Recent content by hobboy

  1. H

    Cosmology Diff between Ryden's two 'Introduction to Cosmology' books?

    Barbara Ryden seems to have two Cosmology books, her one https://www.amazon.com/dp/0805389121/?tag=pfamazon01-20 and one https://www.amazon.com/dp/129203971X/?tag=pfamazon01-20. I haven't been able to find any differences between the books online - the 2013 book doesn't seem to be a new edition...