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walrus01today at 12:51 PM1 replyview on HN

As this is all very theoretical and silly I think the only viable option would be to define some spherical or cubic volume of space with an individual star at the center, and say your unique ID number 'owns' that section of space. Which would over a geological time scale move along with the star's movement within its galaxy and the universe as a whole.


Replies

antonvstoday at 1:44 PM

What about rotation, though? E.g. if you fix a coordinate system on Earth, then it rotates through the entire universe on a daily basis.

We might want to use something like the International Celestial Reference Frame (ICRF), which is designed to avoid rotation with respect to certain distant extragalactic objects.

You'd also need to take the expansion of the universe into account. You'd really need to start using comoving coordinates (https://en.wikipedia.org/wiki/Comoving_and_proper_distances)

It could make sense to sell spacetime worldtubes instead.

> geological time scale

Things appear to move slowly when viewed from the origin of the coordinate system, but unless you take steps to avoid it, like using comoving coordinates, then at great distances the motion of any given parcel would be enormous relative to local matter, easily exceeding the speed of light.