Distance, paralax and parsecs

Excellent tutorial, Brian.  I now understand how a Parsec is derived.  Can we have this in an Astronomy tutorial thread somewhere? We can then build on it with videos such as this?

https://www.youtube.com/watch?v=EIpEzZqkd9c another one for you Tej.

Thanks Brian, just watched it.  Very entertaining lecture.  Seems a bit cut up but I think justifiably as he tends to go off tangent very often.

OK so the other method of measuring more distance stars and galaxies are to find the standard candle, eg supernovas in other galaxies with an absolute magnitude.  We can measure distances to stars in our galaxy up to 1000 parsecs away using the geometric parallax method according to the first video.  Any further, the parallax angle is too small to calculate the distance.  Second video only tells us about the method of measuring the further distances but just wondering is the maths complicated?  Any videos like the first one that can explain it in maths, just thought I might have a go grasping it 🙂

The other element of his lecture says mathematically we're in a flat universe.  Concept sounds very logical to me but man its a depressing thought!  A closed universe would have been more desirable and comforting for me, because I like the thought of a universe recycling endlessy...but that's not what science is about, huh, not what we desire just what is a scientific likelihood.  Observation wise, I take it is not conclusive yet.

https://www.youtube.com/watch?v=2pGPxKjXRVc . Tej, as requested.