Are we alone in the universe?

An interesting question ..... lets do some calculations.

There are approximately  17 Billion Earth sized worlds in our galaxy. 

Note that’s in our galaxy, in the universe there are estimated to be 100 to 200 billion galaxies. Actually data from the new telescopes in space puts this estimate much higher at 500 billion galaxies.

Being conservative let’s assume that only 1% of those planets is in its star systems habitable zone i.e. the correct distance away from the star to encourage life. (Bearing in mind we are considering life as we know it) that's 170,000,000 worlds (170 million).

So let’s be skeptical and say that only 1% of those planets have actually developed life.  That’s 1,700,000 (1.7 million) Earth sized worlds with life on them.

Continuing to be pessimistic let’s assume that only 1% of those Earth sized worlds have developed complex life forms like animal’s.  That’s 17,000 worlds with animal life form or similar.

Carrying on being skeptically pessimistic let’s say that only on 1% of those planets have the life forms evolved to a level similar to humans. That’s 170 worlds with civilization at a stage similar to ours in our galaxy.

Let’s be optimistic now and assume that on 1% of those 170 planets the evolution of the intelligent species has gone to a higher level than ours.  That’s 1.7 worlds where the intelligent civilization has probably mastered space travel.

1.7 worlds …. Well that’s not many

But hang on we are only talking about our galaxy.  Lets go back to the amount of Galaxies in the universe low estimates are 100 to 200 billion galaxies (Current estimates are higher and in the 500 billion region)

So 1.7 worlds multiplied by (lets go low) 100 billion galaxies.

That’s  28,900,000,000,000 worlds probably with life at a higher level than ours.

Let me put that into words, That’s 28.9 Trillion.

28.9 Trillion with life at a higher level than ours.

Lets be hopelessly pessimistic and say that only .1% have survived (That’s point 1 of a percent)

That’s still 28,900,000,000 worlds (28.9 billion) with a life form probably at a higher level to ours.

OK ever the pessimist let’s say that only .01% (That’s point 01 of a percent) have really developed space travel.

That’s still 2,890,000 worlds (2.8 million)  in the universe with a life form higher than ours that has developed space travel.

But back to our little galaxy

170 worlds with civilization at a stage similar to ours in our galaxy.

Still think we are alone?

The problem is the universe is so vast the human mind cannot comprehend it.

Why haven't we received communication from them? 

Can we understand what an ant is saying?  Can an ant understand us?

But we can look at an anthill and say "hey that's pretty clever how they build that".  

Do we try and communicate with the ants even though we know they are there?

The problem with humans is we are so filled with our own self importance and blinkered by religion we fail to perceive we are merely Ants in the big scheme of things.