Greg Egan on Nostr: I think I learned about this from Wikipedia. In 2019 I posted this on Twitter: ...

I think I learned about this from Wikipedia. In 2019 I posted this on Twitter:

Here’s my favourite immersion of Klein’s bottle. The region just inside each loop of the figure 8 is continuous with that just outside the other loop, so a Möbius-like-twist connects the two sides.

Then by splitting the surface in two (locally), you get an immersion of a torus!