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Comment by gku | Hacker News Reader

If you find this impressive, take a look at the 1.33 billion stars TSP solution provided by the same authors.

- Gaia DR2 (1,331,906,450 Stars): https://www.math.uwaterloo.ca/tsp/star/gaia2.html

> "The tour is at most 1.0038 times the length of a shortest-possible route."

But that presumably doesn't handle the relative motion of the stars, which makes the problem even trickier, since the distances will change as you travel, no? Or is my astronomy off base here?

I think your astronomy skills are correct, but if we have to worry about actual travel then you would also have to consider things like fuel capacity, refuel opportunities, the fact that you probably don't want to actually fly through a star but around it, etc.

I think it's still valid to have a distinction between travel logistics and having a route that's at least theoretically possible. I suppose what they've calculated would work with a star gate like system, but then I'm not sure what the point of having minimal distance would be.

The bar problem has its own issues. With that many bars some may close or new ones may appear during the time of the walk.

Isn't the flying around problem just "e" since it is so many orders of magnitude less than the distance between stars that for this calculation it is irrelevant anyway?

At that point we should also factor in time relativity, making it hard to measure the actual location of the stars at all.

This also doesn't handle new bars being opened and closed as you travel. Not to mention bouncers having bad days so you will have to revisit the bar.

I don't think this is presented as a means to get drunk around south korea. It's just an interesting application of TSP

But they are so far apart and move on roughly the same trajectory that it shouldn't really matter.

That's not true. The tour is 16.2 billion light years long, so even at the speed of light, it would take more than the current age of the universe to travel. Stars will move a lot over that period of time.

Yes I was assuming instant travel, even with one star the trajectory will be nonlinear.

That doesn't make sense to me. If you're assuming instant travel, then of course you don't need to account for stellar drift. Your response talking about stars "moving on roughly the same trajectory" doesn't make sense in that context. And anyway the GP was obviously not talking about instantaneous travel.

Unfortunate - they didn't pin the version of Three.js they were using for the interactive viewer at https://www.math.uwaterloo.ca/tsp/star/star10m_tour.html

And as a result it's been broken since May 2022: https://github.com/mrdoob/three.js/releases/tag/r141

I downloaded the HTML file and replaced the link with a versioned one, and the viewer still works just fine.

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