Most of the world pretty much standardized on life + 70... for everything published around 1980s and later. We just made a bunch of shit up arbitrarily for thin

Most of the world pretty much standardized on life + 70... for everything published around 1980s and later. We just made a bunch of shit up arbitrarily for things published before that conclusion was reached. Some countries backdate life + 70 to works published before life + 70 was a thing. In the US it's 95 years after publication for anything published before 1978 (and life + 70 for anything published in or after 1978). So, Orwell remains under copyright in the US because his works were published <95 years ago, before life + 70 started applying. For a hypothetical author that published something on January 1st 1978 and died the same year, that work would enter the public domain in 2048. If the same work was published just a day earlier, it'd enter public domain in 2072. Another conclusion one can reach from this is that life + 70 rule itself is under 70 years old, so no work actually entered public domain that way, and in the US no work will enter public domain that way for the next 25 years.