Hrumph! Punny hu-man "bags of mostly water"! You know not what universe is like. Hrumph! You only observe 3 dimentions! What you know!
You can't figure how many species are on your own planet - never mind how many planets there are. Next contact we make will instruct you as to where to go to be harvested....
Here's one attempt to calculate how many planets could contain intelligent life - the Drake Equation. Many of you know it already but here it is for those of you who don't....
Drake Equation.
By the way - who determines if life is intelligent or not? ...hopefully NOT my brother-in-law...
