I wonder if there’s some Sumerian wordplay that is lost because we don’t know the exact pronunciation. Maybe something in there has a homophone that we can’t know but that makes the joke work.
Of course, we’re probably also losing something in translation. Does the word translated as “see” actually mean “see”, or more like “sense” (and so might encompass hearing or scent)? What does “open” mean-- Could it, in this context, include lighting a lamp?
Dog is slang for a young guy looking to meet women. Also, your penis is referred to as your “third eye”. So, the joke is that a guy who’s looking to meet women comes into the bar and “complains” that he can’t see so he has an excuse to pull out his penis.
In the WBUR article, Dr. Gonzalo Rubio from Penn State suggested that the word for “bar” could mean tavern but also “a place for sex trade.” His point was that it also could be “a dog walks into a brothel.”
I once had a dream that I spoke to an ancient Sumerian about this joke. They said it was a reference to the (then common) belief that dogs won’t poop in the dark. They also said it’s funnier in the original Sumerian, but also it’s not a particularly good example of their culture’s humor.
Absent any actual ancient Sumerians to ask, I present this as the closest we’ll ever get to an explanation.
Wikipedia has the translation from the first person that translated it:
An explanation for the joke is offered in the OP’s article:
Or, if it’s a bar acting as a brothel, it could be that the dog enters the bar, but there’s no-one actually in the bar, so he opens a door to reveal what is going on behind closed doors.
See, there’s this cute little bar on the south side of Ur (take a left at the 25th century BCE), where they have a ten-for-one Happy Hour, starting when the shadow of the stick touches the rock, until you can’t see the stick.
Well, these Ammonites are playing cards, a heated game of Go Rat, and the Sumerians decide to start telling purposely bad jokes, louder and louder so the jerks will leave, and we only found out later that Chucko of Eridu carved one of the silliest ones for posterity. The funniest part is that centuries later, people are trying to figure out the stupid Bar Dog Joke.