the researchers have confessed this is not some imaginary invention.
6. There is even some science behind Sivalinga. The lingam is represented to be a Cosmic Egg. A Danish scientist Neils Bohr says Molecules are made of Atoms which are made of Proton, Neutron and Electron and they are the essential parts in composition of Sivalingam.
7. As those days, people never use more technical terms they have used words like Lingam, Vishnu, Brahmaa, Shakthi, Sarappa and so on.
