On Earth, the cardinal directions are straightforward. The arrow on a compass points to the nearest magnetic pole. You can then use it to travel anywhere on Earth.
In space, the idea of anything being “central” enough to be used as a “North” (since the universe has no center) or being fixated enough to not somehow pose issues is more convoluted.
If you were a pioneer of space exploration, what would your “North” be?
The “prime meridian” is the line through the black holes at the centers of the Milky Way and Andromeda, and the “equator” is the galactic plane.
If they’re intergalactic explorers, why would they care about the plane of our ordinary galaxy?
Why would they choose those 2 galaxies for a meridian?
Galactic coordinates are easy. OP asked about inter galactic.
Because it’s a convenient navigational system. If everything outside your home is arbitrary, may as well keep using landmarks you’re family with.
LOL it took almost 200 years for humans to agree to use Greenwich as the prime meridian of Earth.
What makes you think intergalactic travelers will adopt our galaxy as the point of reference?
For the same reason GMT became the standard: Somebody has to make the clocks. Space is pretty big, but if I had to bet money, I would wager that the first intergalactic travelers would start here, where the people are, and they would start with here as their point of reference.
Why would you assume humans are the first intergalactic travelers? The universe is 14 billion years old.
Because as big as space is, time is bigger. Humans have existed for only the most recent nanosecond, and we’re only just figuring out how to leave this rock. We’re either going to figure out intergalactic space travel, or we might just obliterate ourselves and kill all life on the planet.
Crossing paths with another intergalactic species would be like if two different people each threw a grain of sand into the air in any desert or beach on earth at some point in the last 10,000 years, and the two grains of sand collide.
If we do find intelligent life out there, it will probably be because we have developed some intergalactic broadcast signal, and whatever comes for us might share their star maps or they might just be looking for a snack. Either way, it would take them thousands of years to hear our signal and get to us.
The post says I’m the boss, so as a human I’m going to pick my own home galaxy as the reference. Alien species would have their own coordinate systems but it’s not that hard to convert between them, or to specify which reference you’re using. We’ll already be converting between planetary/system/galactic/intergalactic coordinate systems all the time so it’s not much harder to account for a few more.
We will make them, through the might of the Helldivers.