The worlds/Universes

Let us understand "Universe" for a moment here. The vedas say that each universe is egg-shaped and that there are many such universes. Each universe is situated above one of Seshnag's head. Seshnag has countless heads, and therefore there are countless universes. On a jovial side, one may wonder what would happen if Seshnag were to catch a cold and sneeze - will be universes tremble and shake? Well, the Lord has thought a way for that also - because he realized the such a huge snake when he even breathes the worlds will go up and down. so, just like we have shock absorbers in our cars, He placed the seven avarna waters as the padding on Seshnag's head, and then placed the universes on them. All these universes together are called the "changing worlds". It implies that the only thing constant and ever assured in these worlds is change.

The Lord, on the other extreme has also created a "permanent world" in which "changes" do not happen. The Lord himself is referred to as "Avikara" - one without change. This permanent world is called Sri Vaikuntha (the land of no diminishment).

Returning to the discussion on the tri-gunas, the changing worlds (all thousands of them) and everything in them are composed of the three gunas - sattva, rajas, and tamas. The permanent world and whatever it contains (all matter, all people, all everything) are composed of "shudda-sattva". The reason for calling it "shudda-sattva" is to distinguish it from the "mishra-sattva" (mixed sattva) that is present in the changing worlds.