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The topologist’s world map (2020)

tafc.space

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Re: The topologist’s world map (2020)

#3
This is beautiful, especially with the colors on the top right - though I have a nitpick that it is missing an entire continent (probably because it doesn't show up in a list of countries): Antarctica

Edit: I now realize it's only supposed to show the graph national borders, though on a political world map, Antarctica is still shown. In a topological fashion, it could be added as a white circle around the entire map.

Re: The topologist’s world map (2020)

#10
For people who have time to burn being uselessly pedantic, is this a topologist's world map up to homotopy equivalence or homeomorphism?

[edit]

I think I get how to encode a hypergraph as a topological space. Let S be a set consisting of two kinds of points: Nodes and hyperedges. Endow it with a topology whose base consists of singleton sets containing only single nodes, and sets containing a hyperedge together with all the nodes it's connected to. In particular, a hyperedge cannot be in an open set unless it's accompanied by the nodes it's connected to. Observations are: The resulting space is usually not T2 or T1, but is always T0; connectivity of the hypergraph is equivalent to connectivity of the topological space; the Sierpinski space results from using a graph with one node and edge.

I don't know what that accomplishes except validate the intuition that graph theory is somehow connected to topology.

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