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.

Cosmology Lectures - NOT amateur radio

Most of this autumn I have been going to U3A lectures in Cambridge on cosmology. One of the advantages in Cambridge is we are surrounded by very learned people. On this course, there are many people who worked in the university.

One member of the audience had a Cambridge University professor as a friend. When he said he was attending a course on cosmology he retorted, "ah metaphysics".  Perhaps he is right!

Cosmology - NOT amateur radio

As part of my University of the Third Age lectures , I am attending a course on Cosmology. It is very interesting, but also very hard.

Like last year, I try to take away some aspect of what I have learnt. My overwhelming thought is "this cannot be right".  Yes, the explanations sound plausible, but we know so very little. My overriding thought is "in 100 years people will say, "did you really believe THAT?"".

It is very enjoyable just being able to learn for fun with no worries about exams  etc..

Next term, I am doing something quite different: the history of the Bank of England.

It is also nice being in Cambridge.

UPDATE 1855z:   It has been estimated that there are 60000000000 planets in the Milky Way galaxy alone that could support life.  There are billions of galaxies in the universe that we know of. So, it looks like somewhere out there there should be life. Mind boggling.