For tech books, most old books have been superseded by modern versions. The original may be interesting for a history of science point of view, to understand ho

For tech books, most old books have been superseded by modern versions. The original may be interesting for a history of science point of view, to understand how each idea got slowly refined to get to the current state, but the modern books have a destilled version of the old results. IIRC the original Einsten paper about relativity doens't use Minkowski spaces, but all modern explanaions use it because it makes everything more clear. About books it's more difficult. It's interesting to read the discussion by Hofstadter about the translation of "Gödel, Escher, Bach: An Eternal Golden Braid" The book is full of subtle details that can be overlocked or broken in the translation. I guess translating Borges from Spanish is very difficult too. IIRC someone bought the rights and made horrible translation to ¿German? and they are waiting to make new translations.