Portals with an impossible shape (cylinder, Mobius strip, knot)

I visualized other very strange portals, most of which was discovered by a professional mathematicians. --- Chapters: 00:00 - Cylindrical portal 01:34 - Intro 02:02 - Mobius strip 04:31 - Mobius monoportal 05:17 - Hopf link 05:43 - Trefoil knot 13:11 - Other portals 14:18 - Outro --- Links: [1] - https://youtu.be/1zgBwQVr-wI - video about portal in a portal [2] - https://youtu.be/DTcfaHfDCEc - video about portal with three parts [3] - https://kenbrakke.com/polycut/polycut.htm - PolyCut [4] - https://www.youtube.com/watch?v=vFLZ2NGtuGw - ZenoRogue video about knot portals [5] - https://go.2gis.com/z95v9 - cubic trefoil knot in Almaty, Kazakhstan [6] - https://www.youtube.com/watch?v=IKSrBt2kFD4 - portal to Narnia by Bill Thurston [7] - https://www.imaginary.org/program/knotportal - KnotPortal program [8] - https://contest.zenmagnets.com/56-5-cubic-figure-eight-knot-created/ - cubic figure-eight knot by ZenMagnets [9] - http://paulbourke.net/geometry/borromean/ - variants for Borromean rings [10] - https://optozorax.github.io/portal/ - my web demo [11] - https://www.youtube.com/watch?v=TluRVBhmf8w - portal trailer (music source) --- Music: - Where We Wanna Go - Patrick Patrikios - Stick Bug song - Bee Swarm Simulator - 4000 Degrees Kelvin - Portal OST