why am I seeing klein bottle videos now
what have you done to my search history

~author/streamer/gamedev~ appreciator of colorful wigs
why am I seeing klein bottle videos now
what have you done to my search history
Or another way of putting it is that it's a bottle-like shape for which the inside and outside are actually the same surface, in exactly the same way that the front and back of a mobius strip are the same side.
A less-absolutely-simplified description, yup. Weird geometry is fun, if hard to reasonably explain.
it's basically the mobius strip but More; it's just what happens when you try to make it so going up/down works like a mobius strip, with eventually ending up on the opposite side of where you started, but going left/right does the same thing - and going any other direction too. With the minor caveat that, if you try to put the bottle in 3 dimensions, it will have to cross through itself at some point.
(and if you're not comfortable with mobius strips yet, this perspective of klein bottles would be something to leave for the future)
Also, if I recall right, bisecting a klein bottle gets you two mobius strips of opposite chirality.
If you see the videos you see one of my favorite people in math, Cliff Stoll! He's so excited about everything it's hard not to get excited too!