If we have to traverse the Cosmos, the first thing we need is a Cosmic Coordinate System (technically called Celestial Coordinate / Reference System). We need this to pinpoint the exact (or approximate) point in space where we have to go. This is similar to (but a much more advanced version of) the Geographic Coordinate System which we use here on Earth. The Geographic Coordinate System is the system of Latitude, Longitude and Elevation (a three dimensional Cartesian Coordinate system). But for Cosmic mapping, we need to go beyond this. We need a three dimensional Spherical or Rectangular Coordinate system for pinpointing the exact location of a specific star or planet. In addition, we need a Geographic Coordinate System (similar to Earth’s) for each star’s or planet’s surface.
The current Celestial Reference System, adopted by the International Astronomer’s Union (IAU), is the International Celestial Reference System (ICRS). It uses the barycenter of our Solar System to define the positions of various planets and other astronomical objects.
It is good enough for observing and documenting various astronomical objects from the Earth. But, is it good enough for the purpose of interstellar travel? For that, we need a complex mathematical mapping, which takes into account the trajectories of different planets. Planets which are hurtling across at breakneck speeds.
Also, once we reach the limits of what we can observe from the Earth, we have to observe more from those points outward. Expanding (literally) our sphere of mapping. Like the explorers mapped the surface of the Earth, we have to map the entire Cosmos, bit by bit.
But, Is this even possible in an expanding Universe? Or are we being restricted by our imagination, by trying to extrapolate our primitive Geographical Coordinate System to the Cosmos? Is there a more elegant and holistic (conceptual or mathematical) solution which will help us map the Universe in a more efficient way?
Could the answer lie in Quantum Entanglement? Two entangled particles separated by cosmic distances, communicate their change of state instantaneously to the other. How do they know the location of their counterpart to communicate their change of state? What is the science behind it? Tap into that technology and we may have our Cosmic Coordinate System (and a lot more goodies).