Some amazing numbers - NOT amateur radio

Yesterday was the last lecture on cosmology as part of my U3A sessions in Cambridge. We heard some truly staggering numbers which I shall share here.

• There are at least 100000000000 (100 billion) galaxies in the observable universe.
• Each galaxy contains at least 100s of billions of stars.
• The universe is mostly empty space.
• 5% of the universe is atomic matter. The rest is mostly dark matter or dark energy. We do not know what these are.
• Many stars have planetary systems.
• The universe is at least 41 billion light years across.

It was an interesting series of lectures, but my "take away" thought is just how little we really know.  Many of the theories fit, but many are incomplete.  Some theories involve multiple universes.  We really know nothing. Humans are a speck.

Back in the 1960s there was a series of books by Eric von Daniken. His basic theory (I seem to recall) was religious events were the result of visits from other worlds of beings different from us. Events at those times long ago were interpreted as supernatural. Remember, we still believed in witches just a few centuries ago!   Now, I am not saying he was right, but it an interesting thought.

What I do know, is that whatever we think now is most probably wrong. It is our interpretation of things by our (small) human brains. The truth is we do not know. All we can do is live kindly. Most religions have kindness to others at their hearts.