

But that’s the thing though. How can you determine the Earth as a reference point without knowing how it relates to other objects in space? “Here” is as useful a coordinated system as a fake absolute positioning system. “Here” is just your relation to other objects. If you don’t know what your relation to those objects is you can’t determine where “here” is, or the Earth for that matter. Whether it’s the machine or the person operating it, something or someone has to calculate where the Earth is in order to use it as a reference point.
If you are driving away from your friend at 20 mph, from your perspective they are moving away from you at 20 mph while you are the one that’s stationary. The only thing determining your location, or reference point, is your relation to each other.
But that’s the point that I’m trying to make. It’s probably my fault as I’m not very good at explaining things like this, and I’m not disagreeing with at all. I’m just saying that there is no way to have a machine or method of travel with a fixed point without knowing its relation to other objects. Just like you can’t know the trajectory of the Earth through space without knowing its relation to other objects. What I’m saying is that regardless of your “fixed point” you will have to do the same math, just in a different order depending on your point of reference. We are dealing with relatively here so the only variable that changes is your point of reference while the math stays the same.