@concrete_baby Today, I learned that Star Trek ALSO has a galactic barrier. Not hear even, I was catching up on Discovery earlier. So now I am coming across Star Trek's galactic barrier twice, for the first time, on the same day. (Though, I must have seen it referenced on TOS at a some point.)
According to Memory Alpha, the barrier appears in at least three TOS episodes: "Where No Man Has Gone Before", "By Any Other Name", and "Is There in Truth No Beauty?"
@concrete_baby I swear I have seen all of TOS multiple times, but it has all faded. Mean while, the first thing I thought of was the galactic barrier in Star Wars canon, which seems less out of place, because, you know, space wizards.