how does the Klein bottle exist in 4D?

Question

I can’t comprehend it

In: Mathematics

Answer 1

Let’s think with portals!

[Imagine a Klein bottle like this instead](https://i.imgur.com/V3WnGpX.png). The portals mean that the outer surface is completely smooth even though the tube connects through it.

Now imagine instead of portals, the tube and outer surface cross in the 4th dimension. So that, like with portals, the outer surface is completely smooth and unbroken, and the tube is complete but also goes through it.