If you are using some concept to model to some parts of the physical reality, as attempt to explain WHAT they are and HOW they work, then yes, they are just words.
But the Scientific Method also required that the models to any hypothesis, must be tested. Such tests would
(A) either verify & validate the model as being probable,
(B) or refute & invalidate the model as being improbable.
Such tests would be observations of evidence or experiments, that should provide information about the evidence or experiments, known as data. Data, like evidence and test results of experiments, are observations as well.
Such tests and observations can weed out falsifiable hypotheses that are either weak & tentative or incorrect, in which case, these hypotheses would either reworked & amended with updated model (which the updated models would have to be tested again), or discarded and not proceed in further enquiring or research.
If the tests were successful, then it might proceed to the next step, by submitting a hypothesis along with all observational data, for Peer Review, or they may continue on more researches and more testings.
That’s the only way to determine if concepts are valid with reality or not, testing the concept. If tested true, scientifically, then the “concept” would be validate.
The Cartesian system of direction only work on Earth, where the needle of compass would point north, because of the polarity of the Earth‘s magnetic fields, are inducted from the two magnetic poles. So when you reach the (magnetic) South Pole, there are no south of the South Pole.
The thing is, Earth is what it is, and you cannot venture south, to do so, you would be travelling away from the South Pole.
To use the Earth’s South Pole as analogy, as a comparison with the universe, is to logically propose that everything exist in the universe there are no outside of the Universe, just as there are South Pole outside of the Earth.
Now, I generally dislike using analogies, because it can be often misunderstood, because the person or reader can be confused, but the real problems with using analogies when they are improperly applied, hence misused.
You talk of Southern Cross constellation, or the Crux. It does guide navigators to where the South Pole is, however the closest you are to the South Pole, the less helpful it is. If do end up at the South Pole, you won’t find the constellation directly overhead of you, as the Southern Cross is actually located around 60 degree above the South Pole at all times.
