For those interested in the cosmic distance ladder, David Butler has an excellent youtube series "How far away is it?", detailing the methods used to estimate d

For those interested in the cosmic distance ladder, David Butler has an excellent youtube series "How far away is it?", detailing the methods used to estimate distance along the cosmic distance ladder, the history, and examples. I highly recommend. https://www.youtube.com/playlist?list=PLpH1IDQEoE8QWWTnWG5cK4ePCqg9W2608 https://www.youtube.com/playlist?list=PLpH1IDQEoE8QWWTnWG5cK...