Last fall at Elder College (a series of courses run at North Island College) I attended a great class on our Solar System.  The teacher is a retired professor who taught at Stanford.  Great guy who is enthusiastic about teaching.  Loved his class and even bored my kids and grand kids with a short lesson (which they shrugged through).

This term I took his far more detailed and difficult course on Cosmology or the history of the Universe.  Start with the big bang and move from there.  How stars are formed and galaxies and lots of weird stuff like dark matter and dark energy.

24 senior students in the class and we are stunned.  Obviously too big a subject to pick up at the age of 70 but fascinating.  Einstein wrote about how space and gravity curves light which is why we can still see today with Hubble telescope remnants of the Big Bang 13.7 billion years back in time and distance.

Today we discussed black holes and Quasars.  (well discussed is relative, mostly Joel did the talking)  Black holes are thought to be massive stars that shrank due to gravity but unlike most stars did not blow up.  As they cooled slowly they became so dense that the gravity pulled in everything and was so strong photons (light) could not escape.  Hence why they are black.

Other stars are captured in a spiral of death around black holes and as they sped up they heated up and gave off a massive burst of energy.  A sort of a last SOS before they were sucked into the black hole.  We see those bursts as Quasars.

Fortunately for us we are on the very outer rim of the Milky Way Galaxy.  It is thought that there is a black hole at the center of our Galaxy, but we are far enough away that it will not suck us in for billions of years.  Granted I am 70 so probably not going to be a problem for me.

At the end of each class Joel offers aspirins.  It started as a joke but as we are walking away we shake our heads and tell each other that this is mind blowing (without LSD).