Tag Archives: mobius

Moxi: the cartesian product of the mobius-strip and an interval

MoxI is a solid Klein bottle, the genus one nonorientable handlebody. Here we see it with some typical curves on


look a rough view

another earlier


Filed under cucei math, fiber bundle

geodesics in the band with better numerical resolution

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Filed under differential equations, differential geometry, geometry

perturbated core curve

the core curve of the mobius strip perturbated by 0.1\cos(11\ t) 

But if we use 0.4\cos(12.5t)\sin(3t)\cos(t)



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four geodesics in the band

on the right of this post you can see 4 (approximately) geodesics in the mobius strip, one is transversal to the core curve and the others (three)  begin at that transversal… One almost can see that all geodesics in the surface have curvature but without 3d torsion… would it be a theorem?  

Rendered with Mathematica-6.

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Filed under fiber bundle, multilinear algebra, topology

a non orientable 3d-manifold with boundary

Mö x I

Mö x I

The picture on the right is representation and a description of its parts of  a 3d chunk, it is the trivial I-bundle over the möbius-strip, M\ddot{o}\times I. It is  useful to determine which 3d spaces are non orientable.

A 3d-space is non orientable if it has a simple closed curve whose 3d regular neighborhood is homeomorphic to the model of the picture.

If we denote by C\ddot{o} the core of the möbius strip, you can deduce for the curve C\ddot{o}\times\{\frac{1}{2}\} (the black pearled one) that its tangent bundle can’t be embedded in the tangent bundle of \mathbb{R}^3 or in any other tangent bundle of an orientable one.

Remember N_2 is the Klein bottle. Let’s the image talks by itself.

Ah, il nome di questo grande pezzo è la bottiglia solida di Klein.


Filed under fiber bundle, geometry, topology


moebio10In math there is a geometric-topologic construction which is a source of fun and surprises. It is surface. It is a two dimensional object which can be embed in the three dimensional euclidean space, \mathbb{R}^3. It is a model to illustrate the concept of twisted bundle. In fact an I-bundle, an interval bundle over the circle.  The möbius band or möbius strip is the principal element to construct all the non orientable surfaces: N_1 the projective plane; N_2 the Klein bottle; N_3; N_4,… etc.

What happens if we remove the core central simple closed curve? look at the 2nd image.

I had spended many eons to popularize the symbol


for her. Isn’t this is beautiful?moebio20

The möbius band is employed to manufature many exotic non orientable three dimensional spaces. By the record, talking about 3d spaces:  \mathbb{R}^3 isn’t the only one.

For example M\ddot{o}\times I is a solid Klein bottle and an innocent quiz is: can you see what is the bounding surface of this I-bundle?

For a bundle of additional properties check this link

The images were rendered in Mathematica v.5

La siguiente figura te explica como ver una construcción tridimensional que involucra a la banda…

Mö x I

Aquí estamos usando N_2 para la superficie de género dos no orientable,,


Filed under cucei math, fiber bundle, low dimensional topology, topology